The present invention relates generally to spark generating devices having a shavable pyrophoric element, and in particular to manually operated mechanical spark generating devices.
Spark generating or “fire starter” devices are generally well-known. However, known spark generating devices tend to be complex devices having multiple components. For example, most known spark generating devices include at least two separate components that must be operated together for generating sparks. Furthermore, the multiple components of known spark generating devices require the use to two hands.
Accordingly, known spark generating devices are limited in their ability to provide ease of use in challenging circumstances.
The present invention is a novel mechanical spark generating device structured for one-handed use.
According to one aspect of the invention the novel mechanical spark generating device includes a case having a case body, and a flexibly resilient striker arm extended from one surface of the case body. The case body includes a linear channel having an opening thereinto adjacent to an impact surface of the case body, and the striker arm includes a distal end thereof opposite from its attachment to the case body and positioned adjacent to the opening into the channel of the case body. A pyrophoric rod assembly is slidably carried in the channel of the case body. The pyrophoric rod assembly includes a rod carrier that is formed with a rod receiver cavity and with a support surface adjacent to one end, and a pyrophoric rod that is replaceably received into the rod receiver cavity. A striker bar is formed of a substantially hard material, such as a hardened stainless steel or carbide material, that will cooperate with pyrophoric rod 38 to generate sparks. The striker bar is positioned adjacent to the distal end of the striker arm in a position adjacent to the opening into the channel of the case body so that it is positioned for interacting with at least a portion of the pyrophoric rod of the pyrophoric rod assembly when the pyrophoric rod assembly is configured in a deployed configuration extended from the impact surface of the case body, and the striker arm is resiliently deflected inwardly there toward.
According to another aspect of the novel mechanical spark generating device, the novel mechanical spark generating device further includes a decoupleable latching mechanism that is operable between the rod carrier of the pyrophoric rod assembly and the channel of the case body for retaining the pyrophoric rod assembly substantially completely enclosed within the channel in an undeployed configuration.
According to another aspect of the novel mechanical spark generating device, with the striker arm deflected inwardly toward the case body, the striker bar is further positioned for interacting with at least a portion of the pyrophoric rod of the pyrophoric rod assembly during travel of the pyrophoric rod assembly between the deployed configuration and the undeployed configuration.
According to another aspect of the novel mechanical spark generating device, the novel mechanical spark generating device further includes a spring or other biasing member that is positioned between the pyrophoric rod assembly and the case body, such that the biasing member is deflected in a potential energy state when the pyrophoric rod assembly is in the undeployed configuration, and the biasing member is undeflected in a substantially expended energy state when the pyrophoric rod assembly is in the deployed configuration.
According to another aspect of the novel mechanical spark generating device, the novel mechanical spark generating device further includes an activation mechanism that is operable between the distal end of the striker arm and the rod carrier of the pyrophoric rod assembly for decoupling the decoupleable latching mechanism.
According to another aspect of the novel mechanical spark generating device, the novel mechanical spark generating device further includes a brake mechanism that is operable between the pyrophoric rod assembly and the case body for stopping progression of the pyrophoric rod assembly during travel toward the deployed configuration, and retaining the pyrophoric rod assembly partially within the case body when the pyrophoric rod assembly is in the deployed configuration.
According to another aspect of the novel mechanical spark generating device, the pyrophoric rod assembly is further substantially completely retracted within the channel of the case body when it is configured in the undeployed configuration.
According to another aspect of the novel mechanical spark generating device, a novel one-handed method of mechanically generating sparks is disclosed in detail.
Other aspects of the invention are detailed herein.
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
In the Figures, like numerals indicate like elements.
The Figures illustrate a novel mechanical spark generating device 10 that is manually operable for generating a spark, e.g., causing ignition of fuel for starting a fire.
Case halves 14a, 14b combine to form a flexibly resilient striker arm 24 along one side of case 14. Striker arm 20 holds a metallic striker bar 26 in a position for interacting with pyrophoric rod assembly 12 when striker arm 24 is resiliently deflected inwardly there toward (arrow 28) during operation, as disclosed herein. Mated case halves 14a, 14b form a striker control pad 30 on a surface of striker arm 24 external of case 14. Striker control pad 30 is operated for resiliently deflecting striker arm 24 against case body 16 and thereby compressing striker bar 26 into operative contact with pyrophoric rod assembly 12. Mated case halves 14a, 14b also optionally form a protective spur 32 on an external surface of striker arm 24 at distal end of striker control pad 30 adjacent to striker bar 26. Protective spur 32 is useful for protecting the users thumb on striker control pad 30 from experiencing hot particles of pyrophoric alloy generated during operation of spark generating device 10.
