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US3783489A Expired / Lapsed US ⏱️ 0.0 years remaining

Apparatus for firing ceramic sparkplug insulators

Assignee: Robert Bosch GmbH
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Filing: 1972-08-10
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Granted: 1974-01-08
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Expires: 1992-08-10
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Abstract

Abstract Apparatus for firing sparkplug insulators comprises a jig having an apertured bottom wall. A pin having a free end and a collar situated adjacent the latter is arranged to move vertically from below the bottom wall through a respective aperture therein. A sleeve slidably mounted on the pin is introduced into the aperture to be expanded therein in response to a further upward movement of the pin beyond the point at which a stop prevents the sleeve from moving upwardly, and thus to center the pin in respect to the aperture. The free end of the pin engages the central hole of an insulator, the extent of penetration into the latter being limited by the collar and the pin with the thus centered insulator is then moved downwardly so as to introduce the insulator into the aperture, while the collar prevents the sleeve from enclosing the free end of the pin.

Inventors

  • 👤 J Duffner

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 22:01
CPC Classifications
F; F27; F27D; F27D5/00; F27D5/005; H; H01; H01T; H01T21/00; H01T21/02; Y; Y10; Y10T; Y10T29/00; Y10T29/53; Y10T29/53978

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 92 words
Apparatus for firing stepped-diameter ceramic spark plug insulators each having a larger diameter section and a smaller diameter section, comprising a jig having a bottom wall provided with a plurality of apertures each adapted to receive and retain the smaller diameter section of a respective insulator to prevent the larger diameter section of said respective insulator from entering therein so that the insulator may rest on said bottom wall while partially inserted into the respective aperture; and engaging means for acquiring and centering a respective insulator during automatic loading of said jig.
Claim 2
Dependent Claim 92 words
Apparatus for firing stepped-diameter ceramic spark plug insulators each having a larger diameter section and a smaller diameter section, comprising a jig having a bottom wall provided with a plurality of apertures each adapted to receive and retain the smaller diameter section of a respective insulator to prevent the larger diameter section of said respective insulator from entering therein so that the insulator may rest on said bottom wall while partially inserted into the respective aperture; and engaging means for acquiring and centering a respective insulator during automatic loading of said jig.
Claim 3
Dependent Claim 11 words
Apparatus as defined in claim 1, wherein said apertures are tapered.
Claim 4
Dependent Claim 54 words
Apparatus as defined in claim 1, wherein the diameter of each aperture in the region where an insulator is to rest on said jig is greater than that of the smaller diameter section of the insulator prior to firing and smaller than that of the larger diameter section of the insulator subsequent to firing.
Claim 5
Dependent Claim 55 words
Apparatus as defined in claim 1, wherein said bottom all has a top surface on which the larger diameter sections rest, and wherein each aperture is banded at said top surface by a rim which acts as a centering means for the positioning of the insulators in said jig during the loading of the latter.
Claim 6
Dependent Claim 144 words
Apparatus as defined in claim 1, each insulator having a central bore, and said bottom wall being normally arranged horizontally while loading said jig with insulators is effected by lowering the latter into the apertures of the jig from above; and wherein said engaging means comprises pin means having a free end dimensioned to mAtingly enter into the central bores of the insulators, said pin means bein arranged to move vertically along the axis of an aperture being filled between a first position wherein said free end is below said bottom wall and a second position wherein said free end has penetrated a respective aperture and extends above said bottom wall; and clamping means cooperating with said pin means and the respective aperture for maintaining said pin means coaxially aligned with the axis of the respective aperture while said pin means are positioned therein.
Claim 7
Dependent Claim 32 words
Apparatus as defined in claim 5, wherein said free end is provided with stop means for limiting the extent of penetration of said free end into the central bore of an insulator.
Claim 8
Dependent Claim 61 words
Apparatus as defined in claim 6, wherein said clamping means comprises expandable sleeve means coaxial with said pin means and enclosing at least a portion of said pin means with freedom of axial movement along the latter, said stop means being operative to limit the movement of said sleeve means above said stop means in a sense enclosing said free end.
Claim 9
Dependent Claim 118 words
Apparatus as defined in claim 6, wherein said sleeve means has inner and outer cylindrical surfaces and a top portion which is expandable in radial direction whereby said outer cylindrical surface only frictionally engages said apertures when said top portion is expanded, said inner surface of said top portion including a tapered section; and further comprising bearing means cooperating with said pin means and said tapered section for expanding said sleeve means in response to upward movement of said pin means relative to said sleeve means beyond a predetermined extent while the insulator is outside of a respective aperture, to thereby maintain coaxial alignment of said pin means at least until the insulator is inserted into said aperture.
Claim 10
Dependent Claim 48 words
Apparatus as defined in claim 8, wherein said bearing means comprises an annular tapered bushing coaxially mounted for slidable movement on said pin means; and further comprising biasing means cooperating with said pin means to urge said bushing against said tapered section to thereby expand said sleeve means.
Claim 11
Dependent Claim 59 words
Apparatus as defined in claim 8, wherein said sleeve means extends axially below said bottom wall and is provided with a bearing surface below said bottom wall, and further comprising another stop means for engaging said bearing surface to limit the upward travel of said sleeve means to thereby permit engagement of said bearing means and said tapered section.
Claim 12
Dependent Claim 32 words
Apparatus as defined in claim 10, further comprising biassing means cooperating with said pin means and said sleeve means for urging the latter in an upward direction relative to said pin means.

References Cited (Backward Citations)

US3667103A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-01-07 1977-07-09 1978-01-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-01-07 1981-07-09 1982-01-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-01-07 1985-07-09 1986-01-08 $7700.00 Window Closed / Lapsed

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