US3903436A - Piezoelectric generating device - Google Patents

Abstract

A piezoelectric generating device in which a hammer is supported within an outer case through a pair of hammer cams rotatably arranged on the hammer. The hammer will thus impart a blow against a piezoelectric element unit by the operation of a manipulator.

Description

United States Patent Mariya Sept. 2, 1975 [54] PIEZOELECTRIC GENERATING DEVICE [56] References Cited [75] Inventor: Nobuyoshi Moriya, Urawa, Japan NITED STATES PATENTS [73] Assignee: Mansei Kogyo Kabushiki Kaisha, g E Japan 3,793,561 2 1974 Lundh 310/87 x [22] Filed: Feb. 20, 1974 Primarv Examiner-Mark O. Budd 3 [7]] Appl' 444132 Allorney, Agent, or Firm-Armstrong, Nikaido &

Wegner [30] Foreign Application Priority Data Mar. 2, 1973 Japan 4324072 11 [57] ABSTRACT 1973 Japan 48'26928w] A piezoelectric generating device in which a hammer is supported within an outer case through a pair of 52 us. (:1 310/s.7; 317/1310. 11 hammer Cams rotatably arranged on the hammer. The [5 t t hammer h i p a blow against a piezoelectric [58] Field of Search 310/83, 847, 9.1; 317/81, element unit by the Operation of a manipulator 317/96, DIG. ll; 43l/l43, 255

18 Claims, 7 Drawing Figures PIEZOELECTRIC GENERATING DEVICE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is related to a piezoelectric generating device of ignition apparatus, and more particularly to an improved piezoelectric generating device which is used for gas stoves, gas cookers, cigarette gas lighters or the like.

2. Brief Description of the Prior Art I-Ieretofore various piezoelectric generating devices have been disclosed. For example, US. Pat. No. 3,509,388 shows a high voltage generating device including a piezoelectric element, a hammer for striking the piezoelectric element, an accumulating spring for storing the energy required to drive the hammer toward the piezoelectric element and a manipulator for controlling the hammer. According to the teachings of the US. Patent, the accumulating spring is interposed with torsion between the manipulator and the hammer, and one end of the spring is fixedly secured on the top end of the hammer to rotate the hammer so that the hammer rests spaced from the piezoelectric element. Therefore this structure requires much skill in assembling the device and in replacing its parts with new ones when some parts of the device are damaged. Further, the interposed accumulating springs shall be stressed and simultaneously twisted so as to drive the hammer toward the piezoelectric element. Accordingly the accumulating spring and its parts operatively connected therewith are susceptible to be damaged due to repeatedly continuous operations of the generating device.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved piezoelectric generating device which is easily assembled or repaired.

Another object of the present invention is to provide an improved piezoelectric generating device which is durable against continuous operations.

These and other objects and advantages of the invention may be easily ascertained by referring to the following description and appended drawings in which:

FIG. 1 is an elevational view of the inoperative position of the piezoelectric generating device according to the present invention;

FIG. 2 is an elevational view in section showing the inoperative position of the piezoelectric generating device shown in FIG. 1;

FIG. 3 is an elevational view in section showing the operative position of the piezoelectric generating device shown in FIGS. 1 and 2;

FIG. 4 is an enlarged perspective view showing a hammer and a pair of hammer cams of the piezoelectric generating device shown in FIGS. 1 to 3;

FIGS. 5, 6 and 7 show another embodiment of a piezoelectric generating device according to the present invention, FIG. 5 being an elevational view, FIG. 6 being an elevational view in section and FIG. 7 being an enlarged perspective view.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1 to 4, an outer case 1 has a conventionalpiezoelectric element unit 2 fixedly secured on the bottom thereof and amanipulator 3 is slidably held within the outer case 1 by a pair ofhammer cams 4 under the upward influence of areturn spring 5 arranged between themanipulator 3 and thepiezoelectric element unit 2.

Ahammer 6 is maintained spaced from thepiezoelectric element unit 2 by the pair ofhammer cams 4 which are rotatably arranged in atransverse opening 8 of thehammer 6. Thistransverse opening 8 is formed beside the central axis of thehammer 6 to provide space for thecams 4.

Eachhammer cam 4 has afirst arm 4a which is in operative connection with themanipulator 3 and asecond arm 4b which acts to limit the movement of thehammer cam 4 in such a manner hereinafter described. Thefirst arm 4a is designed to extend horizontally in its inoperative position of thehammer cam 4 to engage aprojection 9 of anopening 10 formed on the side wall of themanipulator 3. Thisprojection 9 acts as restoring means for thehammer cam 4 to lift thehammer cam 4 to its initial upward position. The second arm 41) has acutout portion 4b which is designed to engage a retainingportion 11 of a guidingslot 12 formed on the outer case 1 so as to limit the upward and rotational movements of thehammer cam 4.

