*

BACKGROUND OF INVENTION ø. This invention relates to the point of articulation for a shaft within a bore. More specifically this invention relates to devices forming the point of articulation between a tow vehicle a a trailer. Prior art articulation points used pins within a shaf and/or bushings to support pivotal or rotational movement. These wore out quickly and allowed undesirable movement between the tow vehicle and trailer, resulting in excessive vibration, expensive repairs and unwanted down time. This invention uses bearings at all points of movement. Bearings provide long service life and freedom from unwanted movement or vibration resulting from clearance spaces between pins and bushings. The invention also eliminates the tedious trial and error process for positioning sa bearings and setting bearing preload. The problem of setting bearing preload is solved by the use of a locking means and beari spacer with accompanying parts.

In the prior art, a tow vehicle and trailer such as a Jeffre Ramcar, had a rotationally moveable pivot bracket, assembly which was mounted to the tow vehicle through a pivot bracket assembly bore. Rotational movement was made possible by a barrel turning steel bushings. Rotational movement allows the tow vehicle and trailer to roll relative to each other about their axis of travel (the x axis) . The pivot bracket assembly also has a tongue assembly which allows the tow vehicle and trailer to pivot relati to each other about a vertical axis.

The "rotational" bushings in the pivot bracket assembly had very large diameter with respect to their length and were positioned close together. Because the bushings were close together, a small amount of diametrical clearance allowed a ' relatively large amount of angular movement. Any angular movemen is unwanted because the tow vehicle and trailer are designed to b

rigid with respect to each other in the x-y plane. (Defined as t x axis being horizontal and along the direction of the tow vehicl and trailer and the y axis vertical.) Thus, even a brand new Jeffrey Ramcar allowed undesired angular movement. Necessary clearance space for rotational movement between the bushing and t barrel surface inside the bushings also allowed for undesired angular movement. Even small amounts of angular movement caused vibration of the tow vehicle and driver as the tow vehicle and trailer flexed in the x-y plane at the point of articulation.

Both the bushings and the barrel of the rotationally moveabl pivot bracket assembly were steel. The steel-on-steel movement caused both parts to wear out quickly. Typically, the bushings h to be replaced after only four to six months of service use. Angular movement between the bushing and the barrel increased wit wear, soon causing extreme vibration and jarring of the driver. The jarring and vibration caused driver fatigue and could in some cases cause driver injury. The angular movement also tended to wear the pivot bracket assembly bore out of round, permanently damaging the bore. Thus, new bushings needed to be installed at least two to three times per year to prevent damage to the bore. This maintenance procedure was time consuming and costly.

Once the bore was worn out of round by the undesired angular movement, installation of new bushings would not reduce the angul movement or reduce the vibration on the driver because the out-of round bore would continue to allow excessive angular movement. Hence, the bore was unrepairable. In extreme cases this would result in the tow vehicle and trailer separating at the pivot bracket assembly, causing the tractor to plunge forward into the ground endangering both the equipment and the driver. The same problems were found in the tongue assembly which allowed the undesired movement between a steel pin positioned in a steel tong assembly. OBJECTS OF THE INVENTION

One object of this invention is to eliminate undesired angul movement of a pivot bracket assembly of a tow vehicle and trailer

Another object of this invention is to lengthen the service

life of a pivot bracket assembly.

Another object of this invention is to eliminate damage to a pivot bracket assembly.

Another object of this invention is to set and maintain bearing preload between a shaft and a bore.

Another object of the invention is to eliminate the tedious shim selecting process used in setting proper bearing preload.

