A SEALING ASSEMBLY

FIELD OF THE INVENTION

[0001] The present invention relates generally to a sealing assembly and more particularly, but not exclusively, to a sealing assembly for a steering tube assembly for an automotive vehicle.

BACKGROUND OF THE INVENTION

[0002] An automotive vehicle, more specifically a three wheeled motor vehicle is a significant mode of public transportation in many countries of the world. It is vastly used as a passenger carrier providing point to point mode of transpon in rural and urban áreas and offering last mile connectivity, and also for load carrying applications. The vehicle comprises of a steering system in the front portion having a single steering tube received within a head tube.

[0003] FIG. 2 shows a sectional view of the steering system of such three wheeled vehicle according to the prior, art. The conventional steering system comprises a steering tube 52 rotatably engaged with a head tube 51 through a steering cage assembly. The steering tube connects a front wheel of the vehicle to a handle bar. The steering tube allows the driver to make the vehicle follow a desired path and is designed in such a way that the single front wheel is exactly in line with the vehicle centreline. The steering tube 52 comprises of a groove cutout 53 and further maintains a clearance with the head tube 51 to enable its rotation within the head tube 51. Each endportion of the head tube 51 is provided with the steering cage assembly helping in the rotation of the steering tube 52. In an embodiment, an upper steering cage assembly 62 is operatively eñgaged at an upper endportioh of the head tube 51 adjoining the groove cutout 53 and a lower steering cage assembly 61 is operatively engaged at a lower endportion of the head tube 51.

[0004] Such vehicle is generally operated intermittently for 12 to 14 hours a day to enable the driver to maximize his earnings. During the vehicle run in India and other developing countries, the vehicle gets dirty. This is due to dusty and smoky terrain in most Indian cities and also because of the largely unmetalled roads connecting villages to the cities. Thus, lot of undesirable foreign matter including dust enters the steering cage assembly and over a period of time, restricts the smooth rotation of the steering tube 52.
[0005] Further, owing to heavy use and terrain conditions, such vehicle is ajso serviced frequently with use of forced or pressurized water. In an iristance, the water thrown at the steering system percolates downwardly (as shown by the arrows) along the groove cutout 53 towards the steering cage assembly disposed at the upper or lower endportion of the head tube. The failure of water to drain leads to its accumulation in the steering cage assembly which further leads to rusting causing premature failure of the steering cage assembly. The water weakens the greasing of the steering cage aseembly causing an increase in the steering effort. All these things put together affect smooth operation, functionality and durability of the steering system.

SUMMARY OF THE INVENTION

[0006] A need for effective sealing against water and dust is required for the steering cage assembly. Further, the sealing should be effective against pressurized water entry during water washing of the vehicle. The present subject matter is directed to overcoming one or more problems as set forth in the background and thereby to obviate a lacunae in the prior art

[0007] One of the object of the present invention is to provide adequate sealing to the steering cage assembly against the ingress of undesirable foreign matter including pressurized water and dust. Another object of the present invention is to increase the durability of such steering cage assembly. A further object of the present invention is to provide a sealing assembly, for a steering cage assembly disposed at an endportion of the head tube, which is conveniently mounted without inteference or excess spacial requirements and is easily retrofittáble and serviceable. Various other features of the sealing assembly according to the present subject matter here will be discernible from the following further description thereof, set out hereunder.

[0008] The present invention thereofore discloses a steering system having a sealing assembly comprising an upper protective subassembly and a lower protective subassembly. The upper protective subassembly (170) comprises of a cylindrical cover and a sealing ring. The steering system has a steering tube rotatably accomodated within the head tube while maintaining clearance with the head tube. At least one steering cage assembly is rotatably connected to one endportion of the headtube so as to allow the steering tube rotate within the head tube with minimal effort. The cylindrical cover covers a portion of the steering tube protruding above the steering cage assembly. The sealing ring is co-axial with the cylindrical cover and áccomodated within the cylindrical cover so that the cylindrical cover is minimally supported on the sealing ring. The cylindrical cover comprises of a plurality of spaced drain holes on a radially outer surface positioned above the groove cutout of the steering tube. The pressurized water entering from the üpper portion of the steering tube is drained out through the drain holes.

