US3486075A - Piezoelectric igniter - Google Patents

Piezoelectric igniter Download PDF

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Publication number
US3486075A
US3486075A US703760A US3486075DA US3486075A US 3486075 A US3486075 A US 3486075A US 703760 A US703760 A US 703760A US 3486075D A US3486075D A US 3486075DA US 3486075 A US3486075 A US 3486075A
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US
United States
Prior art keywords
piezoelectric
housing
igniter
striking
flange
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US703760A
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English (en)
Inventor
Leo Steinke
Gerhard Sohner
Kurt Hurst
Richard Gerber
Karl Frimmel
Otto Herrmann
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Robert Bosch GmbH
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Robert Bosch GmbH
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Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
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Publication of US3486075A publication Critical patent/US3486075A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23Q—IGNITION; EXTINGUISHING-DEVICES
    • F23Q3/00—Igniters using electrically-produced sparks
    • F23Q3/002—Igniters using electrically-produced sparks using piezoelectric elements

Definitions

  • FIGA A first figure.
  • the present invention relates to improvements in piezoelectric igniters, particularly to improvements in igniters which may be utilized for ignition of gaseous fuels. Still more particularly, the invention relates to igniters which can be used to ignitiate combustion of hard-toignite gases, especially city gas, butane, natural gas and/ or others.
  • the blow transmitted to a piezoelectric elment causes a change in the mechanical stress which effects the discharge of a single spark across a spark gap.
  • the spark produced by the blow is of short duration and does not always suffice to insure ignition of certain types of gaseous fuels, for example, butane or natural gas. Therefore, such igniters are normally employed for ignition of readily combustible gases, particularly pressurized gaseous lighter fuel.
  • U.S. Patent No. 3,200,295 discloses a lighter for ignition of pressurized gaseous lighter fuel by piezoelectric means.
  • Another object of the invention is to provide the igniter with a striking device which invariably transmits to the piezoelectric means blows of identical magnitude and which takes advantage of the reversibility of the piezoelectric effect to insure that the generation of sparks proceeds during a relatively long interval of time which is ample to effect ignition of butane, natural gas or similar hard-to-ignite gaseous fuels.
  • the improved piezoelectric igniter comprises means forming a spark gap; piezoelectric means including at least one piezoelectric element, electrodes electrically connected with the piezoelectric means and with the sides of the spark gap, striking means having a predetermined mass and movable toward and away from the piezoelectric means, and biasing means arranged to propel the striking means toward the piezoelectric means with a force exactly tuned to the mass of the striking means so that the striking means imparts to the piezoelectric means a blow of predetermined magnitude to cause a sudden first change in the mechanical stress therein resulting in potential difference of first polarity between the sides of the spark gap and in the discharge of at least one primary spark across and an ionization of the spark gap.
  • the first change in the mechanical stress is thereupon followed by a gradual second change in response to termination of the blow and results in a potential difference of opposite polarity to effect at least one secondary discharge across the ionized spark gap. If the primary spark or sparks fail to ignite a hard-to-ignite gaseous fuel, the secondary discharge suffice to effect ignition even of very hard-to-burn gases, such as city gas, butane, natural gas and/or others.
  • FIG. 1 is an axial sectional view of a piezoelectric igniter which embodies our invention, the striking means being shown in starting position;
  • FIG. 2 is a partly elevational and partly axial sectional view of the housing in the piezoelectric igniter, the striking means being shown in blow-transmitting position;
  • FIG. 3 is a diagram showing the manner in which the mechanical stresses in the piezoelectric elements vary during and subsequent to transmission of a blow.
  • FIG. 4 is a diagram showing the manner in which the potential difference at the electrode varies during and subsequent to transmission of a blow.
  • the piezoelectric igniter of FIGS. 1 and 2 comprises a tubular housing 10 which is open at one end and comprises an end wall 10a at the other end.
  • the housing 10 is grounded and accommodates a cylindrical anvil 11 abutting against an elastic cushion 12 which is adjacent to the inner side of the end wall 10a. That surface of the anvil 11 which faces away from the end wall 10a is provided with a cylindrical recess 11a for the lower end portion of an insulating sleeve 13 which surrounds two stacked piezoelectric elements 14 of cylindrical shape.
  • the elements 14 are connected in parallel and their opposite poles are adjacent to each other.
  • poles are connected with a central electrode which extends from the housing 10 through a radial nipple 13b of the sleeve 13.
  • the latter is further provided with an external projection or collar 13a which is fitted into the housing 10.