Another object of this invention is to provide a method for retro-fitting existing tow vehicle and trailer articulation point to provide for the advantages of the invention. SUMMARY OF INVENTION

The invention improves the articulation point between a shaf and a bore. In the one embodiment, the invention is described fo use on tow vehicles and trailers. In the embodiment described in this specification, the invention is applied to a Jeffrey Ramcar (Model No. 4114) used in the mining industry and manufactured by Dresser Industries. The invention replaces bushings in the pivot bracket assembly with bearings and bearing cups. The use of bearings in the bore (rather than a bushing requiring some minimu clearance space to allow movement) prohibits angular movement. When properly preloaded, a bearing and bearing cup assembly has n clearance space and allows movement only about its rotational axi Therefore, no angular movement is possible. Further, the inventi eliminates undesired angular movement that resulted' fjrom wear of the bushings caused by the steel on steel friction. The bore will no longer wear out of round and service life will be extended.

In the preferred embodiment, this invention includes an apparatus for setting and maintaining bearing preload between a shaft and a bore by the use of an endplate, a housing, a flanged pin, an optional pin cone spacer and a locking means. This invention also includes an application of the apparatus in a devi for connecting a tow vehicle and a trailer which allows movement between the tow vehicle and trailer in the x-z and y-z planes, while maintaining rigidity in the x-y plane. The invention furth encompasses a method for fitting or retro-fitting a tow vehicle a trailer articulation point with the inventive device. The

invention can also be used whenever rotation of a shaft within a bore is desired.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a tow vehicle and trailer combination, including reference axes.

FIG. 1A depicts an exploded view of a pivot bracket assembly.

FIG. 2A depicts a cross sectional view of the pivot bracket assembly with the invention installed in the tongue assembly.

FIG 2B depicts a cross sectional view of the pivot bracket assembly with the invention installed in the rotational bore assembly.

FIG. 3 depicts a flanged pin and pin cone spacer assembly use in the invention.

FIG. 4 depicts a locking means housing used in the invention.

FIG. 5 depicts a Ringfeder locking means.

FIG. 6 depicts a cross section of a Ringfeder locking means.

FIG. 7 depicts an endplate used in the invention.

FIG. 8 depicts measurement of bearing cone clearance for the selection of a cone spacer.

FIG. 9 depicts use of an assembly tool to ensure proper bearing seating on the pin flange. DETAILED DESCRIPTION OF THE BEST MODE OF THE INVENTION

Referring to Fig. 1, prior to installation of the invention, Jeffrey Ramcar tractor (tow vehicle) 101 and a trailejr 102 exhibit unwanted angular movement in the x-y plane. Said tow vehicle and said trailer are connected at a point of articulation shown generally at 103. Rotational movement in the y-z plane is shown generally as 202. Pivotal movement in the x-y plane about a vertical axis y is shown generally as 201. Both Figures 1A and 2A depict part of said pivot bracket assembly 103. Shown in Figure 2 is a tongue assembly 300 which allows pivotal movement about a vertical y axis. Shown in Figure 2B is a rotational bore assembly 301.

Referring now to Fig 1A, said pivot bracket assembly 103 is comprised of a tongue assembly 300. Said tongue assembly 300 is comprised of at least one "double" vehicle tongue 314 [an upper

vehicle tongue 314(a) and lower vehicle tongue 314(b)] and one "single" trailer tongue. Said pivot assembly may have one or mor such tongue assemblies. In the Jeffrey Ramcar, there are two tongue assemblies and the invention can be applied to both. For the purpose of this description, only one tongue assembly will be described. Said vehicle tongues 314(a) and 314(b) have circular bores through said tongues 315(a) and 315(b) respectively. Said trailer tongue 330 has a circular trailer tongue bore 331 through said trailer tongue. Said trailer tongue bore and said vehicle tongue bores are sized and configured to fit a pin positioned in said bores.

Said vehicle tongues 314(a) and 314(b) are attached to said tow vehicle 101 at said rotational bore assembly 301. In the pri art, said trailer 102 is allowed to pivot up or down from said to vehicle 101 due to required clearance space for movement between the prior art pin and tow vehicle tongue bores 315 (a) and 315 (b) and trailer tongue bore 331. This clearance space was required t allow pivotal movement, shown as 201. Said trailer 102 is also allowed to pivot up or down due to the positioning of a bushing (not shown) located within said rotational bore assembly 301 and inside a rotational assembly bore 302, shown in Fig. 2B. Movemen in the x-y plane caused undesired vibration and jarring of the to vehicle 101.

