[001] The present subject matter described herein, relates to a rack and pinion assembly of vehicle having steering gear yoke plunger, and, in particular, to a tool for setting/adjusting the vehicle steering gear yoke/plunger of the rack against/with the pinion of the steering gear assembly. More particularly, the present subject matter relates to a tool to press the yoke to remove a clearance or gap between gears of the pinion and the rack bar, which improves the operation stability of a vehicle, and reduces noise of the vehicle during running condition.
BACKGROUND AND PRIOR ART:
[002] Rack-and-pinion steering systems are well known in the motor vehicles. Rack-and-pinion steering systems include a steering gear assembly with a rack and a pinion wherein the pinion and a toothed portion of the rack form intermeshing gears. A rotational force is applied via a steering wheel on a steering shaft and the pinion is transformed by the steering gear assembly into an axial force of the rack and remitted to steerable wheels of the motor vehicle. Nowadays, the rack-and-pinion steering systems are usually designed as hydraulic, electro-hydraulic or electric power-steering mechanisms supporting a driver during steering operation.
[003] Since considerable forces occur in the steering gear assembly occasionally, it was realized soon that special provisions have to be made in order to keep the rack and the pinion in an engagement substantially free of play or backlash. Otherwise, there is a risk that the rack moves away from the pinion by a deformation transverse to its longitudinal direction when a load is applied. This would lead to an undesirable increasing backlash at least and, in an extreme case, even to a slip in the steering system.
[004] In order to prevent such steering behavior, a support yoke or plunger is usually provided near the pinion, this support yoke provides a pressure force as

constant as possible to urge the rack against the pinion. The greatest challenges for such yoke are firstly the designated pressure force is kept as constant as possible, secondly a compensation of wear due to sliding friction between the support yoke and the rack during steering operation, and finally an avoidance of disturbing rattle noise during motor vehicle operation.
[005] In the regular use of the vehicle, a gap is created between the meshing of teeth between the rack and the pinion which generates rattling noise during vehicle operation. In order to remove this gap, the yoke has to be pressed against the rack with some tool.
[006] Referring to figure 1, in order to remove the gap, the frame assembly 101 is removed from the vehicle and then steering gear assembly 102 is removed from the frame assembly. After removing the steering gear assembly 102 from the frame assembly 101, the yoke 103 in the steering gear assembly 102 is adjusted as per requirement. As shown in the figure 2, the yoke 103 has a lock nut 103a and a rack damper screw 103b which is adjusted with a tool after dis-assembly with the frame of the vehicle. After adjustment of the yoke 103, the steering gear assembly 102 is assembled on the frame assembly 101 and the frame assembly 101 is assembled on the vehicle. The yoke 103 is adjusted using lock nut wrench. The technical problem in the existing art is that the complete process of gap removal by adjusting the yoke takes more than 3 hours and huge manpower cost. Further, re-checking of all parts after assembly take another hour and which increases overall operational cost.
[007] Further, there is no as such tool exist in the art which can remove the gap in assembled condition of the steering gear assembly on the vehicle frame. In some cases, there is a cut under the chassis frame to access the yoke, but it is not feasible in all structures of motor vehicles.
[008] Therefore, there is need in the art to develop a tool which can access the yoke in the steering gear assembly assembled on the vehicle frame and remove the gap between the teeth of the rack and the pinion. The present subject provides a tool for removing the gap between the rack and the pinion by rotating the yoke.

OBJECTS OF THE INVENTION:
[009] The principal objective of the present invention is to remove gap between teeth of rack and pinion in steering gear assembly of a vehicle.
[0010] Another object of the present subject matter is to remove gap between the teeth of rack and pinion in steering gear assembly by rotating yoke or plunger to press the rack against the pinion.
[0011] Another object of the present subject matter is to provide a tool which can adjust the yoke in the rack and pinion assembly in the steering gear assembly.
[0012] Another object of the present subject matter is to provide a tool through which yoke setting/adjustment can be done on vehicle without removing chassis frame and steering gear assembly from the vehicle.
[0013] Yet another object of the present invention is to provide a tool for adjustment of the yoke in the rack and pinion assembly that is simple and inexpensive, and efficiently removes the gap between the meshed teeth of the rack and the pinion.
SUMMARY OF THE INVENTION:
[0014] The subject matter disclosed herein relates to a tool for removing a gap between rack and pinion in steering gear assembly of a vehicle. In the present subject matter, there is no need to dis-assemble the steering gear assembly from the vehicle frame. The present tool has a cylindrical hollow tube component and a screw extension rod component. The cylindrical hollow tube component has an angular dial at one end and a lock nut receiving portion at other end to receive lock nut of the yoke. The screw extension rod component has a polygon shape profile at one end for engagement with rack damper screw and a polygon shape profile at other end for engagement with a needle wrench. Further, a needle wrench is provided to loosen and tighten the rack damper screw during clearance adjustment. The needle wrench has a handle portion at one end and a polygon shape profile receiving portion at other end along with a needle. The polygon shape profile receiving portion receives the polygon shape profile of the screw