[0009] The lower protective subassembly includes a double lip cover mounted lower to the cylindrical cover and a circular insert. The double lip cover is supported on an inner race member of the steering cage assembly whereas the circular insert is supported on and radially covers the outer race member of the steering cage assembly. Together the double lip cover and the circular insert form a sealed compartment around the steering cage assembly to completely seal the steering cage assembly. Thus, the cylindrical cover and the sealing ring jointly drain pressurized water before reaching the steering cage assembly whereas the sealed compartment prevenís pressurized water entry within the steering cage assembly. The cylindrical cover, sealing ring and sealed compartment also prevent entry of dust within the clearance between the steering tube and head tube. The cylindrical cover further prevenís the entry of water to the steering cage assembly through the groove cutout.

[00010] The foregoing objectives and summary is provided to introduce a selection of concepts in a simplified form, and is not limiting. To fully appreciate these and other objects of the present subject matter as well as the subject matter itself, all of which will become apparent to those skilled in the art, the ensuing detailed description of the subject matter and the claims should be read in corijunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[00011] The above and other features, aspects and advantages of the subject matter will be better understood with regard to the following description, appended claims and accompanying drawings where:

[00012] FIG. 1 shows a side view of a three wheeled automotive vehicle according to the present subject matter.

[00013] FIG. 2 shows a sectional view of a steering system according to the prior art.

[00014] FIG. 3 is an exploded view to show a sealing assembly operatively engaged with the steering system.
[00015] FIG. 4(a) - 4(f) show various components of the sealing assembly according to an embodiment of the present invention.

[00016] FIG. 5 is a cross sectional view to show the sealing assembly engaged with a steering cage assembly at an upper end of the head tube.

[00017] FIG. 6 shows a exploded sectional view of the sealing assembly covering the steering cage assembly engaged with the upper portion of the steering system.

DETAILED DESCRIPTION OF THE INVENTION

[00018] The subject matter disclosed herein relates to a sealing assembly which protects the steering cage assembly of a steering system from a failure caused due to accumulation of undesirable impurities like water and dust and its subsequent disfunctioning. In an embodiment, the sealing assembly is mounted on a vehicle' frame in a three wheeled automotive vehicle. The three wheeled automotive vehicle is mainly, but not solely, used as a pássenger carrier. It is to be noted that "front" and "rear", and "left" and "right" wherever referred to in the ensuing description, refer to front and rear, and left and right directions as seen in a state of being seated on a seat of the vehicle and looking forward. Furthermore, a longitudinal axis unless specified otherwise refers to a front to rear axis relative to the vehicle, while a lateral axis unless specified otherwise refers generally to a side to side, or left to right axis relative to the vehicle. Various other features of the sealing assembly according to the present subject matter here will be disceraible from the following further description thereof, set out hereunder.

[00019] FIG. 1 illustrates a side view of a concerned three wheeled pássenger carrier vehicle, referenced by the numeral 100, driven by an internal combustión engine. The vehicle can be used as a pássenger carrier vehicle or a load carrier vehicle. It has a front cowl 201 supporting a windscreen 202. The lower portion of the front cowl 201 is connected to a front wheel 204 with a wheel cover 203 disposed in between. A handle bar assembly 209 is present behind the front cowl 201 which is used to opérate the said three wheeled vehicle 100.. In this view, a steering system is not visible to an onlooker of the vehicle. The vehicle is longitudinally divided into two halves along the line X-Y; an anterior portion A having a driver's seat 207 while a posterior portion P having a long passenger seat 208 with a seating capacity of. mínimum three passengers. A rear panel (also known as rear compartrñent or rear cabin) 206 along with the posterior portion P of the vehicle containing the passenger seat 208 is supported on a pair of rear wheels 205 located on either side of the longitudinal axis of the vehicle 100.
[00020] FIG. 3 is an exploded view of the front portion of the vehicle. The vehicle comprises of a steering system 140 having a head tube 51, a steering tube 52 having a groove cutout 53 along the longitudinal axis of the steering tube and at least one steering cage assembly 62 disposed at an endportion of the head tube 51 and adjoining the steering tube 52. The steering tube 52 is rotatably engaged with the head tube 51 through the steering cage assembly 62 and maintains some clearance with the head tube 51 for trouble free rotational movement within the head tube. In an embodiment, the steering cage assembly is positioned at each endportion of the head tube as shown in FIG. 5. Thus, the steering system has an upper steering cage assembly referred by numberal 62 disposed at an upper endportion of the head tube and a lower steering cage assembly referred by numberal 61 disposed at a lower endportion of the head tube. However, for the purposes of brevity, only oné steering cage assembly referred by numeral 62 is explained. In an embodiment, the steering cage assembly 62 adjoins the steering tube 52, preferably the portion having the groove cutout 53.