Referring now to FIG 2A, the invention provides an improved pivot assembly between vehicle tongues 314(a) and 314(b) and trailer tongue 330. Bearings cones 321(a) and 32Kb) (hereinafte "bearings") and corresponding bearing cups 322(a) and 322(b) are used to allow pivotal movement about a novel, flanged pin 324. I the preferred embodiment, said bearings are tapered roller bearin which are used in pairs. Movement in the x-y plane caused by clearance of the prior art pin is eliminated. Said bearings 321( and 32Kb) and corresponding bearing cups 322(a) and 322(b) allow no clearance for movement in the x-y plane. Only desired rotational movement 202 about a vertical bearing axis is permitte by the invention. The use of tapered roller bearings and bearing cups is well known to those skilled in the art.

T HEET

It is necessary for bearings to have bearing preload when the are placed. Bearings subjected to an excessive preload will develop heat during use, wear quickly, and suffer a reduced servic life. A bearing assembled with inadequate preload will allow movement within a bearing cup when subjected to forces. Such movement of a bearing in a bearing cup can cause damage to both th bearing and bearing cup, thus drastically reducing service life. The invention eliminates these problems by ensuring that proper bearing preload is set and maintained through the use of a novel, flanged pin 324. Said flanged pin 324 positions a flange 401 between said bearings to provide proper spacing between tapered roller bearings. Said bearings are brought into contact with said flange and cannot be forced further into said bearing cups causing excessive bearing preload.

In the preferred embodiment, said flange is combined with a pin cone spacer 325. Said pin cone spacer is used to add thicknes to said flange 401. This provides the user with a better fit and easier use since said flanged pin can be manufactured to a standar size. Use of an optional pin cone spacer 325 is made when additional space is required between bearings 32.1(a) and 32Kb) to achieve proper bearing preload.

In the prior art, preload of tapered roller bearings was set by trial and error. Bearings were placed and fixed into position then turned to determine if a proper amount of torque, (usually suggested by the manufacturer) was required to turn them. If bearing preload was not in the desired range, the apparatus was disassembled, a shim was selected by an educated guess to achieve preload in the proper range, and the apparatus was reassembled. This procedure was repeated if necessary. Improper bearing preloa would result in accelerated wear to said bearing and said bearing cup, a reduced service life and inferior reliability.

The invention eliminates the use of shims by pre-measuring th distance between bearings when seated properly and using a flange 401 and in some cases an optional pin cone spacer 325.

The problem of setting bearing preload in the prior art was made more difficult when two bearings were used on the same shaft

with separate fastening means. In the prior art, as one bearing was tightened down, it affected the preload of the other bearing the same shaft. Thus, it was difficult to accurately set bearing preload for two bearings on the same shaft.

This invention replaces the prior art pivot assembly (simply steel pin within vehicle tongue bores 315 (a) and 315 (b) and trail tongue bore 331) with a novel pin retention assembly 104. Articulation is achieved by the use of two mutually dependent bearings 321(a) and 321(b) and corresponding bearing cups 322 (a) and 322(b). Said pin retention assembly 104, comprises a flanged pin 324, a pin cone spacer 325, bearings 321(a) and 32Kb), beari cups 322(a) and 322(b), locking means housings 317(a) and 317(b), locking means 320(a) and 320(b), endplates 319(a) and 319(b), a plurality of endplate/pin bolts 326 and a plurality of endplate bolts 308.

Referring to FIG. 3, a flanged pin 324 and pin cone spacer 32 are shown. In one embodiment said pin 324 is machined from 4140 steel. Other materials are also suitable for fabrication of said pin 324. In this example, said pin 324 is 5 3/8" in total height with its widest diameter being near the pin midpoint at a pin flange 401 which is 4 7/16" in diameter and 0.250" in thickness. As stated above, said flange is used to space said bearings. Therefore, different thicknesses of said flange can be machined f different uses.

