The present application is a continuation in part of my co-pending application Serial No. 288,281 entitled Adjustable Shock Absorbing Handlebar Structure filed in the United States Patent Office on July 6, 1981 and that will issue as Patent No. 4420989 on December 20, 1983. Field of the Invention

The present invention relates to a handlebar assembly particularly suitable for use on motorcycles used off the road for racing over rough terrain.

In the past it has been common practice to have the forked forward structure of a motorcycle or motorcycle like vehicle that rotatably supports the front wheel of the vehicle to be guided by a pair of handlebars ^" of rigid-structure that terminate.on the ends ^" thereof in grips that are engaged by the rider. As a motorcycle of this structure travels over rough

and uneven terrain such as is encountered in racing, the shock of the forward wheel of the vehicle as it moves upwardly and downwardly in traversing the uneven terrain is transmitted through the handlebar of the motorcycle -to the arms- of the rider, with this shock being so severe that at times in racing the rider must give up as his arms are no longer able to withstand the constant strain imposed thereon by vibrations and shocks imparted to them through the handlebar structure.

A major object of the present invention is to provide a shock absorbing handlebar structure that may be removably secured to an existing motorcycle or embodied as an integral part of a new vehicle, with the handlebar structure of the present invention minimizing the shock transmitted from the front wheel of the vehicle to the hands of the rider as the vehicle transverses uneven terrain such as is encountered in racing. - _

Another object of the invention is to supply a shock absorbing assembly that may be manually

adjusted to a desired preloading, and that will lessen the. shock .' transmitted to the steering mechanism only when the force of the shock exceeds a predetermined magnitude.

A still further object of the invention is to furnish a shock absorbing assembly ^' that may be manually adjusted for the particular off road terrain over which the vehicle will travel.

These and other objects and advantages of the invention will become apparent from the following description of a number of forms thereof. Summary of the Invention

The handlebar assembly of the present invention is adapted either for incorporation in the structure of a new motorcycle or motorcycle-like vehicle, or as a retro-fit on an existing motorcycle.

The assembly is adapted for mounting on the steering structure of a power operated vehicle, the steering structure including a wheel supporting structure pivotally mounted at the front end of- the vehicle. The handlebar assembly includes a

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handlebar structure for gripping at opposite ends by the driver and an assembly for connecting the handlebar structure to the wheel supporting structure such that the wheel can be turned by turning the handlebars. The connecting assembly includes a shock absorbing assembly for lessening shocks above a predetermined magnitude from being transmitted to the handlebar structure.

The shock absorbing assembly may be mounted between the handlebar and wheel supporting structure, or it may be mounted independently so as to oppose or damp upward or downward vertical motion of the handlebar structure. It preferably includes means for exerting an upward force of a predetermined magnitude on the handlebar structure so as to maintain it normally in a predetermined orientation. A manual adjusting device may be provided for varying the upward force.

The shock absorbing assembly preferably, comprises at least one hydraulic piston and cylinder assembly including piston and cylinder members

slidable relative to one another, one of the members being secured to the handlebar structure and the other of the members being arranged to be secured to part of- the_vehicle steering structure, such as the wheel supporting structure or the pivotal support for that structure. The pressure of a fluid, such as air, in one end of the cyclinder is preferably, arranged to be manually adjustable.

When the shock absorbing assembly is incorporated into the structure of a new motorcycle or motorcycle like vehicle, it is preferable to use the tube at the forward portion of the frame on which the pair of triple clamps are pivotally supported to establish a pressurized air chamber and hydraulic chamber within the interior thereof. An elongate member that supports the handlebar structure is longitudinally movable within the tube and in an opening in the uppermost one of the triple clamps in axial alignment with the interior of the tube. The elongate member cannot rotate relative to the pair of triple clamps.

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First and second pistons are situated within the tube and so operatively associated with ^' the elongate member that the pressurized air at all times exerts a predetermined upward force on the handlebar. When the motorcycle is subjected to a shock force of greater intensity than ^' the predetermined magnitude hydraulic fluid is forced through at least one transverse opening in the second piston and in so doing lessening the degree of shock transmitted to the handlebar.