extension rod component. The screw extension rod component resides in the cylindrical hollow tube component with help of bearing and circlip. The bearing and circlip provide precise movement of the screw extension rod component inside the cylindrical hollow tube component. The cylindrical hollow tube component is rotated by a wrench to loosen the lock nut of the yoke, and the screw extension rod component is rotated by the needle wrench to adjust the rack damper screw of the yoke to remove the gap between the rack and the pinion.
[0015] In order to further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0017] Fig. 1 illustrates frame and steering gear assembly on vehicle in general art;
[0018] Fig. 2 illustrates yoke in the steering gear assembly in general art;
[0019] Fig. 3 illustrates isometric exploded view of an exemplary embodiment of the tool, in accordance with an embodiment of the present subject matter;
[0020] Fig. 4 illustrates the assembled view of the tool with yoke assembly of fig. 3 in an assembled relationship;

[0021] Fig. 5 illustrates assembled view of the tool of fig. 3 in accordance with an embodiment of the present subject matter;
[0022] Fig. 6 illustrates cross section view along AA of fig. 5; and
[0023] Fig. 7 illustrates the plunger profile, lock nut profile and working end profile of the tool for engagement with the plunger profile and the lock nut profile to tight the yoke/plunger, in accordance with an embodiment of the present subject matter.
[0024] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0025] The subject matter disclosed herein relates to a tool for removing a gap between rack and pinion in steering gear assembly of a vehicle. In the present subject matter, there is no need to dis-assemble the steering gear assembly from the vehicle frame. The present tool has a cylindrical hollow tube component and a screw extension rod component. The cylindrical hollow tube component has an angular dial at one end and a lock nut receiving portion at other end to receive lock nut of the yoke. The screw extension rod component has a polygon shape profile at one end for engagement with rack damper screw and a polygon shape profile at other end for engagement with a needle wrench. Further, a needle wrench is provided to loosen and tighten the rack damper screw during clearance adjustment. The needle wrench has a handle portion at one end and a polygon shape profile receiving portion at other end along with a needle. The polygon shape profile receiving portion receives the polygon shape profile of the screw extension rod component. The screw extension rod component resides in the cylindrical hollow tube component with help of bearing and cir-clip. The bearing and cir-clip provide precise movement of the screw extension rod component

inside the cylindrical hollow tube component. The cylindrical hollow tube component is rotated by a wrench to loosen the lock nut of the yoke, and the screw extension rod component is rotated by the needle wrench to adjust the rack damper screw of the yoke to remove the gap between the rack and the pinion.
[0026] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
[0027] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
[0028] Figure 3 illustrates an un-assembled structure of tool to remove gap between the rack and the pinion in the steering gear assembly, in accordance with an embodiment of the present subject matter. The tool 200 comprises three parts,

i.e., a cylindrical hollow tube component 201, a screw extension rod component 202, and a needle wrench 203. Further, a wrench 204 is required to rotate the tool 200. The cylindrical hollow tube component 201 has an angular dial 201a at one end and a lock nut receiving portion 20Id at other end to receive lock nut 103a of yoke of the steering gear assembly. The lock nut 103a of the yoke 103 is a male nut which engages with the lock nut receiving portion 20Id of the cylindrical hollow tube component 201.
[0029] The screw extension rod component 202 has a polygon shape profile 202a at one end for engagement with rack damper screw 103b of the yoke 103 of the steering gear assembly and a polygon shape profile 202b at other end for engagement with the needle wrench 203. The rack damper screw 103b of the yoke 103 (as shown in the figure 2, 7a and 7b) is a female nut which receives the polygon shape profile 202a of the screw extension rod component 202. The polygon shape profile 202a can be large in size than the polygon shape profile 202b. In reference to the drawings of the present subject matter, the polygon shape profile 202a and the polygon shape profile 202b are hexagon in shape. Further, the polygon shape profile 202a and the polygon shape profile 202b can be of any polygonal shape, such as triangle, rectangle, pentagon, hexagon, or heptagon. Furthermore, the shape of the polygon shape profile 202a depends on receiving profile of the rack damper screw 103b of the yoke 103. On the other hand, shape or profile of the polygon shape profile 202b depends on the receiving profile of the needle wrench 203.
[0030] If male and female profile of the lock nut 103a and the rack damper screw 103b changes, the female and male profile of the cylindrical hollow tube component 201 and the screw extension rod component 202 changes accordingly. Therefore, both the profile and shape of the lock nut and the rack damper screw are in the scope of the present subject matter.
[0031] Assembly of the screw extension rod component 202 and the cylindrical hollow tube component 201 has bearing 201e and a cir-clip 201f for precise rotation of the screw extension rod component 202 inside the cylindrical hollow