  • This collar 13a forms part of anchoring means for the sleeve 13, and such anchoring means further includes one, two or more internal projections of lugs 1012 provided in the housing 10 and a spring 16 which is inserted between the projections 10b and collar 13a to bias the sleeve 13 against the anvil 11 and to thus prevent recoiling or rebounding of the sleeve when the upper piezoelec' tric element 14 receives a blow.
  • the upper portion of the sleeve 13 is surrounded by a helical return spring 17 which operates between the collar 13a and an internal surface of a cupped striking member 18.
  • the latter is reciprocable in the housing 10 toward and away from the upper piezoelectric element 14.
  • the striking member 18 has a lower end surface which is provided with a recess serving to accommodate a portion of the return spring 17.
  • the upper end portion of the striking member 18 is of reduced diameter and is provided with a flange 19 which can be engaged by the lower end portions 26 of elastic claws 20 installed in the upper part of the housing 10.
  • the flange 19 serves as an abutment for the lowermost convolution of a helical spring 21 which constitutes a biasing means and serves to propel the striking member 18 against the upper piezoelectric element 14 when the lower end portions 26 of the claws 20 are disengaged from the flange 19 by the lower end face of a cylindrical actuating member or knob 22 which is reciprocable in a mounting ring 24 connected with the upper end portions of claws 20 and held in the top part of the housing 10 by a nut 25 which meshes with an externally threaded portion of the housing.
  • the knob 22 has two, three or more equidistant radially outwardly extending arms 22a which are slidable along the internal surface of the housing 10.
  • a guide pin or post 23 of the striking member 18 extends upwardly beyond the flange 19 and is surrounded by the c nvolutions of the spring 21.
  • This post 23 serves as a guide for the knob 22 when the latter is depressed to stress the spring 21 and to move its lower end face 22b into engagement with suitably configurated cams 27 pr vided on the claws 20 directly above the respective lower end portions 26.
  • the claws 20 yield in response to downward movement of the knob 22, and their disengagement from the flange 19 takes place upon requisite stressing of the spring 21 so that the latter overcomes the resistance of the return spring 17 and propels the striking member 18 against the upper piezoelectric element 14.
  • the retaining means including the claws 20 and mounting ring 24 preferably consists of suitable synthetic thermoplastic material.
  • FIG. 1 shows the striking member 18 in a starting position in which the surface at the upper end of the recess in this striking member is remote from the upper piezoelectric element 14.
  • the arms 22a of the knob 22 passes through two of the claws 20.
  • the operator applies finger pressure against the upper end of the knob 22 so as to move the arms 22a along the internal surfaces of the housing 10 and to stress the spring 21.
  • the lower end face 22b of the knob 22 engages the cams 27 when the spring 21 stores sufficient energy, and further depression of the knob causes the end portions 26 of the claws 20 to move away from the flange 19 so that the spring 21 is free to dissipate energy and to propel the striking member 18 against the upper piezoelectric element 14.
  • the striking member imparts to this element 14 a blow of predetermined magnitude to cause a first change in the mechanical stress in the piezoelectric elements 14.
  • the spring 21 is much stronger than and can readily overcome the opposition of the return spring 17 when the knob 22 is depressed to the extent necessary to disengage the claws 20 from the flange 19 of the striking member 18.
  • the operator then releases the knob 22 so that the spring 17 is free to expand and to return the striking member 18 to the starting position shown in FIG. 1.
  • the faces of the end portions 26 of claws 20 are inclined downwardly and outwardly in order to permit upward movement of the flange 19 so that this flange is reengaged by the claws and is held in the starting position.
  • the expanding return spring 17 need not overcome the resistance of the spring 21 because the operator removes his or her finger from the knob 22 as soon as the claws 20 release the flange 19.
  • FIGS. 1 and 2 show that the flange 19 resembles a short frustrum of a cone and tapers upwardly to facilitate its passage along the lower faces of the end portions 26 and back to the starting position.
  • the mass of the striking member 18 is about 45 grams, and the mass of the anvil 11 is greater, preferably about twice the mass of the striking member.
  • the mass of the striking member 18 and the characteristics of the spring 21 are tuned to each other in such a way that the mechanical stresses in the piezoelectric elements 14 change substantially or exactly in a manner as shown in FIG. 3 while and immediately after the striking member 18 imparts a blow in response to disengagement of its flange 19 from the claws 20.
  • the maximum mechanical stress (P is about 300 kp. and the stress rises substantially in the same way as the no-load potential difference between the sides of the piezoelectric elements 14 with a maximum of about 17 kv.
  • the sides 28a, 28b of a spark gap 28 are respectively connected with the electrode 15 and with the ground.
  • the housing 10 constitutes a second electrode which is electrically connected with the side 28b and with the two outer poles of the piezoelectric elements 14.
  • the striking member 18 is metallic and is in current-conducting contact with the grounded housing 10. When the striking member 18 imparts a.