When the shock absorbing assembly is used as a retro fit on an existing motorcycle the handlebar is supported by a pair of laterally spaced, downwardly extending members that are slidable in tube like cylinders that preferably depend from the uppermost one of the triple clamps. Pairs of first and second pistons are operatively associated with the pair of elongate members and tubes. The first pair of pistons are by air or resilient means urged upwardly to preload the handlebar with an upward force of a desired magnitude. The pair of second pistons each

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have at least one transverse passage therein through which hydraulic fluid is forced when the intensity of the shock to which the motorcycle is subjected is greater than the predetermined upward force. The forced flow of hydraulic fluid through the passages lessens the magnitude of the shock transmitted to the handlebar of the motorcycle.. . Brief Description of the Drawings

Figure 1 is a perspective front view of a first embodiment of a handlebar assembly according to the invention;

Figure 2 is a side elevational view of the central part of the assembly shown in Figure 1;

Figure 3 is a top plan view showing the shock absorbing unit of the assembly of Figures 1 and 2;

Figure 4 is a vertical cross-sectional view taken on the line 4-4 of Figure 2;

Figure 5 is a cross-sectional view of a center portion o the assembly taken on the line 5-5 of Figure 2; ^" _■- ^' .- -

Figure 6 is a longitudinal cross-sectional view

of the center portion of the invention taken on the line 6-6 of Figure 2?

Figure 7 is a fragmentary cross-sectional view of an end portion of the invention illustrating one of the grips, and taken on the line 7-7 of Figure 1;

Figure 8 is a perspective view of another embodiment of the handlebar shock absorbing assembly;

Figure 9 is a vertical cross-sectional view of the shock absorbing handlebar assembly shown in Figure 8 and taken on the line 9-9 thereof;

Figure 10 is a combined front elevational and longitudinal cross-sectional view of the assembly shown in Figure 9 and taken on the line 10-10 thereof;

Figure 11 is a combined front elevational and longitudinal cross-sectional view . of another embodiment of the shock absorbing handlebar assembly;- - "

Figure 12 is -a side elevational view of a further embodiment of the invention;

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Figure 13 is a side elevational view of another embodiment of the invention;

Figure 14 is a longitudinal cross-sectional view, of the assembly shown in Figure 13 taken on the line 14-14.of Figure 13;

Figure 15 is a side elevational view showing a further modification of the invention;

Figure 16 is a transverse cross-sectional view taken on the line 16-16 of Figure 15;

Figure 17 is a top plan view of a further embodiment of the invention; and

Figure 18 is a side elevational view of the assembly of Figure 17. Description of the Preferred. Embodiment

Figures 1 to 7 show a first embodiment of the handlebar assembly A of the present invention. The assembly A is secured to a conventional steering assembly of a motorcycle. A forward tube C is supported by the frame of the motorcycle ^" and acts as a -pivotal, mounting for a wheel support assembly. The support assembly comprises upper and lower

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plates D of generally triangular shape to which a- pair of laterally spaced wheel support forks E are secured. The pair of plates D are referred to commonly in the- motorcycle trade as triple clamps. The support forks E rotatably support the forward wheel of the motorcycle (not shown).

The handlebar assembly includes a handlebar structure 10 and a connecting assembly 11 for operatively connecting the handlebar structure to the steering assembly.

The connecting assembly 11 includes a pair of spaced clamps F projecting upwardly from the upper plate D and a rigid frame G supported from the clamps having laterally spaced first and second end pieces 12 an 14.

The first end piece 12 pivotally supports first upper and lower cross members 16 and 18 of the handlebar structure that are pivotally and adjustably connected on_their outer ends by a. first generally vertical support 20 that has a first grip 22 projecting, outwardly therefrom.

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Second upper and lower cross members 24 and 26 of the handlebar structure are pivotally connected to the second end piece 14, with the outer ends of the- second pair of cross members pivotally and adjustably connected to a second vertical support 28 that has a second grip 30 projecting outwardly therefrom.