[00021] As explicitly shown in FIG. 3 and FIG. 5, each steering cage assembly 62 comprises of an outer race member 125 having a first groove defined in an inner periphery of one end facing upwards thereof, an inner race member 119 having a second groove defined in a lower outer periphery thereof, and a plurality of beads 120 received in the first groove and positioned between the first groove and the second groove. A first lock nüt 110, a friction píate 111 and a second lock nut 112 along the longitudinal axis of the steering tube 52 facilitate operation of the steering. tube 52. They are disposed at a higher elevation than the steering cage assembly 62.

[00022] The steering system 140 further includes a sealing assembly provided to substantially cover the steering cage assembly 62 so that accumulation of undesirable foreign matter including water and dust in the steering cage assembly may be prevented. The components of the sealing assembly also partially cover the steering tube 52 and collectively prevent the movement of foreign matter like water and dust towards the steering cage assembly, leading to its better life and durability. The sealing assembly according to the present invention, as shown in FIG. 3, comprises of an upper protective subassembly 160 and a lower protective subassembly 170. The upper protective subassembly 160 includes a cylindrical cover 101 and a sealing ring 106. The lower protective subassembly 170 includes a double lip cover 113 and a circular insert 121. The upper protective subassembly 160 is disposed at a higher elevation than the lower protective subassembly 170.

[00023] FIG. 4(a) to 4(f) show various components of the sealing assembly according to an embodiment of the present invention. The cylindrical cover 101 has a stepped structure and is adapted to adjoin and veil a portion of the steering tube 52 protruding above the steering cage assembly 62. In an embodiment, the cylindrical cover 101 is substantially cylindrical and disposed above an upper endportion of the head tube 51. The cylindrical cover 101 has a plurality of spaced drain holes 104 on a radially outer surface 103.

[00024] As shown in FIG. 4(a) and 4(b), the cylindrical cover 101 has a stepped structure comprising an upper portion 141, a central portion 142 and a . lower portion 143 as shown in its cross-sectional view. The cross sectional área of the portions progressively increases downwardly with the upper portion 141 having the smallest área and the lower portion 143 having the largest área. Thus, the upper portion 141 is radially smaller than the central portion 142 and the central portion 142 is radially smaller than the lower portion 143. The lower portion 143 of the cylindrical cover 101 is supported on and covers the first lock nut 110 provided in the steering system.
[00025] Further, the upper portion 141 of cylindrical cover 101 has an upper ajar extremity 102a at its upper end and the lower portion 143 has a lower ajar extremity 102b at its lower end. The lower ajar extremity 102b is located opposite to the upper ajar extremity 102a. The cylindrical cover 101 also has a radially outer surface 103 joining the upper portion 141, the central portion 142 and the lower portion 143. All thé portions are formed integral and the cylindrical 'cover 101 is a single piece structure. The radially outer surface 103 has the upper ajar extremity 102a and the lower ajar extremity 102b respectively at opposite" ends. The two extremities have a circular structure though other similar structures are also possible. The upper ajar extremity 102a and the lower ajar extremity 102b together define a cylindrical through groove along the length of the cylindrical cover 101. Further, the diameter of the lower ajar extremity 102b of the cylindrical cover 101 is bigger than the upper ajar extremity 102a.
[00026] As shown in FIG. 5, the cylindrical cover 101 rests on the first lock
nut 110 which has a threaded inner periphery connected to the JocaJJy threaded radial outer surface of the steering tube 52. In a preferred embodiment, the lower portion 143 of the cylindrical cover 101 is supported on the first lock nut 110 such that the lower ajar extremity 102b rests on and covers the first lock nut 110. The width of the lower portion 143 is adjustable according to the width of the first lock nut 110.
[00027] The radially outer surface 103 of the cylindrical cover 101 has the
plurality of drain spaced holes 104 for draining the water received from the upper ajar extremity 102a of the cylindrical cover 101. According to an embodiment, the cylindrical cover 101 has at least three spaced drain holes 104a, 104b, 104c on the radially outer surface 103.
[00028] The sealing ring 106 has a circumferential flange 108 on its outer
periphery defining an upper groove 109a and a lower groove 109b, and a receiving groove 107 on its inner periphery to accommodate the steering tube 52. The sealing ring 106 is received from the lower ajar extremity 102b of the cylindrical cover 101. As shown in FIG. 4(c), the circumferential flange 108 extends radially outwardly from the sealing ring 106 and defines the upper groove 109a above the flange and the lower groove 109b below the flange 108. The central portion 142 of the cylindrical cover is supported on the upper groove 109a.