In the preferred embodiment, said pin 324 is stepped to allo use of standard available bearings and bearing cups as well as standard available locking means. Depending on the bearings and locking means used, it may be unnecessary for said pin to be stepped. In the preferred embodiment, said pin 324 has an upper first step 402 of diameter of 4.001" and length of 1 1/2". Said pin has a lower first step 403 of diameter 4.001" and length 1 3/8". Said upper first step 402 and lower first step are sized t fit inside said bearing 321(a) and 32Kb). Therefore, other dimensions of said steps are possible for use with different bearings. Said pin can be beveled at its edges to provide for easier installation.

Said pin has an upper second step 406 of diameter 3.750" and length 1 1/16". Said pin has a lower second step 408 of diameter 3.750 and length 1 1/16". Said upper second step and lower second step are sized to fit inside said locking means 320(a) and 320(b) .

Said pin 324 also comprises a pin center hole 410 in the preferred embodiment for use in greasing said pin retention assembly 104. Said pin center hole 410 has a 5/16" diameter and extends longitudinally through the center of said pin 3.24. At bot ends of said pin, said pin center hole 410 has a counterbore hole 411. Said counter-bore hole 411 is 7/8" diameter by 1/8" deep. Said counter-bore holes can be fitted with grease fittings to allo grease to be inserted into said pin. The use of grease fittings i well known to those skilled in the art.

Said pin also comprises one or more endplate/pin holes 414. In the preferred embodiment, three endplate/pin holes are drilled longitudinally through said pin 324 spaced at 120° on a 2 1/4" bol circle diameter. Said endplate/pin holes have a diameter of 9/16". A plurality of endplate holes 414 are provided to allow bolts to extend through said endplates 319 (a) and (b) through said pin 324 to hold the entire pin retention assembly together.

In the preferred embodiment, said pin has one or more grease holes 416 drilled radially through said pin flange 401 perpendicular to said pin center hole 410. Said grease hole is drilled through said pin flange 401 to said pin center hole 410. Said grease hole is approximately 1/8" to 3/16" in diameter. When said pin retention assembly 104 is installed, said bearings 321(a) and 32Kb) may be greased by pumping grease into pin center hole 410. One end of said pin center hole is closed so that grease wil be forced into said pin center hole 410 and through said pin greas hole 416 to said bearings 321(a) and 321(b) .

Said pin cone spacer 325 is fabricated from mild steel in the preferred embodiment. Other materials are also suitable for fabrication of said pin cone spacer 325. The outside diameter of said pin cone spacer 325 should be approximately 4 1/2" and sized to fit on said pin flange 401. The inside diameter of said pin cone spacer should be approximately 4.002" and sized to fit over

said upper first step of said pin. The thickness of said pin con spacer 325 should be approximately 0.200". Thickness of said pin cone spacer will vary for different applications.

Said bearings 321(a) and 32Kb) can be purchased ready to install. In the preferred embodiment, said bearings are tapered roller bearings. With slight modifications, other bearings such spherical bearings can be used. This example uses Timken bearing (Timken cone # 52400) . For other applications, different sizes o bearings can be used.

Corresponding bearing cups 322 (a) and 322(b) are used with said bearings. In this example, Timken Cup # 52637-B are used. Said bearing cups are inserted into said trailer tongue bore 331. Said bearing cups have a flanged area at the base of each cup whi is used to hold said bearing cup on said trailer tongue. The use of bearings and bearing cups are well known to those skilled in t art.