The connecting assembly further includes a shock absorber J mounted between the end pieces 12 and 14.

A first link assembly H is connected to the first upper cross member 16 and by a first stud bolt 32 is pivotally connected to an internally threaded ring 34 as shown in Figure 3 that engages external threads 36 on the shock absorber J. A second link assembly K extends between the second lower crossd member- 26 and a second bolt 40 that projects outwardly from ring 34.

In detail it will be.seen in Figures 2 and 5 that- each of the clamps ^" F includes a rigid lower block 42 that has a transverse semi-circular groove

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44 extending there-across, and an upper block 46 that has a transverse semi-circular groove therein. A pair of screws 50 extend downwardly through bores 52 formed in upper block 46 as shown in Figure 5 to threadedly engage tapped recesses 52a ^' formed in the lower block ^~ 42.

The end pieces 12 and 14 of frame G as shown in Figure 3 are formed from rigid channels that have adjacent disposed vertical webs 12a and 14a. A first pair of flanges 12b extend from the edges of first web 12a as may be seen in Figures 2 and 3. upper and lower pairs of flanges 14b and 14c extend from second web 14a.

Webs 12a and 14a have a lower rigid tube 54 secured thereto as shown in Figure 2 that forms a part of frame G and is removably gripped by the pair of clamps F when the screws 50 are tightened. Frame G is completed by an upper heavy tube 56 that extends between first and second-fianges- 12a and 14a as shown in-Figures 1 and 2.

The upper and lower second cross members 24 and

26 as may best be seen in Figures 2, 3 and 4 have their inner ends rigidly secured to upper and lower transverse tubular members 24a and 26a that are rotatably supported on transverse bolts 58 and 60 that extend between the upper and lower pairs of flanges 14b and 14c. Likewise the upper and lower first cross members 16 and 18 have their inner ends rigidly secured to transverse tubular members 16a and 18a that are pivotally supported on bolts 62 and 64 that extend between the pair of flanges 12b.

The first link assembly H includes a first rigid member 66 that depends from tubular member 16a and is rigidly secured thereto. The lower end portion of member 66 as viewed in Figure 3 is. pivotally connected by a screw and nut assembly 68 to a first end portion of an elongate rigid first link 70, that has a second end portion in which a transverse bore 70a is formed that pivotally engages first bolt 32. First bolt 32 has threads thereon that are engaged by a nut 72 to maintain first link ^{^} 70 in engagement with first bolt 32.

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The second link assembly K as best seen in Figures 2 and 3 is similar in structure to the first link assembly H. The second link assembly K as seen as seen in Figure 4. includes a second rigid member 74 that is welded or otherwise rigidly secured to tubular member 26a and on its upper end portion as viewed in Figure 2 is by a screw and nut assembly 76 pivotally connected to a first end portion of a rigid second link 78, which second link includes a second end portion in which a transverse bore 78a is formed that pivotally engages the second bolt 40. Bolt 40 has threads thereon that are engaged by a nut 80 to removably maintain second link 78 in pivotal engagement with the second bolt 40.

Shock aborber J as may be best seen in Figure 6 includes a cylindrical shell 82 that has internal threads 82a defined on a first end portion thereof that engage external threads formed on a first end piece 84. First- end piece 84 has -a; centered transverse bore 84a therein from which a groove 84b

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extends outwardly. Groove 84b supports a resilient sealing ring 84c.

Second internal threads 82b are formed on a second end portion of shell 82. A second end piece 86 is provided as shown in Figure 6 that has external threads thereon that engage second threads 82b. Second end piece 86 has a centered transverse bore 86a extending outwardly therefrom in which a second sealing ring 86c is disposed.

First and . second axially aligned transverse bores 88 and 90 are formed in the first and second vertical webs 12a and 14a as may be seen in Figure 6. An elongate piston rod 92 is provided that has a bore 94 extending longitudinally therethrough, with the piston rod having first and second external end portions on which first and second threads 92a and 92b are defined thereon. The bore 94 has first and second end portions in which first and second internal threads 94a_ and 94b are defined as shown in Figure 6.