Thus, the sealing ring 106 is accommodated within the cylindrical cover 101 and is engulfed by the lower portion 143 of the cylindrical cover 101 so that it is not visible to an onlooker. The central portion 142 of the cylindrical cover is wider than the upper portion 141 to accommodate the sealing ring 106. The sealing ring 106 is co-axial to the cylindrical cover 101.
[00029] It is to be noted that the sealing ring is made of elastic material due
to which it is able to accommodate the variation in steering tube 52 and provide positive sealing always. It is press fitted to the steering tube 52.
[00030] In a preferred embodiment, the drain holes 104 are located at the
interface of the upper portion 141 and the central portion 142 of the cylindrical cover 101, although they may be disppsed at any place along the radially outer surface 103. Preferably, the drain holes 104 are positioned above the groove cutout 53 of the steering tube 52 and immediately above the upper groove 109a. Thus, the cylindrical cover 101 and sealing ring 106 jointly prevent the pressurized water from moving down towards the steering cage assembly 62 by way of drain holes 104 and by not allowing the pressurized water to go down beyond the sealing ring 106. The water entering the steering system through top portion of the steering tube accumulates at the upper groove 109a of the sealing ring 106 and is drained by adjoining drain holes 104 in the cylindrical cover 101. The cylindrical cover 101 laterally covers a portion of the groove cutout 53 and the drain holes do not allow the pressurized water to move down towards the groove cutout 53 and further down towards the lower steering cage assembly 61.

[00031] However, it is also possible that the pressurized water may enter
the steering cage assembly laterally. Therefore, the lower protective subassembly 170 is provided for further protection comprising a double lip cover 113 mounted lower to the cylindrical cover 101 and a circular insert 121. The double lip cover 113 is supported on the inner race member 119 of the steering cage assembly whereas the circular insert 121 is supported on and radially covers the outer race member 125 of the steering cage assembly.
[00032] The double lip cover 113 is provided above the steering cage
assembly 62 and mounted lower to the cylindrical cover 101. In an embodiment, the double lip cover 113 is positioned above and is supported on the inner race member 119 of the upper steering cage assembly 62. The structure of the double lip cover is now described as shown in FIG. 4(d) and 4(e). The double lip cover 113 comprises of a radially inwardly metal insert 114 contouring the steering tube 52 and protruding downwardly to form a lateral portion 116 connecting the metal insert 114 with at least two downwardly concentric elastic rings 117a, 117b. The metal insert 114 helps to withstand all the axial forces generated by the first lock nut 110 and second lock nut 112. The lateral portion 116 is cylindrical and defines an engaging groo ve 115 to receive the steering cage assembly 62 from the bottom. It branches out into the at least two downwardly concentric elastic rings 117a, 117b. In an embodiment, the metal insert 114, the lateral portion 116 and the elastic rings 117a, 117b are formed integrally.
[00033] The circular insert 121, as shown in FIG. 4(f), is disposed below
and ensures the centrality of double lip cover 113. It is supported on and radially

