Electrical connectors – Having spark or glow plug cover
Reexamination Certificate
1999-11-10
2001-08-14
Paumen, Gary (Department: 2833)
Electrical connectors
Having spark or glow plug cover
C439S126000, C439S127000, C439S271000
Reexamination Certificate
active
06273733
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the construction of a connecting part, or connector, between the ignition plug and the ignition cable in an internal combustion engine, such as an automobile.
2. Description of Background Information
Depending on the layout of the internal combustion engine, such as an engine in an automobile, there may be times in which a heat generating member, e.g., an exhaust pipe or radiator, is positioned very close to the engine body. In fact, the heat which is generated in that area is often greater than 400° C. In such a cases, it is critical that the structure of the connection between the ignition cable and the ignition plug fixed to the engine body take into account the need to provide adequate countermeasures against such heat.
Accordingly, a conventional construction of the connecting part is shown in FIG.
6
and FIG.
7
.
That is to say, the structure of the connecting part is such that a high voltage terminal T of the ignition cable K end is contained in a rubber boot
100
. The rubber boot
100
is engaged with an insulator part Pg of an ignition plug P projecting from the engine body E, by which the high voltage terminal T and the end terminal Pt on the upper part of the insulator Pg are held in an electrically connected state. Additionally, the rubber boot
100
is covered with a metal heat shielding member
110
, thereby preventing thermal degradation of the rubber boot
100
.
Further, since a high voltage may be induced to the heat shielding member
110
by a secondary high voltage which provides the spark to the ignition plug P, the member
110
must be grounded. Therefore, the upper end of an electrically conductive coil spring
112
is engaged at the opening at the bottom end of the heat shielding member
110
. The bottom end of the coil spring
112
projects downwardly from the heat shielding member
110
, so that at the time of engagement of the rubber boot
100
with the insulator Pg, the coil spring
112
is brought into contact with the outer peripheral metal part
114
of the ignition plug P to provide the necessary ground.
However, according to the conventional construction of the connecting part as described above, in engaging the rubber boot
100
with the insulator Pg, the coil spring
112
interferes with the insulator Pg of the ignition plug P. Accordingly, the assembly process is inhibited, and due to the insufficient engagement between the rubber boot
100
and the insulator Pg, electrical connection between the high voltage terminal T and the end terminal Pt becomes imperfect, thus giving rise to a risk of inducing accidental firing of the ignition plug or stoppage of the engine.
Also, because of the configuration of the outside of the rubber boot
100
to be covered by the heat shielding member
110
, the construction of the connecting part must be greater in size. This leads to aggravation of assembly work in a narrow space surrounded by exhaust pipes and the like, and to an imperfect electrical connection between the high voltage terminal T and the end terminal Pt caused by incomplete engagement between the rubber boot
100
and the insulator Pg, which may result in accidental firing of the ignition plug or stoppage of the engine.
Furthermore, according to the construction of the connecting part as above, by pressing downwardly on the upper end of the rubber boot
100
, the rubber boot
100
is to be engaged with the insulator part Pg. However, since the rubber boot per se has low rigidity, and since it is surrounded by a metal heat shielding member
110
, no moderate feel is provided at the time of the engagement. Therefore, assembly is apt to be terminated prior to complete engagement between the rubber boot
100
and the insulator part Pg. Thus, the resulting incomplete electrical connection between the high voltage terminal T and the end terminal Pt gives rise to a risk that the engine will be accidentally fired or stopped.
Accordingly, the present invention has been made to resolve the problems described above, and its object is to provide a construction of the connecting part between the ignition plug and the ignition cable so that it is possible to provide a more secure connection between the connection terminal on the ignition cable side.
SUMMARY OF THE INVENTION
In order to solve the problems as set forth above, a first aspect of the present invention includes a structure for the connection between an ignition plug mounted to the engine body, the ignition plug having an insulator and a terminal projecting from the upper end thereof, and an ignition cable having a high voltage terminal mounted at one end. A ceramic tube is provided having a generally tubular configuration in which the high voltage terminal at the end of the ignition cable can be accommodated. The high voltage terminal is inserted to a predetermined position inside a first end of the plug tube through a first bushing, and a second bushing is provided at a second end. The high voltage terminal and the end terminal are electrically connected in the plug tube by fitting the second bushing over the insulator, and the high voltage terminal is held at a predetermined position in the plug tube by engagement with the first bushing.
In a second aspect of the present invention, the plug tube may be configured to include a projection on the inner peripheral surface of the second end of the plug tube, and a groove for engagement with the projection is formed on the second bushing, so that when the second bushing is inserted into the second end of the plug tube, the projection is engaged with the groove.
Furthermore, according to a third aspect of the present invention, the second bushing may be formed with a configuration and size as to be accommodated within the second end of the plug tube.
In another aspect of the present invention, a connector is provided for connecting an ignition cable to an ignition plug, the ignition plug being mounted to project from an engine body, the plug having an insulator and an end terminal disposed at an upper end of the plug, and the ignition cable having a high voltage terminal at one end thereof. The connector includes a plug tube formed of a ceramic material and having a generally tubular configuration in which a high voltage terminal at the end of the ignition cable can be accommodated, with first and second bushings inserted within first and second ends of the plug tube, respectively. The high voltage terminal is receivable within the plug tube with the first bushing fixedly holding the ignition cable so that the high voltage terminal is located at a predetermined position in the plug tube to engage the end terminal of the ignition plug, and the high voltage terminal and the end terminal are electrically connectable within the plug tube by fitting the second bushing over the insulator such that the high voltage terminal engages the end terminal.
According to a further aspect of the present invention, a connector is provided for connecting an ignition cable to an ignition plug, the ignition plug being mounted to an engine body and having an insulator and an end terminal disposed at an upper end thereof projecting from the engine, and the ignition cable having a high voltage terminal at one end thereof. The connector includes a plug tube formed of an electrically insulating, high heat resistant material and having a generally tubular configuration in which a high voltage terminal at the end of the ignition cable can be accommodated, and first and second bushings are inserted within first and second ends of plug tube, respectively. The high voltage terminal is receivable within the plug tube with the first bushing fixedly holding the ignition cable so that the high voltage terminal is located at a predetermined position in the plug tube to engage the end terminal of the ignition plug, and the high voltage terminal and the end terminal are electrically connectable within the plug tube by fitting the second bushing over the insulator such that the high voltage terminal
Gilman Alexander
Greenblum & Bernstein P.L.C.
Paumen Gary
Sumitomo Wiring Systems Ltd.
LandOfFree
Connecting part for an ignition plug and ignition cable does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Connecting part for an ignition plug and ignition cable, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Connecting part for an ignition plug and ignition cable will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2474464