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A piston 96 extends outwardly from piston rod 92 and is disposed within shell 82 as shown in Figure 6. Piston 96 has a circumferential groove 96a in the outer peripheral portion thereof in which a resilient sealing ring 96b is disposed that slidably and sealingly engages the interior surface 98 of cylindrical shell 82. Piston 96 has first and second side surfaces 96c and 96d.

A number of circumferentially spaced, transverse, apertures 100 extend through piston 96. A ring shaped valve plate 102 is mounted on piston rod 92 to the left of piston 96 as viewed in Figure 6 and is urged into sealing contact with second piston side surface 96b by a circular resilient ring 104 of arcuate transverse cross section. Resilient ring 104 has the inner periphery thereof in abutting contact with a snap ring 106 that engages a groove 108 in the piston rod 92. The ^" piston 96 subdivides the interior of shell 82 into first and second compartments 110 and 112- of variable volume in which

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a hydraulic liquid L is contained. Valve plate 102 prevents the flow of hydraulic liquid L from second compartment 112 to first compartment 110.

A first ring shaped resilient ^" pad 114 ^" is mounted on piston rod 92 between first end piece 84 and first web 12a. A first nut 116 engages threads 92a. A pair of second nuts 118 engage the second threads 92b on opposite sides of the second web 14a as shown in Figure 6. A second ring shaped resilient pad 120 is mounted on the piston rod 92 between first and second ring shaped pressure plates 122 and 124. Second pressure plate 124 abuts against second end piece 86. A third nut 126 engages threads 92b and bears against first pressure plate 122.

The first and second vertical supports 20 and 28 have the upper and lower portions thereof adjustably engaged by identical clamp assemblies L, one of which is shown in- detail in Figure 7. ^" Each clamp assembly L includes a slightly resilient body 150 that has a vertical bore 152 therein that

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communicates with a transverse slot 154 defined between first and second outwardly extending legs 156 and 158. Bore 152 snuggly engages an end portion of one of the- supports 20 or 28. Legs 156 and —15-8 have transversely aligned bores 156a and 158a therein through which a screw 160 extends that is engaged by a nut 162.

Each body 150 has a pair of legs 164 extending therefrom at approximately 90 degrees from the legs 156 and 158. The pair of legs 164 have aligned transverse bores 166 therein through which a bolt 168 extends. The bolt 168 also extends through a transverse sleeve 170 found in the outer end portions of one of the cross members 16, 18, 24 and 26.

By loosening the nuts 162 the first and second supports 20 and 28 can be pivoted to dispose the grips 22 and 30 at desired angles relative to the first and second .pair of cross bars 16, 18, - 24 and 26 for a particular rider. A- second position for the grip 22 is shown in phantom line in Figure 7 and

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identified by the numeral 22*.

The first compartment 110 is in communication with a first port 180 on the right hand side of piston 96 a\s_yiewed in Figure 6, with the first port also in communication withjoore 94 that communicates with a second port 182 in the piston rod to the left of the piston as shown in Figure 6. Port 182 is in communication with second compartment 112.

The left hand end of bore 94 as viewed in Figure 6 has threads 94b formed therein that are removably engaged by an externally threaded plug 190. The first threads 94a are engaged by a threaded end portion 192 of a rod 194 that has a first end 196. End portion 192 has an outer face 198 in which a non-circular cavity 200 is defined to permit rotation of the rod 194 by a hand tool (not shown). Rod 194 is disposed in bore 94. Rod 194 has a circumferential groove 202 therein in which a resilient sealing ring 204 is disposed that, sealingly engages the interior of bore 94. An internally threaded locking ring 206 engages threads

36 as shown in Figure 6 and serves to hold ring 34 at a desired longitudinally adjusted position on hydraulic cylinder shell 82.