The guidingslot 12 which acts as guiding means for thehammer cam 4 has ahorizontal portion 12a which is wider than thefirst arm 4a of thehammer cam 4 for the purposes hereinafter described. The guidingslot 12 has further a guidingportion 12b which extends longitudinally to direct the upward and downward movements of thehammer cam 4. The above-mentionedretaining portion 11 is formed in the guidingportion 12b, and below the retainingportion 11 there is formed a sliding seat 11a which is adapted to maintain thesecond arm 4b of thehammer cam 4 while anenergy accumulating spring 7 stores a predetermined striking energy therein upon depression of themanipulator 3. A sufficient space is provided between theretaining portion 11 and the sliding seat 11a for the rotation of thesecond arm 4b of thehammer cam 4.

Thehorizontal portion 12 is formed to facilitate the arrangement or replacement of thehammer cam 4 in thetransverse opening 8 of thehammer 6. After thehammer 6 is installed with theenergy accumulating spring 7 within themanipulator 3, thehammer cam 4 is placed through the guiding slot I2 formed on the outer case 1 and theopening 10 formed on themanipulator 3 by slightly raising thehammer 6 with a tool or the like. For the purposes, athrough bore 40 is provided on one of thehammer cams 4. When thehammer cams 4 are required to be replaced due to damage, for instance, they may be easily taken out of thehammer 6 by pushing theopposite hammer cam 4 with a fine pin or the like, after the coincidental adjustment is made to register the positional relation between the hammer and the horizontal portion of the guidingslot 12. In the normal position of thehammer 6, thefirst arm 40 of eachhammer cam 4 is positioned within the outer case 1 and kept in its position by the side wall of the outer case 1.

Upon depressing themanipulator 3 against the action of theenergy accumulating spring 7, the striking energy is st aed in the accumulatingspring 7 while thesecond arm 4b of thehammer cam 4 comes into contact with the sliding seat 11a formed in the guidingslot 12 to maintain thehammer 6 in spaced relationship with thepiezoelectric element unit 2. When the predetermined striking energy is stored in the accumulatingspring 7, the upperhorizontal end 10a of theopening 10 is brought into engagement with thefirst arm 4a of thehammer pin 4 to rotate thehammer cam 4 in the counterclockwise direction in thetransverse opening 8 of thehammer 6. This counterclockwise rotation of thehammer cam 4 causes thesecond arm 4b to disengage from the sliding seat 11a and thehammer 6 is rapidly driven under the action of the accumulatingspring 7 to impact a blow against thepiezoelectric element unit 2.

Thehammer 6 returns to its initial position by the action of the return spring together with themanipulator 3 through thehammer cam 4 arranged on thehammer 6. In the upward movement of themanipulator 3, theprojection 9 of theopening 10 comes into contact with the end portion of thefirst arm 4a of thehammer cam 4 and lifts thehammer cam 4 with thehammer 6, while thesecond arm 4b is also raised along the guidingportion 12b of the guidingslot 12 until thecutout portion 4b engages the retaining portion 1 1 of theguiding slot 12. This engagement of thesecond arm 4b with the retainingportion 11 is effected by the rotation of thehammer cam 4 toward the sliding seat 11a in theguiding slot 12 and themanipulator 3 is held by this engagement in its inoperative position.

The second embodiment, illustrated in FIGS. 5, 6 and 7, comprises anouter case 101 which is provided with a pair of longitudinal guidingslots 102 in the upper section thereof. The pair of guidingslots 102 are diametrically opposed and eachslot 102 has a retaining portion 103 and a slidingseat 103a which is formed below the retaining portion 103. Amanipulator 104 is arranged in telescopic relationship with theouter case 101 and formed withrectangular openings 104a. The rectangular openings are also diametrically opposed and are provided with ahorizontal end 104b and a replacement end 1046 to operate a pair ofhammer cams 105 with firstandsecond arms 105a and 1051; by which ahammer 6 is kept in spaced relationship with apiezoelectric element unit 2 fixedly secured on the bottom of theouter case 101. Between the pair ofhammer cams 105 there is provided a restoringspring 106 which is adapted to rotate thehammer cams 105 to their initial inoperative position. Both ends of the restoringspring 106 are engaged in respective notches 1056 of thehammer cams 105 arranged in atransverse opening 8 of thehammer 6.