When pyrophoric rod assembly 12 is urged out of case body 16 by spring force of biasing member 46, pressure applied to striker control pad 30 compresses (arrow 28) striker bar 26 into operative contact with pyrophoric rod 38. In turn, pressure of striker bar 26 against pyrophoric rod 38 forces back surface 54 of rod carrier 40 into contact with guide 50 in mouth 52 of channel 42. Compression of pyrophoric rod 38 and rod carrier 40 between striker bar 26 and channel guide 50, respectively, cooperates with shoulder 44 of rod carrier 40 against an interior wall 56 of channel 42 opposite from guide wall 50 to effectively stabilize pyrophoric rod assembly 12 in channel 42, even when pyrophoric rod assembly 12 is mostly extended from mouth 52 of channel 42.
A decoupleable latching mechanism 58 is provided between pyrophoric rod assembly 12 and channel 42 to retain pyrophoric rod assembly 12 in channel 42 until activated. For example, latching mechanism 58 is provided between base portion 48 of channel 42 and shoulder 44 of rod carrier 40, as disclosed herein.
A brake mechanism 59 is provided between pyrophoric rod assembly 12 and channel 42 for preventing pyrophoric rod assembly 12 from completely exiting mouth 52 of channel 42. For example, channel 42 is formed with a stop 60 adjacent to mouth 52 and rod carrier 40 includes a brake member 62 that cooperates with stop 60 to arrest progress of pyrophoric rod assembly 12 from mouth 52 of channel 42. Other brake mechanisms 59 are also contemplated and may be substituted without deviating from the scope and intent of the present invention.
Striker arm 24 is resiliently deflectable toward (arrow 28) pyrophoric rod assembly 12 for causing striker bar 26 to interact with pyrophoric rod 38 during operation of spark generating device 10. For example, case 14 is formed with a gap 64 between striker arm 24 and body 16 for normally spacing striker bar 26 away from pyrophoric rod 38, except during operation. Case halves 14a, 14b are formed of a substantially rigid but resilient material, such as injection molded plastic, whereby when assembled in case 14, striker arm 24 is flexibly spaced away from case body 16 by gap 64. A stress relief notch 66 is optionally formed at root of gap 64 between striker arm 24 and case body 16 to ensure longevity of case 14.
Case halves 14a, 14b are assembled into case 14 by fitting the plurality of flexibly resilient teeth 18 in one case half 14a interlockably into mating receiver notches 20 in mating case half 14b. Accordingly, case halves 14a, 14b are snapped together for ease of assembly. Assembled case halves 14a, 14b form case body 16 and flexible striker arm 24 of case 14.
As illustrated, pyrophoric rod assembly 12 is formed of pyrophoric rod 38 installed into rod carrier 40. For example, pyrophoric rod 38 is sized slightly longer than a rod receiver cavity 70 of rod carrier 40, such that pyrophoric rod 38 is a lengthwise snap fit into rod carrier 40. Accordingly, pyrophoric rod 38 is easily changed after extended use has ended its useful life. However, pyrophoric rod 38 is substantially cylindrical in shape such that it can be turned within rod receiver cavity 70 to expose a different, unworn surface to striker bar 26 after one surface becomes worn from use. As disclosed herein, pyrophoric rod 38 is a pyrophoric alloy, such as ferrocerium which is a man-made metallic material having a high coefficient of pyrophoricity such that it has the ability to give off a large number of hot sparks when scraped against a rough surface such as ridged steel.
Spring biasing member 46 is a conventional compression spring installed into cavity 42 formed between assembled case halves 14a, 14b. Pyrophoric rod assembly 12 is installed into cavity 42 with pyrophoric rod 38 facing toward striker bar 24 in striker arm 24. Pyrophoric rod assembly 12 is pushed down into cavity 42 of case 14 to compress spring biasing member 46 between shoulder 44 of rod carrier 40 and base portion 48 of channel 42. Spring biasing member 46 is positioned for urging rod carrier 40 out of case body 16 along channel 42.