The use and operation of the invention A is as follows. By rotating the rod 194, the rod may be moved longitudinally to partially reduce ^" the effective cross section of the first port 180 to reduce the rate of flow of hydraulic liquid L between the first compartment 110 and second compartment 112. Likewise by rotating the nut 126 in an appropriate direction, the first pressure plate 122 as viewed in Figure 6 is moved to the right to increase compression on second resilient pad 120 and through hydraulic cylinder J to secon compression pad 114 to increase the compression on the latter.

When the ring 34 is moved longitudinally relative- o the shell 82 the first and second.link assemblies H- and K are concurrently pivoted to pivot the first upper and lower cross bars 16 and 18 and second upper and lower cross bars 24 and 26 upwardly

and downwardly to a desired angle relative to the upper plate 10. As such pivotal movement takes place the first and second grip supports 20 and 28 move upwardly and downwardly in a vertical direction due to the clamp assemblies L affixed thereto being pivotally connected to the outer end portions of the first upper and lower cross bars 16 and 18 and second upper and lower cross bars 24 and 26. The first and second grips 22 and 30 as previously described are pivotally adjustable to desired angles relative to the first and second sets of upper and lower cross bars 16, 18, 24 and 26.

When the forward wheel of the motorcycle on which the handlebar assembly A is mounted encounters a rough portion of terrain that causes the first upper and lower cross bars 16 and 18 and second upper and lower cross bars 24 and 26 to pivot downwardly and inwardly towards one another the first link assembly H tends to jρush the hydraulic shell 82 to the left relative to the piston 96 and the second link assembly tends to pull the shell in

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the same direction, with the shock being transferred to the second resilient pad 120 to compress the same. Concurrently, hydraulic liquid flows from the first compartment 110 -to the second compartment 112 through ports 180, bore 94 and port 182, at a rate predetermined by the pre-selected position of the rod 194. Hydraulic liquid L in first compartment 110 is subjected to sufficient pressure to flow through apertures 100 by unseating sealing ring 102. Hydraulic liquid L has now entered second compartment 112 that has expanded in volume and in so doing has absorbed a part of the shock.

After the shock is over, the second resilient pad 120 tends to expand to the right, in so doing contracting the size of second compartment 112, due to the shell 82 moving to the right relative to piston 96. The spring loaded valve plate 102 will not allow flow of hydraulic fluid through apertures 100 into first compartment 110. A portion of the shock as second resilient pad- tends to expand longitudinally and pivot first upper and lower cross

bars 16 and 18 and second upper and lower cross bars upwardly relative to plate 10 is absorbed by hydraulic liquid flowing through port 182, bore 94 and restricted port 180 into first compartment 110 that is increasing in volume. As second resilient pad 120 expands to the right, shell 82 moves to the right, and a portion of the shock is absorbed by first resilient pad 114.

By adjusting the position of the rod 194 and the compression on the pads 114 and 120, the shock absorbing assembly can be adjusted to a desired preloading so that the shock transmitted to the handlebars is lessened only in response to force of a predetermined magnitude. Thus adjustments can be made according to the roughness of the terrain over which the motorcycle is to be driven.

A second embodiment of the handlebar assembly is shown in Figures 8 to 10. In Figure 9, upper and lower motorcycle frame members 210 and 212 support a forwardly tilted tube 214 that serves as a pivotal mounting for upper and lower plates 216 and 218 of

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generally triangular shape. The pair of plates 216 and 218, referred to commonly in the motorcycle trade as triple clamps, have a pair of laterally spaced wheel supports forks 220 secured thereto.

The handlebar assembly includes a handlebar 228 and a connecting assembly 215 for operatively connecting the handlebar to the motorcycle steering assembly.

The upper plate 216 has an upwardly tilted forward portion 216a in which a pair of laterally spaced tapped openings 222 are defined. The tapped openings 222 are engaged by externally threaded bushings 224 that have internally threaded first tubes 226 forming part of the connecting assembly secured thereto and extending downwardly therefrom.

The connecting assembly further includes a pair of clamps 230 removably gripping the center portion 228a of the handlebar 228. The clamps are secured to the upper ends of a pail: of second tubes 232 that extend downwardly through bushings 224 into the first tubes 226 to terminate in a pair of first

pistons 234.