Anenergy accumulating spring 7 is interposed between themanipulator 104 and the head portion of thehammer 6, and areturn spring 5 is between the lower end of themanipulator 104 and the shoulder portion of thepiezoelectric element unit 2 which is provided with a lead wire 2a.

Upon depressing themanipulator 104, thesecond arm 105b of thehammer cam 105 engages the slidingseat 103a of the longitudinal guidingslot 102 and theenergy accumulating spring 7 stores energy which drives thehammer 6 toward thepiezoelectric element unit 2 to impart a blow against the latter. When the upperhorizontal end 104b of therectangular opening 104a comes into contact with the first arm 1050 of therotatable hammer cam 105, thehammer cam 105 rotates in the counterclockwise direction to disengage from the slidingseat 103a and thehammer 6 is rapidly propelled by the energy stored in the accumulatingspring 7.

Thehammer 6 is returned by the action of thereturn spring 5 and is maintained in its initial position by the hammer cam arranged on thehammer 6. At first, themanipulator 104 is moved upward by the action of thereturn spring 5, and then in the upward movement of themanipulator 7 of the replacement end 1046' of therectangular opening 104a engages the lower end of thesecond arm 105b to raise thehammer 6 along theguiding slot 102. On the predetermined path of the upward movement, thehammer cam 105 is rotated toward the retaining portion 103 of the guidingslot 102 by the restoringspring 106 to engage the retaining portion 103. In this way, themanipulator 104 and thehammer 6 take their intial positions and both are held by thehammer cam 105 for further action.

While there has been described preferred embodiments of the invention, obviously modifications and variations are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

I claim:

1. A piezoelectric generating device comprising:

a case;

a piezoelectric element unit;

a hammer;

a hammer cam mounted on said hammer and being rotatable between first and second positions to control said hammer;

said hammer cam including first and second arms thereon; an energy accumulating spring for storing energy to drive said hammer toward said piezoelectric element unit;

a manipulator means moveable in relation with said case to stress said energy accumulating spring and to rotate said hammer cam between its first and second position;

guide means formed on said case and adapted to direct the movement of said hammer cam;

said guide means including a retaining means for engaging said second arm of said hammer cam to limit the rotational movement of said hammer cam;

said guide means further including a sliding seat means for engaging said second arm of said hammer cam to maintain said hammer spaced from said piezoelectric element unit while said manipulator moves to store the energy in said energy accumulating spring, wherein when said manipulator rotates said hammer cam to its second position, said second arm is disengaged from said sliding seat whereby said hammer is rapidly driven toward said piezoelectric element unit by the energy stored in said spring.

2. A piezoelectric generating device according to claim 1, wherein said sliding seat is formed between said retaining portion of said guide means and said piezoelectric element unit.

3. A piezoelectric generating device according toclaim 2, wherein said sliding seat has a surface slanting toward said piezoelectric element unit.

4. A piezoelectric generating device according toclaim 3, wherein said guide means includes a longitudinal slot formed in said case extending toward said piezoelectric element unit, wherein said retaining portion and said sliding seat control the movement said hammer cam.

5. A piezoelectric generating device according toclaim 4, wherein space is provided between said retaining portion and said sliding seat for the rotational movement of said second arm of said hammer cam.

6. A piezoelectric generating device according toclaim 5, wherein said second arm of said hammer cam includes an extension on one side thereof, said extension adapted to engage said retaining portion said guideing means.

7. A piezoelectric generating device according toclaim 6, wherein said guide means has a horizontal slot extending laterally from said longitudinal slot for mounting said hammer cam on said hammer.

8. A piezoelectric generating device according toclaim 7, wherein said horizontal slot is formed on the same side as said retaining portion of said guide means.

9. A piezoelectric generating device according toclaim 6, wherein said hammer includes a transverse opening formed therethrough said transverse opening adapted to accomodate a hammer cam on each end thereof, and wherein said guide means is formed on opposite sides of said case.

10. A piezoelectric generating device according toclaim 9, wherein said restoring means is arranged between said hammer cams to bring said second arms into engagement with said retaining portions of said guide means.

11. A piezoelectric generating device according toclaim 10, wherein said restoring means is a coiled spring the opposed ends of which are respectively engaged with the inner sides of said hammer cams within said transverse opening.

12. A piezoelectric generating device according toclaim 9, wherein a through bore is formed on one of said hammer earns.

13. A piezoelectric generating device according toclaim 9, wherein said manipulator includes a pair of rectangular openings on the opposite side walls thereof. said rectangular openings each having an upper end adapted to engage said first arm of said hammer cams.