covers the outer race rhember 125 of the steering cage assembly 62 and has a radially inwardly flange 122 to rest the downwardly concentric elastic rings 117a, 117b of the double lip cover 113. When mounted, the so constructed double lip cover 113 and the circular insert 121 form a sealed compartment around the steering cage assembly 62, and protect the greased beads 120 from the lateral ingress of foreign matter like pressurized water as well as dust. The concentric elastic rings 117a, 117b further seal the steering cage assembly. The circular insert 121 provides a wear resist positive sealing of the outer race member 125 of the steering cage assembly 62 from foreign matter like dust and water. This also helps in frictionless rotationál movement of the steering tube 52 and reduced steering effort. In an embodiment, the diameter of the circular insert 121 is more than the double lip cover 113.
[00034] According to an aspect, the cylindrical cover 101 is made of a
group consisting of plástic, metal and alloy; the sealing ring 106 is made of an elastic material; and the circular insert 121 is made of a plástic material.
[00035] The present subject matter and its equivalent thereof offer many
advantages, including those which have been described henceforth. During the servicing or water wash of the vehicle, a portion of pressurized water is thrown laterally on the steering tube 52 and a pprtion is thrown from the top. The upper protective subassembly 160 prevenís the laterally thrown water from moving toward the radial outer surface of the steering tube 52. However, some of the pressurized water may percolate from the upper ajar extremity 102a of the cylindrical cover 101 toward the groove cutout 53 as shown in FIG. 6. Such flow

is stopped by the sealing ring 106 through its circumferential flange 108. The water is drained out through thé drain holes 104 located just above the sealing ring 106 and it does not stagnate. In this way, a major portion of the water used does not reach the steering cage assembly 62.
[00036] Similarly, the sealed compartment formed by the double lip cover
113 and the circular insert 121 prevenís the lateral ingress of pressurized water into the steering cage assembly 62. Thus, as shown in FIG. 6, due to the presence of upper protective subassembly 160 (cyíindrical cover lOTand sealing ring 106) which stop the downwards ingress, and the lower protective subassembly 170 (double lip cover 113 with the circular insert 121) which prevent lateral ingress, the steering cage assembly 62 is substantially sealed by the sealing assembly components. With this sealing assembly, the life of beads 120 in the steering cage assembly 62 is significantly improved and the steering cage assembly becomes more durable.
[00037] Further, because the water flowing from the top portion of the
steering tube is drained by drain holes 104 and sealed compartment does not allow any entry of water to steering cage assembly 62, no water is received in the groove cutout 53 unlike the prior art. Henee the lower steering cage assembly 61 is also sealed as no water or dust can flow through the groove cutout 53 towards the lower steering cage assembly 61 by using the clearance between the steering tube 52 and the head tube 51. Thus, the stagnation of water at the lower steering cage assembly 61 is prevented. Effectively, sealing the upper steering cage assembly 62 also seáis the lower steering cage assembly 61. The double lip cover

113 and the circular insert 121 can also be used in an in verted fashion to seal the lower steering cage assembly 61 from the water and dust. In this case, the circular insert 121 would be placed abo ve the double lip cover 113.
[00038] The components of the sealing assembly including the cylindrical
cover 101, sealing ring 106, double lip cover 113 and the circular inserí 121 can be conveniently mounted in the steering system without inteference or excess spacial requirements. They are also easily retrofittable in the existing vehicles . Further, the components of the sealing assembly are easily serviceable.
[00039] The present subject matter is thus described. The description is not
intended to be exhaustive ñor is it intended to limit the invention. to the precise form disclosed. It will be apparent to those skilled in the art that the disclosed embodiments may be modified in light of the above description. The embodiments described are chosen to provide an illustration of principies of the invention and its practical application to enable thereby one of ordináry skill in the- art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contémplated. Therefore the forgoing description is to be considered exemplary, rather than limiting, and the true scope of the invention is that described in the appended claims.

We claim:

1. A steering system (140) having a head tube (51), a steering tube (52)having a groove cutout (53) along the longitudinal axis of the steering tube, and at least one steering cage assembly (62) disposed at an endportion of the head tube (51) and adjoining the steering tube (52), said steering cage assembly comprising an outer race member (125), an inner race member (119), a plurality of beads (120) disposed between the outer race member (125) and the inner race member (119), characterised in that,
the steering system (140) includes a sealing assembly comprising an upper protective subassembly (160) and a lower protective subassembly (170) wherein the sealing assembly prevenís any undesirable impurities including pressurized water from moving towards the at least one steering cage assembly of the steering tube.

