Tensioner

Details Tensioner Tensioner

2000-11-22

2003-12-23

Charles, Marcus (Department: 3682)

Endless belt power transmission systems or components

Means for adjusting belt tension or for shifting belt,...

Load responsive tension adjuster or shifter

C474S101000, C474S138000

Reexamination Certificate

active

06666785

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tensioner that gives an appropriate tension to a timing chain or a timing belt of an engine.
2. Description of the Related Art
Of a tensioner that gives an appropriate tension to a timing chain or a timing belt of an engine, there is a type that gives a thrusting force to a plunger by using a compression coil spring. The tensioner of this type is comprised of a body having a hollow cylindrical part formed therein, a plunger engaged in one end of the hollow cylindrical part for sliding movement relative to the body, a plug screwed into the other end of the hollow cylindrical part, and a coil spring disposed between the plunger and the plug in an compressed condition.
In assembling the tensioner, the plunger is held in position against movement in a projecting direction by a pin, and the coil spring is then loaded inside the body. Thereafter, the plug is screwed into the body. When the plug is screwed, the coil spring is compressed, whereby the plunger is given a thrusting force.
However, in the conventional tensioner, the direction of the plug being screwed has been the same as the winding direction of the coil spring. For example, a right-winding coil spring has been used to a plug with a right handed screw, or a left winding coil spring has been used to a plug with a left handed screw.
When the plug and the coil spring are constructed in such a relation, as shown in detail in
FIG. 3
, and a plug
34
is screwed in to compress a coil spring
36
, the plug
34
is caught on a coil edge
38
. Accordingly, the assembling workability is extremely deteriorated. In addition, a buckling is likely to occur on the coil, resulting in a fracture of the coil spring
36
. On the other hand, when the plug
34
is screwed, and the coil spring
36
turns with the rotation of the plug
34
, there occurs the same phenomenon on the plunger side.
Further, when the plug
34
is screwed, the coil edge slides on the plug
34
or on the plunger under a high pressing-frictional force, which produces powders by abrasion. If the powders by abrasion come in on the sliding surface between the body and the plunger, a problem will occur that the plunger does not thrust outward when needed, or the friction on the sliding surface causes the plunger to vibrate, thus generating noises.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to solve the foregoing problems associated with the prior art.
According to the present invention, there is provided a tensioner comprising: a body having a hollow cylindrical part formed therein; a plunger slidably engaged in one end of the hollow cylindrical part for sliding movement relative to the body; a plug screwed into the other end of the hollow cylindrical part of the body; and a coil spring disposed between the plunger and the plug for biasing the plunger in a direction away the plug, wherein a direction of the plug being screwed and a winding direction of the coil spring are different from each other.
When the plug is screwed in, the coil spring is gradually compressed to be strongly pressured to the plug and the plunger. In this instance, since the direction of the plug being screwed and the winding direction of the coil spring are made reverse, there do not occur virtually any catching phenomenon, and the buckling on the coil can be avoided. Therefore, the coil spring will not be broken, and the powders by abrasion will not be produced, which prevents the functional deterioration of the tensioner.


REFERENCES:
patent: 3574418 (1971-04-01), Okabe
patent: 4300890 (1981-11-01), Hallmann et al.
patent: 4708696 (1987-11-01), Kimura et al.
patent: 4995854 (1991-02-01), Ojima
patent: 5030170 (1991-07-01), Ojima
patent: 5073158 (1991-12-01), Ojima
patent: 5637047 (1997-06-01), Schulze
patent: 5871441 (1999-02-01), Ishiguro et al.
patent: 5913742 (1999-06-01), Nakamura et al.
patent: 1 650 669 (1970-10-01), None
patent: 0 212 119 (1990-09-01), None
patent: 1.035.900 (1953-09-01), None

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