Referring now to FIG. 4 a locking means housing 317 is shown Said locking means housing 317 may be made from A-35 steel. Othe materials are also be suitable for fabrication of locking means housings. Two locking means housings 317(a) and 317(b) are used the preferred embodiments. In other embodiments, it is possible that said tongue bores 315 (a) and 315 (b) can be the locking means housing. It is necessary for said pin to be locked to said trail tongue. A separate locking means housing is used in _^ the preferre embodiment to alter the dimensions of said tow vehicle tongue bor to a smaller bore opening for use with the flanged pin. ^* In some cases, said locking means housing may be a bore in a machine memb itself. Due to the desired use of available bearings and ring bindings, it is desirable to alter the size of said tow vehicle tongue bores by use of separate locking means housing. For the purposes of this specification, said locking means housing will mean any bore capable of being locked to said pin by said locking means whether said housing be a separate piece or not.

In the preferred embodiment, however, said locking means housing has circular shape and is sized and configured to fit sai tow vehicle tongue bores 315(a) and 315(b) . In this example, sai

locking means housing has a 8 3/4" outer diameter and is 1 5/16" thick. The dimensions and examples are given for only one of said locking means housings. The other locking means housing has identical dimensions.

The interior portion of said circular locking means housing 317 is bored out to form a locking means housing bore 601 with an inside diameter of approximately 5.310". Said housing bore 601 is sized to fit over said endplate 319 and around a locking means 320

Said locking means housing has a housing step 605 which is used to rest said locking means housing 317 on said tow vehicle tongue 314 and extend into said tow vehicle tongue bore 315. Said housing step 605 has an outer diameter of approximately 6.125" and a depth of 3/4".

Said locking means housing is attached to said tow vehicle tongue by means of a plurality of housing bolts 318 and corresponding mounting holes 606. In the preferred embodiment, said mounting holes 606 have a diameter 11/16" and are placed on a 7 1/2" bolt circle diameter. In the preferred embodiment, six mounting holes 606 are evenly spaced and used with corresponding housing bolts 318 to fix said locking means housing 317 to said to vehicle tongue 314. Corresponding tapped 5/8" holes are drilled i said tow vehicle tongues for accepting said housing bolts 318. Lock washers may be used in connection with said housing bolts for a more secure fit.

In one embodiment, two housing removal holes 608 can be drilled 180° apart on a 7 1/2" bolt circle diameter on said lockin means housing 317. Said housing removal holes 608 can be drilled and tapped to a 1/2" diameter for use with a puller during disassembly.

Locking means 320(a) and 320(b) are used to lock said bearing in place and to secure said pin rigidly to said tow vehicle tongue bores 315(a) and 315(b). In the preferred embodiment, said locki means is a ring binding. A ring binding is a binding which fits around said pin 324 and inside said locking means housing 317(a) and 317(b) respectively. Said ring binding is adapted to lock sa

pin to said housing. In the preferred embodiment, said locking means is a Ringfeder binding. Referring to Fig. 5, a Ringfeder locking means 320 is shown. In this example said locking means i a Ringfeder binding #RFN 7012 - IN with an inside diameter of 3-3/4 The use of Ringfeder bindings is known to those skilled in the ar The use of a Ringfeder binding or similar locking means 320 is an improvement over the prior art. Referring to Fig. 6, a cross- section of a Ringfeder binding is shown. A Ringfeder binding comprises a wedge shaped rear thrust ring 904 and a wedge shaped front thrust ring 905. Said thrust rings contact an inner surfac 902 and an outer surface 903 which also have wedge shaped cross sections. A plurality of endplate bolts 308 connect said front a rear thrust rings. As endplate bolts 308 are tightened, said thrust rings 904 and 905 are brought closer together and the wedg shapes enabled said front and rear thrust rings to push outward o said inner surface 902 and outer surface 903. It is this outward movement which provides a binding effect by forcing the inner surface 902 against said pin 324 and said outer surface 903 again said locking means housing 317 which is positioned in said tow vehicle bores 315(a) and 315(b) as shown in Fig. 2A.

The strong gripping force of said Ringfeder binding effectively locks said bearing in place in its preloaded position Said bearing is locked in place against said pin flange or pin co spacer. Said bearing cannot move out of said bearing cup due to the placement of said locking means 320 on the outside of said bearing. The strong gripping force of said locking means prevent slippage and is capable of withstanding axial thrust forces.