  • a gradual second change in mechanical stressing of the piezoelectric elements 14 occurs on termination of the blow.
  • Such second change is the reduction of mechanical stress and produces a potential difference of opposite polarity as shown in FIG. 4.
  • This second potential difference causes an arc discharge or secondary discharge across the ionized spark gap 28, and such secondary discharge is terminated after an interval of about 7 microseconds following the primary discharge.
  • the entire ignition process takes up an interval of at least ten microseconds.
  • Readily combustible gases are ignited in response to one or more primary discharges.
  • City gas, butane or like gases which are not readily combustible are normally ignited in response to secondary discharge across the spark gap 28.
  • the duration of secondary discharge can be extended for one or several microseconds by placing the spark gap forming means in series with a suitable resistor 29, e.g., an ohmic resistor and/ or an inductive resistor.
  • a suitable resistor 29 e.g., an ohmic resistor and/ or an inductive resistor.
  • the resistor 29 may constitute a conventional anti-interference cable of the type often employed in internal combustion engines. Such cable may have an inductance of 5-50 microhenry an an ohmic resistance of 530 kiloohms.
  • Our invention is based on the recognition that certain hard-to-ignite gases can be ignited if they are brought into contact with an arc discharge of relatively long duration and if such discharge generates a certain minimum amount of heat energy. This is achieved by relating the mass of the striking member and the bias of the spring 21 to each other in such a way that there develops a sudden rise in mechanical stress upon the piezoelectric elements 14 when the striking member imparts a blow so that the rise in mechanical stress suffices to produce a primary spark and to cause ionization of the spark gap 28. When the mechanical stress decreases upon termination of the blow, the resulting potential difference suflices to cause one or more secondary discharges across the ionized spark gap. The total interval of discharge is thus extended to at least ten microseconds in order to insure the ignition of nearly all types of gaseous fuels.
  • the utilization of the resistor 29 is of particular advantage if the piezoelectric means comprises two parallel-connected piezoelectric elements which double the amount of electrical energy that develops in response to transmission of a blow and subsequent to termination of the blow.
  • the manner in which the spark gap 28 can be placed adjacent to a main gas line or a pilot line is known and forms no part of the present invention.
  • a piezoelectric igniter particularly for ignition of combustible gases, comprising, in combination, electrode means forming a spark gap; a housing; piezoelectric means located in said housing and including at least one piezoelectric element electrically connected in circuit with said electrode means; striking means in said housing and having a predetermined mass and being movable toward and away from said piezoelectric means for striking the same and thereby causing electric current to flow to said electrode means, creating an electric spark in said spark gap for igniting said combustible gases; biassing means arranged to propel said striking means towards said piezoelectric means; an anvil in said housing adjacent to said piezoelectric means opposite to said striking means and having a mass greater than that of said striking means; and elastic cushioning means interposed between said anvil and said housing opposite said piezoelectric means.
  • said housing is of tubular shape and comprises an end wall
  • said anvil is of cylindrical shape and is slidably guided in said housing
  • said cushioning means comprises a rubber plate sandwiched between said anvil and said end wall of said housing, said anvil abutting with the end thereof opposite said piezoelectric means against said plate.
  • said anchoring means comprising an external projection provided on said sleeve and slidably fitted into said housing, at least one internal projection provided on said housing and spring means operating between said projections to bias said sleeve against said anvil.
  • said striking means comprises a flange and including retaining means comprising elastic claw means engaging said flange for yieldably holding said striking means in a starting position remote from said piezoelectric means.
  • said biasing means comprises a helical spring interposed between said flange and said actuating means, said striking means having a guide pin surrounded by said helical spring.
  • said claw means comprises a plurality of equidistant claws having end portions engageable with said flange.
  • said claw means comprises a plurality of claws having first end portions engageable with said flange and second end portions, and mounting means connected with said second end portions and fixed to said housing.
  • said claw means comprises a plurality of elastic claws having end portions engaging said flange in starting position of said striking means and cams adjacent to such end portions and engageable by said actuating means to disconnect said end portions from said flange.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Ignition Installations For Internal Combustion Engines (AREA)
  • Air Bags (AREA)
  • Portable Nailing Machines And Staplers (AREA)
US703760A 1967-02-11 1968-02-07 Piezoelectric igniter Expired - Lifetime US3486075A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEB0091158 1967-02-11