The lower ends of the first tubes 226 are closed by a pair of plugs 236 that extend upwardly through openings 238 in a cross piece 240. Each of the plugs 236 has a ^" rod 242 that extends upwardly therefrom through a bore 244 in a first piston 234 and supports a second piston 246 on the upper end thereof. The plugs 236 are provided with O-rings 248 that seal with cross piece 240. Each first piston 234 is provided with O-rings 250 and 252 that seal with rod 242 and the interior surface of one of the first tubes 226. Each second piston 246 has an O-ring 254 on the exterior surface thereof that seals with the interior surface of one of the second tubes 232.

Each of the clamps 230 is illustrated as including a rod 256 that extends downwardly in one of the second tubes 232 and slidably supports a third piston 258 that is at all times biased downwardly by a helical spring 26Q-.... Third piston 258 includes an O-ring 262 on the exterior surface

thereof that slidably seals with the interior surface of one of the second tubes 232. Each first piston 234 and third piston 258 cooperate with the second tube in which they are disposed to define a confined space 264 that is filled__w_ith hydraulic fluid H. Each second piston 246 has a number of transverse passages 266 therein.

Each rod 242 has a pair of resilient bumpers 268 that serve to limit the upward and downward movement of the first piston 234 relative to the second piston 246 and first plug 236.

The cross piece 240 intermediate the pair of first plugs 236 has an opening 270 therein that is engaged by a second plug 272 from which a pressurized air reservoir 274 extends upwardly. A valve stem 276 is mounted on the upper end of reservoir 274.

Air pressure is discharged through valve stem

.276 into -reservoir 274 until a desired pressure is

_reached_. Each, of the first plugs 236, first piston

234, and portion of one of the first tubes 226

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cooperate to define a confined space 278 of variable volume that by passages 280 in the f irst plug 236 , cross piece 240 , and second plug 272 i s in communication with the interior of air reservoir 274.

Air under pressure from reservoir 274 at all times exerts a force of predetermined magnitude on the pa i r of f ir st pi stons 234 to maintain the handlebar 228 in the upward position shown in Figure 10. Upon the assembly being subjected to a shock of an intensity gr eater than said pr edetermined magni tude each second tube 232 tends to move downwardly relative to one of the second pistons and is restrained from sharp movement by hydraulic fluid being required to flow thr ough passages 266 and the third piston 258 moving longitudinally on a rod 256 to compress one of the spr ings 260 , all of which results in the degree of shock transmitted from the pair, of- forks' 220 to the handlebar 228 being substantially lessened. ^• - ^' -

A further embodiment of a handlebar shock

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absorbing assembly is shown in Figure 11. " The assembly may be used on a motorcycle (not shown) having a front end structure of the type illustrated in Figure 8 that includes an upper plate 316. In Figur e 11 it w ill be seen that the connecting assembly includes a pair of laterally spaced clamps 330 supporting handlebar 328, that are secured to the upper ends of a pair of tubes 332 that extend downwardly through a pair of bushings 324 secured to the upper plate 316. The lower ends of the pair of first tubes 332 are engaged by a pair of plugs 336 that extend upwardly through aligned openings in a cross piece 340. A pair of tubular rigid guides 350 extend downwardly from plate 316 and slidably engage the pair of first tubes 332.

A third plug 352 that is externally threaded extends upwardly through a centered opening in cross piece 340 and engages the lower internally threaded end of an upwardly extending cylindrical shell 354. The upper end of shell 354 is closed by an end piece 356. A transverse partition 358 sub-divides the

interior of shell 354 into a pressurized air chamber 360 and a hydraulic fluid chamber 362. A rod 364 is secured to plate 316 as shown in Figure 11 and extends downwardly through openings in end piece 35.6 and partitiro-n 358. _, The lower end of rod 364 supports a first piston 366. The rod 364 supports a second piston 368 for longitudinal ^" movement within the hydraulic fluid chamber 362. Second piston 368 has a number of transverse passages 370 therein as shown in Figure 11. First and second pistons 366 and 368 have O-rings 366a and 368a on the exterior thereof that slidably seal with the interior surface of shell 354. Partition 358 supports an O-ring 358a in slidable sealing engagement with rod 364. A valve 372 permits pressurized air to be discharged into chamber 360 through a passage 374 in plug 352. The shell 354 and the components therein comprise a shock absorbing unit.