An optional cover 72 may be fitted over case 14. For example, optional cover 72 is formed of an elastic material, such as a synthetic rubber material having a higher coefficient of friction than the injection molded plastic or other material of case 14. Optional cover 72, if present, thus provides added grip to spark generating device 10. According to one embodiment, optional cover 72, if present, includes an opening 74 for receiving assembled case 14 into an internal cavity 76. Optional cover 72 is optionally formed with a knurled or ribbed panel 78 in a position to fit over striker control pad 30 on striker arm 24. Optional ribbed panel 78 maximizes user's grip on striker control pad 30. A second ribbed panel 78 is optionally provided on a surface 80 opposite from striker arm 24 for added gripping capability. When lanyard loop 22 is present in case 14, optional cover 72 may include a corner cutout 82 positioned to expose lanyard loop 22. A opposing corner cutout 82 may be provided for aesthetics. Corner cutouts 82 are joined by a strap 84 of the elastic material to maintain integrity of cover 72 and act as a stop when fitted over case 14. Optionally, side surfaces 86 of cover 72 include a company or product logo. Else, cover 72 may include side cutouts 88 for exposing optional logos 90 embossed on case halves 14a, 14b.
Striker arm 24 is illustrated as being formed with an ejector head 102 on the distal end thereof opposite from external protective spur 32. Ejector head 102 is positioned adjacent to impact surface 36 of case 14 within mouth 52 of channel 42 opposite from guide wall 50 thereof. Ejector head 102 is thus positioned for being deflected toward (arrow 28) channel 42 in body 16 of case 14. Accordingly, ejector head 102 is positioned for ejecting pyrophoric rod assembly 12 when striker arm 24 is resiliently deflected there toward (arrow 28) during operation, as disclosed herein. Ejector head 102 carries striker bar 26. For example, ejector head 102 includes a retention slot 104 for holding striker bar 26 in a position for interacting with pyrophoric rod assembly 12 during operation of striker arm 24, as disclosed herein. For example, retention slot 104 is positioned on the ejector head 102 adjacent to mouth 50 of channel 42 and impact surface 36 of case 14. Retention slot 104 may extend into wings 106 of striker arm 24 that extend outside of ejector head 102, and thus outside of channel 42 to avoid interference with operation of pyrophoric rod assembly 12. Retention slot 104 and wings 106 are symmetrically formed in striker arm 24 within each half 14a, 14b of case 14. Striker bar 26 is thus nested in retention slot 104 of ejector head 102 opposite from external protective spur 32 and between wings 106.
Alternatively, details of latching mechanism 58 are reversed between channel 42 of body 14 and shoulder 44 of rod carrier 40 without deviating from the scope and intent of the present invention. In other words, anchor portion 108 of latching mechanism 58 is optionally formed in base portion 48 of channel 42, while receiver portion 92 is formed in base of rod carrier 40. Additionally, alternative embodiments of latching mechanism 58 are also contemplated and may be substituted without deviating from the scope and intent of the present invention.
Shoulder portion 44 of rod carrier 40 is further structured to retain biasing member 46 in an operative position between pyrophoric rod assembly 12 and channel 42. According to one embodiment, shoulder portion 44 is optionally formed with a cavity 118 having an opening 120 in a bottom surface of rod carrier 40. Cavity 118 is sized to fit loosely about arms 94 of receiver portion 92 with spring biasing member 46 nested in between, as disclosed herein. Cavity 118 is further deep enough to compress spring biasing member 46 between a base surface 122 thereof and base portion 48 of channel 42.
Rod carrier 40 is formed with an ejector head reaction surface 124 positioned adjacent to support surface 34 adjacent to one end of pyrophoric rod assembly 12 and opposite from pyrophoric rod carrier back surface 54. Ejector head reaction surface 108 is thus positioned to cooperate with ejector head 102 on the distal end of striker arm 24 when pyrophoric rod assembly 12 is installed in channel 42. Ejector head reaction surface 124 is inclined for more effectively interacting with ejector head 102 of striker arm 24. As disclosed herein, reaction surface 124 is responsive to force from ejector head 102 when pressure is applied to striker control pad 30 of striker arm 24 for releasing latching mechanism 58 between pyrophoric rod assembly 12 and case 14.
Operation of spark generating device 10 is initiated or “triggered” by an activation or “trigger” mechanism 127 operable between striker arm 24 and pyrophoric rod assembly 12 for decoupling latching mechanism 58 and releasing pyrophoric rod assembly 12 for moving within channel 42. By example and without limitation, activation mechanism 127 is provide by ejector head 102 of striker arm 24 interacting with inclined ejector head reaction surface 124 of rod carrier member 40 of pyrophoric rod assembly 12.