Publications (1)

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US3486075A true US3486075A (en) 1969-12-23

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US703760A Expired - Lifetime US3486075A (en) 1967-02-11 1968-02-07 Piezoelectric igniter

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US (1) US3486075A (es)
AT (1) AT287900B (es)
BE (1) BE710606A (es)
CH (1) CH464832A (es)
DE (1) DE1629890B2 (es)
ES (1) ES350355A1 (es)
FR (1) FR1552537A (es)
GB (1) GB1221701A (es)
NL (1) NL146594B (es)
SE (1) SE337791B (es)

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3576383A (en) * 1968-08-02 1971-04-27 Ransen Corp Piezoelectric ignition mechanism
US3585417A (en) * 1969-03-06 1971-06-15 Mallory & Co Inc P R Piezoelectric device having a resistor and a plastic insulating casing
US3793561A (en) * 1971-12-23 1974-02-19 Swelex Teknik Ab Piezoelectric gas lighter
US3891381A (en) * 1973-03-31 1975-06-24 Mansei Kogyo Kk Spark ignitable cigarette lighter
US3949248A (en) * 1973-07-10 1976-04-06 Braun Aktiengesellschaft Piezoelectric igniter using resilient housing
US3967141A (en) * 1970-12-01 1976-06-29 Dynamit Nobel Aktiengesellschaft Piezoelectric energy source
US3984738A (en) * 1973-05-14 1976-10-05 Braun Aktiengesellschaft Piezoelectric igniter for lighters
US3992640A (en) * 1974-11-29 1976-11-16 Eastman Kodak Company Piezo crystal housing and mount
JPS51155173U (es) * 1975-06-03 1976-12-10
US4025817A (en) * 1974-09-03 1977-05-24 Eastman Kodak Company Trigger device for an electronic flash unit
JPS52102479U (es) * 1976-01-28 1977-08-03
JPS52105568U (es) * 1976-02-06 1977-08-11
JPS52109980U (es) * 1976-02-17 1977-08-20
JPS52140975U (es) * 1976-04-20 1977-10-25
JPS52168081U (es) * 1976-06-10 1977-12-20
US4315180A (en) * 1976-06-10 1982-02-09 Matsushita Electric Industrial Co., Ltd. High voltage piezoelectric generating device with lengthened spark time
US5262697A (en) * 1991-03-13 1993-11-16 Laforest Bic, S.A. Piezoelectric mechanism for gas lighters
US5798601A (en) * 1995-06-08 1998-08-25 Hansen; James M. Adjustable retrofit ignition kit for portable gas appliances
US5854530A (en) * 1996-12-18 1998-12-29 Bic Corporation Piezoelectric lighter which has a higher level of difficulty for operation
US5927962A (en) * 1995-12-04 1999-07-27 Laforest Bic, S.A. Piezoelectric mechanism for gas lighters with externally closed telescopic body
US6046528A (en) * 1997-11-03 2000-04-04 Bic Corporation Selectively actuatable piezoelectric ignition mechanism
US20230106153A1 (en) * 2021-10-05 2023-04-06 Vpr Brands, Lp Table-top lighters

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1386718A (fr) * 1963-02-27 1965-01-22 Sapphire Molectric Ltd Perfectionnements aux dispositifs d'allumage
US3200295A (en) * 1962-12-26 1965-08-10 Honeywell Inc Manually operable piezoelectric lighters
US3324317A (en) * 1965-01-21 1967-06-06 Magnavox Co Solid state inertial energy generatorstorage system
US3344314A (en) * 1963-11-20 1967-09-26 Honeywell Inc Igniter employing a piezoelectric voltage source
US3384786A (en) * 1965-12-28 1968-05-21 Mansei Kogyo Kk Manually operable piezoelectric gas lighters
US3387912A (en) * 1965-11-26 1968-06-11 Mansei Kogyo Kk Ignition mechanism of liquefied gas fueled lighter
US3408153A (en) * 1966-04-25 1968-10-29 Ishiguro Mitsuei Gas lighter with a manually operable piezoelectric ignition device