In operation, the pressurized air in chamber. 360 will at all times exert ari upward force on first piston 366 and maintain it in abutting contact with

partition 358 , and the handlebaar 328 at a maximum height above plate 316.

When the plate 316 is subj ected to a sharp upwardly directed shock it tends to move upwardly abr uptly relative to the f i rst tubes 332 and transmit the shock to the handlebar. However , the shock absorbing unit substantially lessens the intensity of the shock transmitted to the handlebar 328. As such movement takes place the first piston 366 moves downwardly relative to shell 354 to further compress the air in chamber 360, and remove a portion of the shock. The second piston 368 tends to move downwardly relative to shell 354 with hydraulic fluid H being forced upwardly through passages 370 to cushion the magnitude of the shock transmitted to the handlebar 328.

After the shock is over, the compressed air in chamber 360 tends to . move the shell 354 downwardly relative ^' to first piston 366 and dispose partition 358 in abutting contact with the first piston. Abrupt movement in this direction is prevented by

the hydraulic fluid H above second piston 368 being forced to flow downwardly through passages 370 to a position therebelow.

In Figure 12 another -embodiment of the handlebar shock absorbing- assembly is shown that is similar to the embodiment shown in Figure 11. Elements common to both embodiments are identified by the letters and numerals previously used but with primes added thereto. In Figure 12 the guides 350* extend to cross piece 340' and are secured thereto as is the shell 354. The rod 364' is pivotally connected to a bracket 400 that moves with the first tubes 332'. The embodiment of Figure 12 operates in the same manner as the embodiment of Figure 11. In Figure 11 the shell 354 moves relative to rod 364 while in Figure 12 the rod 364' moves relative to the shell.

Two further embodiments of the invention are shown in Figures 13 and 14, and Figures 15 and 16, respectively. In both embodiments the tube 214' of the motorcycle frame is employed as a part of the

handlebar shock absorbing assembly. Elements common to previously described embodiments are identified by the numerals previously used but with primes added thereto.

In Figures 15 and 16, ^" handlebar 2.28 ¹ is secured by a clamp 230' to the upper end of a tube 500 that has longitudinal splines 500a that engage non- rotatably in a splined opening (not shown) in upper plate 216' and then extends downwardly into tube 214' to terminate in a first piston 502. First piston 502 supports an O-ring 502a in a slidable sealing engagement with the interior surface of tube 214'.

Tube 214' has a lower end closure 504 from which a rod 506 extends upwardly through an opening 508 in first piston 502 to terminate in a second piston 510 that has transverse passages 510a therein. The interior of tube 500 and first piston 502 cooperate to define a chamber 512 that is filled with hydraulic fluid H. First piston 502, .lower end closure 504, and tube 214' cooperate to define a

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σhamber 514. Pressurized air is discharged into chamber 514 through a valve 516. First piston 502 has an O-ring 518 mounted thereon that slidably and sealingiy engages rod 506.

Pressurized air in chamber 514 exerts .an upward force on first piston 502 to maintain handlebar 228' in maximum upward position shown in Figure 15. Only a portion of the shock to which plates 216' and 218' are subjected is transmitted to handlebar 228* due to movement of tube 500 relative to second piston 510 which forces hydraulic fluid through passages 510a. Resilient bumpers 520 and 522 are mounted on rod 506 to limit longitudinal movement of first piston 502 in tube 214'. Tube 214' and the components therein comprise the shock absorbing unit.