14. A piezoelectric generating device according to claim 13, wherein said pair of rectangular openings have respectively a projection inwardly extending to engage said first arm of said hammer cams to lift said hammer.

15. A piezoelectric generating device according to claim 13, wherein said rectangular opening has a lower end adapted to engage the lower end portion of said second arm of said hammer cam to lift said hammer when said hammer cam returns from the second position to the first position.

16. A piezoelectric generating device according toclaim 10, wherein said transverse opening is formed on the central axis of said hammer.

17. a piezoelectric generating device according toclaim 10, wherein said transverse opening is formed beside the central axis of said hammer.

18. A piezoelectric generating device according to claim 1 1, wherein each inner end of said hammer cams has a notch therein which engages the end of said coiled spring.

Claims (18)

1. A piezoelectric generating device comprising: a case; a piezoelectric element unit; a hammer; a hammer cam mounted on said hammer and being rotatable between first and second positions to control said hammer; said hammer cam including first and second arms thereon; an energy accumulating spring for storing energy to drive said hammer toward said piezoelectric element unit; a manipulator means moveable in relation with said case to stress said energy accumulating spring and to rotate said hammer cam between its first and second position; guide means formed on said case and adapted to direct the movement of said hammer cam; said guide means including a retaining means for engaging said second arm of said hammer cam to limit the rotational movement of said hammer cam; said guide means further including a sliding seat means for engaging said second arm of said hammer cam to maintain said hammer spaced from said piezoelectric element unit while said manipulator moves to store the energy in said energy accumulating spring, wherein when said manipulator rotates said hammer cam to its second position, said second arm is disengaged from said sliding seat whereby said hammer is rapidly driven toward said piezoelectric element unit by the energy stored in said spring.

2. A piezoelectric generating device according to claim 1, wherein said sliding seat is formed between said retaining portion of said guide means and said piezoelectric element unit.

3. A piezoelectric generating device according to claim 2, wherein said sliding seat has a surface slanting toward said piezoelectric element unit.

4. A piezoelectric generating device according to claim 3, wherein said guide means includes a longitudinal slot formed in said case extending toward said piezoelectric element unit, wherein said retaining portion and said sliding seat control the movement said hammer cam.

5. A piezoelectric generating device according to claim 4, wherein space is provided between said retaining portion and said sliding seat for the rotational movement of said second arm of said hammer cam.

6. A piezoelectric generating device according to claim 5, wherein said second arm of said hammer cam includes an extension on one side thereof, said extension adapted to engage said retaining portion said guideing means.

7. A piezoelectric generating device according to claim 6, wherein said guide means has a horizontal slot extending laterally from said longitudinal slot for mounting said hammer cam on said hammer.

8. A piezoelectric generating device according to claim 7, wherein said horizontal slot is formed on the same side as said retaining portion of said guide means.

9. A piezoelectric generating device according to claim 6, wherein said hammer includes a transverse opening formed therethrough said transverse opening adapted to accomodate a hammer cam on each end thereof, and wherein said guide means is formed on opposite sides of said case.

10. A piezoelectric generating device according to claim 9, wherein said restoring means is arranged between said hammer cams to bring said second arms into engagement with said retaining portions of said guide means.

11. A piezoelectric generating device according to claim 10, wherein said restoring means is a coiled spring the opposed ends of which are respectively engaged with the inner sides of said hammer cams within said transverse opening.

12. A piezoelectric generating device according to claim 9, wherein a through bore is formed on one of said hammer cams.

13. A piezoelectric generating device according to claim 9, wherein said manipulator includes a pair of rectangular openings on the opposite side walls thereof, said rectangular openings each having an upper end adapted to engage said first arm of said hammer cams.

14. A piezoelectric generating device according to claim 13, wherein said pair of rectangular opEnings have respectively a projection inwardly extending to engage said first arm of said hammer cams to lift said hammer.

15. A piezoelectric generating device according to claim 13, wherein said rectangular opening has a lower end adapted to engage the lower end portion of said second arm of said hammer cam to lift said hammer when said hammer cam returns from the second position to the first position.

16. A piezoelectric generating device according to claim 10, wherein said transverse opening is formed on the central axis of said hammer.

17. a piezoelectric generating device according to claim 10, wherein said transverse opening is formed beside the central axis of said hammer.

18. A piezoelectric generating device according to claim 11, wherein each inner end of said hammer cams has a notch therein which engages the end of said coiled spring.

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