2. The steering system as claimed in claim 1, wherein the upper protective subassembly (160) includes: a sealing ring (106) having a circumferential flange (108) on its outer periphery defining an upper groove (109a) and a lower groove (109b), and a receiving groove (107) to accommodate the steering tube (52); a cylindrical cover (101) adapted to adjoin and veil a portion of the steering tube (52) protruding above the steering cage assembly (62) and having a plurality of spaced drain holes (104) on a radially outer surface (103), the drain holes (104) positioned abo ve the groove cutout (53) of the steering tube immediately above the upper groove (109a); and wherein the lower protective subassembly (170) includes: a double lip cover (113) supported on the inner race member (119) of the steering cage assembly (62) and mounted lower to the cylindrical cover (101) and having at least two downwardly concentric elastic rings (117a, 117b); and, a circular insert (121) supported on and radially covering the outer race member (125) of the steering cage assembly (62) and having a radially inwardly flange (122) to rest the downwardly concentric elastic rings (117a, 117b) of the double lip cover (113); and wherein further the cylindrical cover (101) and the sealing ring (106) are co-axial and the sealing ring (106) is accommodated within the cylindrical cover (101).

The steering system as claimed in claim 2, wherein the double lip cover (113) and the circular insert (121) form a sealed compartment around the steering cage assembly (62).

The steering system as claimed in claim 2, wherein the cylindrical cover (101) has a stepped structure comprising an upper portion (141) with an upper ajar extremity (102a), a central portion (142) and a lower portion (143) with a lower ajar extremity (102b) opposite to the upper ajar extremity (102a) and receiving the sealing ring (106), all portions formed integral and joined by the radially outer surface (103), and wherein further the upper portion (141) is radially smaller than the central portion (142) and the central portion (142) is radially smaller than the lower portion (143).

5. The steering system as claimed in claim 4, wherein the lower portion (143) of the cylindrical cover (101) is supported on and covers a first lock nut (110) provided in the steering system.

6. The steering system as claimed in claim 2 or claim 4, wherein the drain holes (104) are located at the interface of the upper portion (141) and the central portion (142).

7. The steering system as claimed in claim 2, wherein the double lip cover (113) comprises of a radially inwardly metal insert (114) contouring the steering tube (52) and protruding downwardly to form a lateral portion (116) formed integral with the downwardly concentric elastic rings (117a, 117b).

8. The steering system as claimed in any of the preceding claims, wherein the cylindrical cover (101) is made of a group consisting of plástic, metal and alloy; the sealing ring (106) is made of an elastic material; and the circular insert (121) is made of a plástic material.

9. A sealing assembly for a steering system (140) comprising an upper protective subassembly (160) and a lower protective subassembly (170), the upper protective subassembly (160) further comprising:
a sealing rin (106) having a circumferential flange (108) on its outer periphery defining an upper groove (109a) and a lower groove (109b), and a receiving groove (107) to accommodate the steering tube (52); and, a cylindrical- cover (101) adapted to adjoin and veil a portion of a steering tube (52) protruding above a steering cage assembly (62) and having a plurality of spaced drain holes (104) on a radially outer surface (103), the drain holes (104) positioned above a groove cutout (53) of the steering tube immediately above the upper groove (109a);'the sealing ring (106) accommodated within the cylindrical cover (101); and, the lower protective subassembly (170) further comprising: a double lip cover (113) supported on the inner race member (119) of the steering cage assembly (62) and mounted lower to the cylindrical cover (101) and having at least two downwardly concentric elastic rings (117a, 117b); and, a circular insert (121) supported on and radially covering the outer race member (125) of the steering cage assembly (62) and having a radially inwardly flange (122) to rest the downwardly concentric elastic rings (117a, 117b) of the double lip cover (113); wherein the sealing assembly prevenís any undesirable impurities including pressurized water from moving towafds the steering cage assembly of the steering tube.

10. A vehicle comprising a steering system including a sealing assembly.as claimed in any of the preceding claims.