tube component 201. After assembly, the screw extension rod component 202 is rotatably mounted in the cylindrical hollow tube component 201 and act as a single component.
[0032] Third component, the needle wrench 203, has a handle portion at one end and a polygon shape profile receiving portion 203b at other end along with a needle 203a. The polygon shape profile receiving portion 203b has an aperture to receive the polygon shape profile 202b of the screw extension rod component 202. The needle 203a extends toward the screw extension rod component 202. The needle wrench 203 has a slot 203d below the polygon shape profile receiving portion 203b to receive the wrench 204. Further, the polygon shape profile receiving portion 203b has screws 203c to tight the needle wrench 203 with the polygon shape profile 202b of the screw extension rod component 202. Upon tightening the screws 203c, a play or gap between the polygon shape profile 202b of the screw extension rod component 202 and the polygon shape profile receiving portion 203b is removed. The screws 203c can be tighten by any L-shape key or screw driver. The screws 203c provide accuracy during the operation of the tool 200. The needle 203a can also be mounted with a screw on the screw extension rod component 202. The needle 203a provides accurate angular rotation of the screw extension rod component 202 inside the cylindrical hollow tube component 201.
[0033] Fourth component in the tool assembly is a wrench 204 which engages with the cylindrical hollow tube component 201 and the needle wrench 203 to rotate them. The cylindrical hollow tube component 201 has a plate 201c connected with the angular dial 201a, the plate has a slot 20lea to receive the wrench 204 for rotating the cylindrical hollow tube component 201. The wrench 204 has a male portion 204a which engages with slot 20lea of the cylindrical hollow tube component 201 and the slot 203 d of the needle wrench 203. Required torque is given to the wrench 204 which rotates the cylindrical hollow tube component 201 and the needle wrench 203 accordingly.

[0034] As shown in the figure 4, the assembled view of the tool 200 as shown in the figure 3 is illustrated. The cylindrical hollow tube component 201 houses the screw extension rod component 202. Once the screw extension rod component 202 resides inside the cylindrical hollow tube component 201, the needle wrench 5 203 engaged with the screw extension rod component 202 with the polygon shape profile receiving portion 203b. The needle wrench 203 rotates the screw extension rod component 202 which is engaged with the rack damper screw of the yoke at other end, i.e., the polygon shape profile 202a.
[0035] Figure 5 illustrates assembled view of the tool, in accordance with an 10 embodiment of the present subject matter. In the assembled tool, the screw extension rod component 202 is rotatably mounted in the cylindrical hollow tube component 201 and receives the needle wrench 203 and the wrench 204. Fig. 6 illustrates cross section AA of the figure 5. Fig. 6 illustrates all components of the tool 200 as illustrated in the figure 3. Figure 7a shows female profile of the rack 15 damper screw 103b and figure 7b shows male profile of the lock nut 103a of the yoke 103. Figure 7c shows the working end profile of the tool 200 having engaging portions 201d and 202a which engage with the lock nut 103a and the rack damper screw 103b.
[0036] Working of the tool to remove the gap between the rack and the pinion in 20 the steering gear assembly.
[0037] When the tool 200 in assembled position engages with the yoke 103 of the steering gear assembly 102, the lock nut receiving portion 201d of the cylindrical hollow tube component 201 engages with the lock nut 103a of the yoke 103. The wrench 204 engages with the slot 201ca to rotate the cylindrical hollow tube 25 component 201 for loosing and tighten the lock nut 103a of the yoke 103. Once the lock nut 103a is loosed, the needle wrench 203 is attached with the polygon shape profile 202b of the screw extension rod component 202 to adjust the rack damper screw 103b of the yoke 103. One end of the screw extension rod component 202 is engaged with the rack damper screw 103b of the yoke 103
10