Accordingly, operation of spark generating device 10 is triggered by application of compressive activation force (arrow 128) to striker control pad 30 on exterior surface of striker arm 24. Compressive activation force 128 on striker control pad 30 forcibly deflects ejector head 102 inwardly toward (arrow 28) channel 42 in body 16 of case 14 and into contact with inclined ejector head reaction surface 124 of rod carrier 40 adjacent to one end of pyrophoric rod assembly 12. Forceful contact of ejector head 102 with inclined ejector head reaction surface 124 laterally forces back surface 54 of rod carrier 40 into contact with channel guide 50, which arrests lateral movement of pyrophoric rod carrier within channel 42. Continued application of compressive activation force 128 redirects loading of ejector head 102 on inclined ejector head reaction surface 124 into an ejection force (arrow 130) directed substantially longitudinally of channel 42 for forcing rod carrier 40 along channel 42 outwardly (arrow 126) of case impact surface 36.
Redirection of loading of ejector head 102 on inclined ejector head reaction surface 124 longitudinally of channel 42 in turn loads latching mechanism 58 with longitudinal ejection force 130. Firing of pyrophoric rod assembly 12 occurs when longitudinal ejection force 130 overloads retention strength of latching mechanism 58, which decouples latching mechanism 58. For example, shoulder portion 114 of anchor head 112 forcibly spreads arms 94 of bifurcated receiver portion 92 in base 48 of channel 42, and anchor head 112 is forced outwardly (arrow 126) from cavity 96. Barbed anchor 108 is thus released from receiver portion 92 of latching mechanism 58. After this decoupling of latching mechanism 58, compressed spring biasing member 46 expands between opposing bases 48, 122 of case channel 42 and shoulder 44 of rod carrier 40. Spring force of expanding biasing member 46 operates for urging pyrophoric rod assembly 12 along channel 42 outwardly (arrow 126) of case 14 like a jack-in-the-box.
Ejection motion of pyrophoric rod assembly 12 along channel 42 outwardly (arrow 126) of case 14 is arrested by operation of brake mechanism between pyrophoric rod assembly 12 and channel 42. For example, contact of brake member 62 with stop 60 adjacent to mouth 52 of channel 42 overcomes force of expanding biasing member 46 and forcibly arrests motion of pyrophoric rod assembly 12 along channel 42 outwardly (arrow 126) of case 14.
Other decoupleable latching mechanism 58 are also contemplated and may be substituted without deviating from the scope and intent of the present invention.
Other activation mechanisms 127 are also contemplated and may be substituted without deviating from the scope and intent of the present invention.
Metallic striker bar 26 and pyrophoric alloy rod 38 function similarly to traditional flint-and-steel. In traditional flint-and-steel fire-starting systems, using actual flint, tiny shavings of the steel that are removed in the striking process are what burn, rather than the flint. Here, metallic striker bar 26 functions as the flint, and pyrophoric alloy rod 38 functions as the steel in generating burning sparks for starting a fire.
As disclosed herein, striker bar 26 provides means for shaving pyrophoric particles from the pyrophoric rod 38 and simultaneously igniting them. Compressive activation force 128 is applied to striker control pad 30 for forcibly deflecting striker bar 26 into operative contact with pyrophoric rod 38, as shown. While striker bar 26 remains forcibly deflected into operative contact with pyrophoric rod 38, striking force (arrow 134) is rapidly applied to case 14 in a striking direction (arrow 136) toward surface 132. As case 14 is forced to travel rapidly toward surface 132, compressive activation force 128 causes striker bar 26 to scrape along pyrophoric rod 38, which in turn scrapes small shavings 138 of the pyrophoric alloy. When small shavings 138 of the pyrophoric alloy are removed quickly enough, heat generated by friction is enough to ignite shavings 138 into a shower 140 of hot sparks. The basis for easy sparking of pyrophoric alloys, such as ferrocerium, is their low temperature pyrophoricity. The ignition temperature of ferrocerium is between 150 and 180 degrees Celsius.