Referring to FIG. 7 an endplate 319 is shown. Said endplate 319 may be machined from A-36 or 1045 steel. Other materials are also be suitable for fabrication of endplates. Said endplate has circular shape with diameter approximately 5.290 and a thickness 0.725". In the preferred embodiment, two endplates 319(a) and 319(b) are used. The dimensions and assembly examples are given for one endplate, but can be repeated for the other endplate. A groove 501 can be machined around the outside circumference of sa endplate for holding an 0 ring 323. In one embodiment, said grov

is 0.140" wide and has a diameter of 5.090". Said groove 501 is positioned near the middle of said endplate. An 0 ring is placed in said groove to keep out water, dust, etc.

Said endplate comprises a plurality of holes 505 which are drilled in position to align with holes in said locking means 320. In one embodiment said endplate holes have a diameter of 27/64". In order to coincide with the holes in a Ringfeder locking means, said endplate holes 505 are spaced at 20 degrees apart with a 4.527" bolt circle diameter concentric with the center of the said endplate 319. Said endplate holes 505 are configured to accept endplate bolts 308 which pass through said endplate into said locking means and connect said endplate to said locking means.

In one embodiment, one or more of said endplate holes can be drilled out to a diameter of 1/2" to assist in disassembly of said pin retention assembly. In addition, two removal holes 508 with a 3/8" diameter, spaced 180 degrees apart from each other on a 3 1/4" bolt circle diameter, can be drilled in said endplate. Said removal holes facilitate removal of said endplate 319 during disassembly. A puller can be used in connection with said removal holes 508 to aid in removing said endplate.

Said endplate 319 also comprises a means for securing said pi and said endplates together. In the preferred embodiment, said endplate also comprises a plurality of endplate/pin holes 509. In the preferred embodiment, said endplate has three endplate/pin holes 509 with 9/16" diameters on a 2 1/4" bolt circle diameter. Said endplate/pin holes 509 correspond to said pin/endplate holes 414 drilled in said pin 324. Endplate/pin bolts 326 extend throug said first endplate 319 (a) , said pin 324 and extend through a second endplate 319(b) and are secured with a nut and lock washer. These endplate/pin bolts hold the entire pin retention assembly together.

Said endplate can also include a puller hole 510 with a 1 1/8 diameter located in the center of said endplate 319. Said puller hole 510 is tapped for use with a puller when removal of said endplate 319 is desired during disassembly. Said puller hole 510 also allows access to said pin center hole 410 for greasing said

pin retention assembly 104.

The invention can be improved by replacing the prior art bushing and bore arrangement of said pivot bracket assembly. Referring to FIG. 2B, said rotational bore assembly 301 provides for rotational movement in the y-z plane. In some tow vehicle an trailer configurations (such as the Jeffrey Ramcar) said tow vehicle has a pivot bracket bore 302 in which one or more bushing (not shown) are situated for allowing said trailer to pivot with respect to said tow vehicle. A barrel 310 is inserted into said bore and rests on the bushings. This bushing/bore configuration subject to the same problems experienced in the prior art pin assembly arrangement. The steel-on-steel wear of the barrel on t bushing causes unwanted vibration and excessive wear. The clearance space necessary for the barrel and bushing adds to thes problems. For this reason, the bushing/bore arrangement can be replaced by use of bearings.

Said tow vehicle has a cylindrical pivot bracket bore 302 an a cylindrical pivot bracket barrel 310. Said pivot bracket assembly bore 302 and barrel 310 are aligned with said tow vehicl and trailer (along the x axis) . In the preferred embodiment, sai pivot bracket bore has an inside diameter of 16.42". Said barrel has an outside diameter of approximately 14.75" and is approximately 9.082" in length. Both ends of said pivot bracket assembly bore 302 are machined out to a depth of .86" _^ to allow placement of bearings 303 (a) and 303 (b) and corresponding bearing cups 304(a) and 304(b) at each end of said pivot bracket bore 302. The inside diameter of the machined out area in the ends of said pivot bracket assembly bore is approximately 16.999". In the preferred embodiment, said bearings are tapered roller bearings (Timken Cone #LL 264648). Bearing cups 304(a) and 304(b) are (Timken Cup # LL 264610). Said bearing cups 304(a) and 304(b) ar placed in said bore grooves. Said tapered bearings are placed in said bearing cups with the tapered faces toward each other. Said pivot bracket barrel 310 has a larger barrel lip 309 which is siz and configured to rest against the rear bearing 303 (a) positioned in said bearing cup 304(a) . In one embodiment, said barrel lip 3