Therefore, rotation applied on the other end of the screw extension rod component 202 rotates the rack damper screw 103b of the yoke.
[0038] In order to adjust the rack damper screw 103b of the yoke 103, firstly, the needle wrench 203 tighten/torqued the rack damper screw 103b of the yoke 103 5 upto zero clearance/backlash. After tightening the rack damper screw 103b of the yoke 103 upto zero clearance/backlash, the angular rotation is measured for the threshold clearance/backlash or required clearance/backlash and the rack damper screw 103b is loosen upto the measured threshold clearance/backlash by the needle wrench 203 with the help of the needle 203a and the angular dial 201a. The
10 angular dial 201a is given to measure or record angular rotation of the needle wrench 203 with the help of the needle 203a. With the help of the needle 203a of the needle wrench 203 accurate angular rotation can be measured. The angular rotation value of the needle wrench 203 provides angular rotation value of the rack damper screw 103b of the yoke 103. Further, the axial displacement of the
15 rack damper screw 103b is calculated by using the screw pitch value and angular rotation of the needle wrench 203. The axial displacement of the rack damper screw is achieved accurately by the needle 203a and the angular dial 201a. Therefore, angular rotation of the needle wrench 203 can be controlled as per requirement of the gap/clearance between the rack and the pinion by the needle
20 203a and the dial 201a.
[0039] Once the desired tolerance or gap between the rack and the pinion is achieved, locknut 103a torqueing can be done by using wrench 204. While torqueing, the rack damper screw (103b) is held in position by extension rod component (202) using needle wrench (203). Once torqueing is completed, the
25 wrench 204 and the needle wrench 203 are removed from the cylindrical hollow tube component 201 and the screw extension rod component 202, respectively. In the present subject matter, there is no need to dis-assemble the steering gear assembly 102 from the frame assembly 101 of the vehicle. The yoke of the steering gear assembly 102 can be adjusted in vehicle standing position. With the
30 help of the present tool, the yoke can be adjusted within 5-10 minutes as
11

compared to 3-5 hours in previous methods. Further, service cost of the yoke adjustment also reduces drastically.
[0040] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.

We claim:
A tool (200) for adjusting yoke (103) in steering gear assembly (102) of vehicle, the tool (200) comprising:
a cylindrical hollow tube component (201) having an angular dial (201a) at one end and a lock nut receiving portion (20Id) at other end to receive lock nut of the yoke (103);
a screw extension rod component (202) having a polygon shape profile (202a) at one end for engagement with rack damper screw (103b) and a polygon shape profile (202b) at other end; and
a needle wrench (203) has a handle portion at one end and a polygon shape profile receiving portion (203b) at other end along with a needle (203a), wherein the polygon shape profile receiving portion (203b) receives the polygon shape profile (202b) of the screw extension rod component (202), wherein the needle wrench (203) has a slot (203d) below the polygon shape profile receiving portion (203b) to receive a wrench (204) for torqueing the rack damper screw (103b) for zero clearance,
wherein the cylindrical hollow tube component (201) houses the screw extension rod component (202), and
wherein the cylindrical hollow tube component (201) is rotated by the wrench (204) to loosen the lock nut of the yoke (103), and the screw extension rod component (202) adjusts the rack damper screw (103b) of the yoke (103) by the needle wrench (203).
The tool (200) as claimed in claim 1, wherein the needle wrench (203) adjusts the rack damper screw (103b) of the yoke (103) by
first tightening the rack damper screw (103b) of the yoke (103) upto zero clearance; and
loosening the rack damper screw (103b) of the yoke (103) upto threshold clearance by measuring the angle by the needle (203a) on the angular dial (201a).

The tool (200) as claimed in claim 1, wherein the cylindrical hollow tube component (201) has a plate (201c) connected with the angular dial (201a), the plate (201c) has a slot (20lea) to receive the wrench (204) for rotating the cylindrical hollow tube component (201).
The tool (200) as claimed in claim 1, wherein the cylindrical hollow tube component (201) has a bearing (20le) and locking circlip (20If) of the bearing (20le) to ensure precise movement of the screw extension rod component (202) inside the cylindrical hollow tube component (201).
The tool (200) as claimed in claim 1, wherein the clearance of the yoke (103) is measured with combination of the needle (203a) and the angular dial (201a).
The tool (200) as claimed in claim 1, wherein the lock nut is a male nut which engages with the lock nut receiving portion (20Id).
The tool (200) as claimed in claim 1, wherein the rack damper screw (103b) of the yoke (103) is a female nut which receives the polygon shape profile (202a) of the screw extension rod component (202).
The tool (200) as claimed in claim 1, wherein the polygon shape profile (202a) of the screw extension rod component (202) matches with surface of the rack damper screw (103b).
The tool (200) as claimed in claim 1, wherein the angular dial (201a) determines angular rotation of the needle wrench (203).
The tool (200) as claimed in claim 1, wherein the wrench (204) is torque wrench.