The angular configuration of striker bar 26 relative to pyrophoric rod 38 is unnecessary for practicing the invention. However, inclination of striker bar 26 relative to pyrophoric rod 38 forces ignited shavings 138 generated during travel of case 14 over pyrophoric rod assembly 12 to be ejected outwardly (arrows 142) of mouth 52 of channel 42 and away from impact surface 36 and case 14. When it is desired to ignite wood or the like for a fire, support surface 34 of pyrophoric rod assembly 12 is positioned within or adjacent to paper, wood shavings or other kindling. With striker bar 26 forcibly deflected (arrow 28) into operative contact with pyrophoric rod 38, as shown, case 14 is forced rapidly in striking direction (arrow 136) toward surface 132, which causes striker bar 26 to scrape along pyrophoric rod 38, which in turn, produces small shavings 138 of the pyrophoric alloy rod 38 that are ignited into sparks by friction. The temperature of the sparks thus generated tends to ignite the kindling to form a flame.
Striking force (arrow 134) is arrested when impact surface 36 of case 14 approaches and impacts solid surface 132. Rod assembly 12 is automatically fully restored in channel 42 of case 14 when impact surface 36 impacts solid surface 132. Simultaneously, rod assembly 12 is re-cocked into the cocked state, having pyrophoric rod assembly 12 fully retracted into case 14 with spring biasing member 46 compressed between shoulder 44 of rod carrier 40 and base portion 48 of channel 42. Accordingly, user may redeploy pyrophoric rod assembly 12, as disclosed herein, for repeating spark generation sequence, or store spark generating device 10 if sufficient sparks have been generated for satisfactorily igniting the kindling.
As illustrated here, case 14 is further formed with a protective spur 144 on its external surface opposite from striker arm 24 for protecting the user's digits from impacts with solid surface 132 during the spark generation sequence.
Ejection of pyrophoric rod assembly 12 is forcibly arrested when brake member 62 contacts stop 60 adjacent to mouth 52 of channel 42, which overcomes force of expanding biasing member 46 and arrests outwardly (arrow 126) motion of pyrophoric rod assembly 12 along channel 42 of case 14.
Here, support surface 34 of pyrophoric rod assembly 12 is seated against a solid surface 132, such as earth, which holds pyrophoric rod assembly 12 substantially stationary. Rod assembly 12 is oriented with pyrophoric rod 38 facing generally toward adjacent kindling 158. With novel mechanical spark generating device 10 held approximately as indicated, user applies additional compressive activation force (arrow 128) to striker control pad 30 for forcibly deflecting striker arm 24 and engaging striker bar 26 with pyrophoric alloy rod 38. Thereafter, user rapidly applies striking force (arrow 134) to case 14 in striking direction (arrow 136) toward surface 132. During travel of case 14 toward surface 132, striker bar 26 is caused to scrape along pyrophoric rod 38, which produces small shavings 138 of the pyrophoric alloy rod 38 that are ignited into shower 140 of hot sparks by friction.
The angular configuration of striker bar 26 relative to pyrophoric rod 38 forces ignited shavings 138 to be ejected as shower 140 of sparks outwardly (arrows 142) of mouth 52 of channel 42 adjacent to impact surface 36 of case 14. The hot sparks thus generated tend to ignite kindling 158 to form a flame. If initial spark generation is inadequate for igniting kindling 158, for example in windy conditions, this spark generation sequence may be repeated as often as necessary.
A final operation of spark generating device 10 through the spark generation sequence leaves pyrophoric rod assembly 12 retracted and interlocked with case 14, whereupon spark generating device 10 is configured in a condition safe for storage and carrying.
The angular configuration of striker bar 26 relative to pyrophoric rod 38 forces ignited shavings 138 to be ejected as shower 140 of sparks outwardly (arrows 142) of mouth 52 of channel 42 adjacent to impact surface 36 of case 14. Protective spur 32 on external surface of striker arm 24 serves to protect user's digits, i.e., middle finger 150 and ring finger 152, from shower 140 of hot sparks, while rod carrier 40 protects index finger 148.
This initial spark generation sequence leaves pyrophoric rod assembly 12 retracted and interlocked with case 14, whereupon spark generating device 10 is configured in a condition safe for storage and carrying. However, spark generation sequence may be repeated as often as necessary for igniting kindling 158, and each repetition of the spark generation sequence leaves pyrophoric rod assembly 12 retracted and interlocked with case 14.
While the preferred and additional alternative embodiments of the invention have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. Therefore, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.
Accordingly, the inventor makes the following claims.
This application claims priority benefit of copending U.S. Provisional Patent Application Ser. No. 61/191,064 filed in the names of the above captioned inventors, the common inventors hereof, on Sep. 4, 2008, the complete disclosure of which is incorporated herein by reference.
Number | Date | Country | |
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61191064 | Sep 2008 | US |