FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
1. TITLE OF THE lNVENTION
LOCKING MEANS FOR STOPPER
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. Taiuka Khed.
! District Pune. Pin Code-410501.State
i
: Maharashtra. Country India.

TECHNICAL FIELD
[00.1] 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] In internal combustion engines, transmission member such as a chain/cam chain is used for transmitting rotation from a crankshaft to one or more valve-operating the camshafts. During transmitting the rotation from the driving shaft to a driven shaft i.e. from the crankshaft to one or more valve-operating the camshafts, the chain/cam chain elongates due to the effect of thermal expansion and results into slackening of chain and the like. In order to maintain the tension (lightness) of the chain and/or to overcome the slackening, the use of tensioner is known in the prior art. The tensioner is placed in proximity to the chain within the engine which applies force on the chain in order to tighten the same.
[004] In general, the tensioner includes a plunger, a spring and a rotary shaft arranged inside the tensioner body. For providing load to the belt or the chain, the rotary shaft is energized by spring force which makes plunger to advance in forward direction.
[005] However, since such tensioner is energized by a spring, there are the chances of unexpected advancement of the plunger and projecting it out from the body of the tensioner before its installation on the vehicle as well as it is also to take into consideration at time of uninstallina the tensioner from the vehicle.

[006] For this purpose, the tensioner is provided with a stopper and locking means for stopper in the body which locks the advancement of the plunger. [007] It is an object of the present invention to overcome the shortcomings described in the prior art.
DISCLOSURE OF THE INVENTION
[008] 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.
[009] 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.
[010] 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.
[011] 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.
[012] The cylindrical body has a hole of small diameter formed at the bottom of the body. Slots are created in the hole or on the body where the number of slots formed are at least 2. Slots formed possess a depth of minimum 1 mm. Slots act as locking means for the stopper which holds the tensioner in an inoperative condition.
BRIEF DESCRIPTION OF DRAWINGS
[013] Fig.l shows a section view of the tensioner.
[014] Fig.2 shows the slits formed in the tensioner body.
[015] Fig.3 shows an in-operative condition of the tensioner.
DESCRIPTION OF DRAWINGS
[016] Figure 1 shows a tensioner consisting of screw 1. locking nut 2, 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.
[017] Figure 2 illustrates the slots 12 formed at the bottom of the tensioner body. At least two slots 12 are formed in the body 3. Slots 12. are formed circumferentialiy across a hole of small diameter formed at the bottom of the tensioner body 3. Slots are formed at a minimum depth of 1 mm.

[01 8] Figure 3 shows an in-operative condition of the tensioner. The screw 1 engaged with the locking nut 2 is rotated with the help of stopper 11. The stopper 11 is used to retract the nut 2. The stopper 11 is engaged in the slots 12 -provided in the body 3 to restrict the advancement of the screw 2.

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 screw7 in an inoperative condition, and
a bearing.
wherein the body adapted to mount in proximity of transmission media
consists of locking means for stopper.
2. A tensioner as claimed in Claim 1. wherein the locking means for stopper 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 as claimed in Claim 1. wherein the slot provided possesses a depth of at least 1 mm.