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3200295A (en) * 1962-12-26 1965-08-10 Honeywell Inc Manually operable piezoelectric lighters
FR1386718A (fr) * 1963-02-27 1965-01-22 Sapphire Molectric Ltd Perfectionnements aux dispositifs d'allumage
US3344314A (en) * 1963-11-20 1967-09-26 Honeywell Inc Igniter employing a piezoelectric voltage source
US3324317A (en) * 1965-01-21 1967-06-06 Magnavox Co Solid state inertial energy generatorstorage system
US3387912A (en) * 1965-11-26 1968-06-11 Mansei Kogyo Kk Ignition mechanism of liquefied gas fueled lighter
US3384786A (en) * 1965-12-28 1968-05-21 Mansei Kogyo Kk Manually operable piezoelectric gas lighters
US3408153A (en) * 1966-04-25 1968-10-29 Ishiguro Mitsuei Gas lighter with a manually operable piezoelectric ignition device

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3576383A (en) * 1968-08-02 1971-04-27 Ransen Corp Piezoelectric ignition mechanism
US3585417A (en) * 1969-03-06 1971-06-15 Mallory & Co Inc P R Piezoelectric device having a resistor and a plastic insulating casing
US3967141A (en) * 1970-12-01 1976-06-29 Dynamit Nobel Aktiengesellschaft Piezoelectric energy source
US3793561A (en) * 1971-12-23 1974-02-19 Swelex Teknik Ab Piezoelectric gas lighter
FR2211628A1 (es) * 1971-12-23 1974-07-19 Swelex Teknik Ab
US3891381A (en) * 1973-03-31 1975-06-24 Mansei Kogyo Kk Spark ignitable cigarette lighter
US3984738A (en) * 1973-05-14 1976-10-05 Braun Aktiengesellschaft Piezoelectric igniter for lighters
US3949248A (en) * 1973-07-10 1976-04-06 Braun Aktiengesellschaft Piezoelectric igniter using resilient housing
US4025817A (en) * 1974-09-03 1977-05-24 Eastman Kodak Company Trigger device for an electronic flash unit
US3992640A (en) * 1974-11-29 1976-11-16 Eastman Kodak Company Piezo crystal housing and mount
JPS51155173U (es) * 1975-06-03 1976-12-10
JPS52102479U (es) * 1976-01-28 1977-08-03
JPS52105568U (es) * 1976-02-06 1977-08-11
JPS52109980U (es) * 1976-02-17 1977-08-20
JPS52140975U (es) * 1976-04-20 1977-10-25
JPS52168081U (es) * 1976-06-10 1977-12-20
US4315180A (en) * 1976-06-10 1982-02-09 Matsushita Electric Industrial Co., Ltd. High voltage piezoelectric generating device with lengthened spark time
US5262697A (en) * 1991-03-13 1993-11-16 Laforest Bic, S.A. Piezoelectric mechanism for gas lighters
US5798601A (en) * 1995-06-08 1998-08-25 Hansen; James M. Adjustable retrofit ignition kit for portable gas appliances
US5927962A (en) * 1995-12-04 1999-07-27 Laforest Bic, S.A. Piezoelectric mechanism for gas lighters with externally closed telescopic body
US5854530A (en) * 1996-12-18 1998-12-29 Bic Corporation Piezoelectric lighter which has a higher level of difficulty for operation
US6046528A (en) * 1997-11-03 2000-04-04 Bic Corporation Selectively actuatable piezoelectric ignition mechanism
US20230106153A1 (en) * 2021-10-05 2023-04-06 Vpr Brands, Lp Table-top lighters

Also Published As

Publication number Publication date
NL146594B (nl) 1975-07-15
GB1221701A (en) 1971-02-10
FR1552537A (es) 1969-01-03
DE1629890B2 (de) 1973-05-03
DE1629890A1 (de) 1971-03-11
ES350355A1 (es) 1969-04-16
BE710606A (es) 1968-06-17
AT287900B (de) 1971-02-10
NL6801855A (es) 1968-08-12
SE337791B (es) 1971-08-23
CH464832A (de) 1968-11-15

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