In Figures 13 and 14, the pair of forks 220' are tubes having closed lower ends (not shown) and on the upper ends threadedly engage a pair of bushings 530 that are mounted on the upper plate 216'. Forks 220' extend through openings in plate

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218' and are secured to the latter. A pair of tubular members 532 are slidably mounted in the upper portions of tubes 530 , one of which tubular members is shown in Figure 7. Each tubular member 532 has a circular stop 534 on the lower end thereof that may contact one of the bushings 530.

The upper ends of tubular members 532 support clamps 536 in which handlebar 228' is mounted. Each tube 220 ' has a compressed helical spr ing 538 therein that bears against one of the clamps 536 to maintain handlebar 228' at maximum elevation above upper plate 216'. A substantially horizontal rigid connector 540 extends from the tube 500' to the pair of clamps 536. The shock absorbing unit C ¹ is the same as that shown in Figure 15 with the springs 538 to minimize the shock transmitted to the handlebar 228* when the vehicle on which they are mounted traverse rough terrain.

The structure and operation of the invention has been described previously in detaii and need, not- be repeated.

Figures 17 and 18 show a further embodiment of the handlebar assembly which is, as in the previous embodiments , secured to a motorcycle steer ing assembly comprising pivotally supported triple clamps to- hich the front wheel support forks (not shown) are secured.

In Figures 17 and 18 only the upper plate 216 of the triple clamps is visible. The handlebar 228 is operatively connected to the upper plate 216 via a connecting assembly comprising a pivotal linkage and a shock absorber C . The plate 216 has an upstanding bracket member 600 secured at its front end. Pivotally mounted between opposed end plates 602 of the bracket member 600 is a rod 604 which extends into shock abso rbing uni t C. Shock absorbing unit C the same as unit C shown in Figure 15. Thus rod 604 terminates in a piston (not shown) which slides in the tube 214 ' or cylinder of the shock absorbing unit.. As -in the embodiment of F igur e ' 15 , a valve (not shown ) i s pr ovi ded to- control the air pressure in a chamber between the

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piston and the opposite end of the cylinder.

At the rear end of the plate 216 an upstanding bracket 606 having opposed end plates 608 is secured. A pair of lower link members 610 are each pivotally connnected at one end to a respective one of the end plates 608. A pair of upper link members 612 each having a longer leg 614 and a shorter leg 616 are each secured at end 620 of their shorter legs 616 to a transverse member 622 (see Figure 17) which is connected to the tube or cylinder 214' of the shock absorbing unit. Member 622 may be formed integrally with the cylinder or welded to it. The corner .point 623 of each link member 612 is pivoted to the adjacent end plate 608.

The ends of the upper and lower link members 610, 612 remote from the bracket 606 are pivotally secured to respective ones of a pair of flanges 624. Each flange 624 depends downwardly from a respective one of a pair of clamps 626 -in which the handlebar 228 is gripped, as best shown in Figure 17.

Thus the pressure of the air in the cylinder 214' will maintain the handlebar 228 in a normally elevated position due to the cylinder arid transverse member 622 acting on the pivotal link member 612 so that the flange 624 is held at the inclination shown in Figure 18.

When the motorcycle wheel passes over - uneven ground, shock transmitted to the handlebar 228 is damped by the hydraulic shock absorbing unit C . An upwardly directed shock would tend to move the front end of plate 216 upwardly, thus moving the piston inside shock absorbing unit C inwardly. Howeever, movement of the piston is damped by the compressed air at one end of the cylinder and

_ _^ hydraulic fluid in inner chambers at the other end, as in the previous embodiments shown in Figures 8 to 16. Thus the magnitude of the shock transmitted to the handlebar via link members 612 is cushioned.

Thus all the embodiments described above show a handlebar assembly ^" which incorporates a shock - absorbing assembly for minimizing or reducing shocks

transmitted from the wheel to the hands of a rider. The shock absorbing assemblies can be manually adj usted to a desired preloading, to allow for the roughness of the terrain over which the vehicle is to travel. ^~

While the invention has been particularly shown and described with reference to the preferred embodiment, it will be understood that modifications can be made to the disclosed embodiments without departing from the scope of the invention, which is defined in the appended claims.

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