FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
1. TITLE OF THE INVENTION
LOCKING MEANS IN TENSIONER BODY
2. APPLICANT
(a)NAME: ADVIK HI-TECH PVT LTD
(b)NATIONALITY: Indian Company
Plot No. B-5, Chakan Industrial Area,
(c)ADDRESS:
Phase II, Village Vasuli, Taluka Klied,
District Pune, Pin Code-410501,State Maharashtra, Country India.

TECHNICAL FIELD
[001] The present invention relates to a tensioner that imparts a predetermined tensile force to a force transmitting member such as a chain or timing belt that drives a camshaft of an engine mounted in a vehicle for e.g. four wheeler automobile or a two wheeled vehicle.
BACKGROUND ART
[002] A tensioner works to maintain constant tension of a timing chain or timing belt used for an engine of an automobile by pushing the timing chain or belt with a predetermined force if the chain or timing belt becomes loose or slack.
[003] A conventional tensioner consists of a body, screw, nut, bearing, O-ring, Stopper, cap, spring and circlip. Tensioner body has cylindrical portions extending on both sides from the flange. Also tensioner body has slit extending from the flange to the cylindrical portion. Screw has a slit formed in its head. Spring used has its one end placed in the slit of the screw and other end placed in the slit provided in the body. Screw is threadedly engaged with the nut. Stopper is used to provide rotary motion to the screw. Rotary motion of the screw forces the spring to rotate as well. Thereby elastic energy is stored in the spring. Upon removal of the stopper from the screw, the stored elastic energy in the spring rotates the screw.
[004] So the problem existing with such tensioners do not have adequate provision in the body for locking the bearing.
[005] It is an object of the present invention to overcome the shortcomings describe in the prior art.

DISCLOSURE OF THE INVENTION
[006] According to the present invention, there is provided a tensioner which contains a screw, nut, body, spring, bearing with locking feature, thrust member, pin, circlip, cap. o-ring, and stopper. Screw provided has a slit formed in its head. Screw has external threads which engages with the internal threads of the nut. One end of the spring is engaged in the slit provide in the screw while other end of the spring is engaged in the slot provided in the body. Thrust member is placed below the end face of the screw. Cap is fitted on the nut with the help of pin. O- ring is placed in the groove provided in the body. Circlip holds the bearing placed on the body.
[007] Nut provided in the tensioner has across flat portion. The length of the across flat portion depends upon the stroke required. Across flat portion provided on the nut has a projection at its base. The projection at the base of the across flat portion is perpendicular to the across flat portion.
[008] Bearing is a cylinder having particular length. Bearing has steps provided that extend outwards from the top of the cylindrical portion. Minimum steps provided on the bearing are 2. Bearing has projection that extend from the inside of the bearing. The projection provided on the inside of the bearing restricts the movement of the nut by locking the projection extending from the base of the across flat portion.
[009] The cylindrical body extends in an either direction perpendicular to the flange.
The cylindrical body has slots created at the top of the body. At least 2 slots are created in the body. The slots created in the body allow the steps provided on the bearings to rest on it. Moreover, the body has grooves cut across its circumference below the top portion of the body. Circlip is inserted in the groove provided on the body. The step provided on the bearing fits in the slot provided in the body while the circlip which is pre-tensed passes through the step provided on the bearing and

the grooves formed in the body. Hence, the circlip which is pre-tensed holds the bearing tightly.
BRIEF DESCRIPTION OF DRAWINGS
[010] Fig.l shows a section view of the tensioner.
[Oil] Fig.2 shows a sectional view of the bearing.
[012] Fig.3 shows a sectional view of the body.
[013] Fig. 4 shows assembled sectional view of the tensioner assembly.
DESCRIPTION OF DRAWINGS
[014] Figure 1 shows a tensioner consisting of screw 1, locking nut 25 body 3, spring 4, bearing 5, thrust member 6, pin 7, circlip 8, cap 9, o-ring 10, and stopper 11. Screw 1 provided has a slit formed in its head. Screw 1 has external threads which engages with the internal threads of the locking nut 2. One end of the spring 4 is engaged in the slit provide in the screw 1 while other end of the spring 4 is engaged in the slot provided in the body. Thrust member 6 is placed below the end face of the screw 1. Cap 9 is fitted on the nut with the help of pin 7. O- ring 10 is placed in the groove provided in the body. Circlip 8 holds the bearing 5 placed on the body 3.
[015] Figure 2 shows a sectional view of the bearing. Bearing 5 made up of plastic. Bearing 5 is a cylindrical member whose both ends are open. Top portion of the bearing 5 contains stepped portions 12 as described in the figure. At least two stepped portions 12 are provided on the top surface of the bearing 5. The stepped portions 12 provided on the bearing 5 fit in the slots. The stepped portions 12 provided on the bearing 5 project radially outward from the bearing 5.
[016] Figure 3 shows a sectional view of the tensioner body 3. The isometric view clearly shows the slots provided in the tensioner body 3 for engagement of bearing 5. The number of slots provided in the body 3 may vary according to the

number of steps provided on the bearing 5. At least 2 slots will be formed in the body 3.
Figure also illustrates grooves 14 formed in the body circumferentially to place circlip 9.
[017] Figure 4 shows a sectional assembled view of the tensioner. Figure illustrates resting of the stepped portions 12 of the bearing 5 in the slots 13 provided in the body and the stepped portions 12 of the bearing 5 being held tightly by the pre-tensed circlip 8.

CLAIMS
1. A tensioner for an endless driving elements, comprising:
a body adapted to mount in proximity of transmission media;
a locking nut adapted to slide-ably project out from the opening of the body;
a screw adapted to guide the nut which is configured to rotate and deliver axial
motion to nut;
a spring acting between the body and the screw to urge the nut in a direction to
project out from the opening,
a stopper adapted to remove-ably insert in the slit formed in the screw to lock the
screw in an inoperative condition,
a bearing,
wherein the body adapted to mount in proximity of transmission media consists of
locking means for bearing.
2.A tensioner as claimed in Claim 1, wherein the locking means for bearing are in the form of slots provided in the body.
3.A tensioner as claimed in Claim 1, wherein the number of slots formed are at least 2.
4.A tensioner for an endless driving elements, comprising:
a body adapted to mount in proximity of transmission media;
a locking nut adapted to slide-ably project out from the opening of the body;
a screw adapted to guide the nut which is configured to rotate and deliver axial
motion to nut;
a spring acting between the body and the screw to urge the nut in a direction to
project out from the opening,
a stopper adapted to remove-ably insert in the slit formed in the screw to lock the
screw in an inoperative condition, and
a bearing,
wherein the body adapted to mount in proximity of transmission media consists of
locking means for bearing.

5. A tensioner as claimed in Claim 4. wherein the locking means formed on the body consists of circumferential grooves.