has an outside diameter of approximately 19" .

Said pivot bracket barrel 310 is inserted into said pivot bracket bore 302 and turns on said bearings. In order to hold sai barrel in place, the forward (tow vehicle) end of said barrel 310 is threaded for approximately 2" to fit a large nut 307. Said nut has an outside diameter of 19" and is brought into contact with said bore. Said nut 307 has an inside diameter of 14-3/4" and is threaded to accept the threaded end of said barrel 310.. Said nut is approximately 2" deep. When said nut is placed on said barrel and tightened, said barrel lip 309 is brought into contact with th rear end of said pivot bracket bore 302. Said nut is secured in place relative to said barrel by the prior art means used on the Jeffrey Ramcar. Said nut could also be secured by use of set screw or other means without departing from the invention.

Proper bearing preload is achieved by use of a bore cone spacer 306. Said bore cone spacer is sized and situated to fit between said bearings inside said bore. In the preferred embodiment, said bore cone spacer has an outside diameter of 15- 7/16" and an inside diameter of 14-15/16". Said bore cone spacer is approximately 9" long. Said bearings are forced against each end of said bore cone spacer 306 by the force exerted when the nut 307 is tightened on said barrel and said barrel lip is brought int contact with said bore. Said bore cone spacer insures the proper bearing preload of said bearings 303(a) and 303(b) by. not allowing said bearings to be forced too hard into said bearing cups. When the proper bore cone spacer is used, bearing preload is maintained in a proper manner.

Seals 305(a) and 305(b) may be used at each end of said bore to keep out dirt, etc. In the preferred embodiment, said seals ar circular neoprene seals which approximate the size of the end of said pivot bracket assembly bore 302. Said seals have a 19" outer diameter and 16 3/8" inner diameter and are 1/4" thick. DESCRIPTION OF PREFERRED METHOD OF USE

The following specification describes the preferred method of installing the invention to form an improved point of articulation between a tow vehicle and trailer. The invention can be used on

vehicles originally configured to use a pivot bracket assembly. The use of the invention is described for vehicles which have pivotal movement about a vertical y axis and rotational movement about a horizontal x axis. The example given is for use on a Jeffrey Ramcar. The example sets forth the steps for retro¬ fitting an articulation point between a tow vehicle and a traile The invention could also be installed at the time of manufacture a variety of tow vehicle and trailer combinations or on other applications when movement is desired of a shaft within a bore. Many of the steps can be carried out in a different order and st achieve the desired result.

The dimensions of parts and machined surfaces used in this example are selected largely to allow for the use of readily available over-the-counter parts. The use of over-the-counter parts in this example necessitates that parts of the existing to vehicle and trailer be modified to fit the invention. It is als possible to manufacture the tow vehicle and trailer parts to fit standardized parts. Other dimensions or other equivalent parts be used without departing from the invention.

If necessary, said trailer tongue bore 331 is enlarged to accept said bearing cups 322(a) and 322(b). In one embodiment, said bearing cups are Timken Cup # 52637-B. Bearing cups 322(a) and 322(b) are placed in said trailer bore 331 such that the standard flange of said bearing cup 322(a) is firmly _^ seated agai the top of said trailer tongue 330 and the standard flange of sa bearing cup 322 (b) is firmly seated against the bottom of said trailer tongue. Next, said trailer tongue is positioned in betw said tow vehicle double tongue 314 so that said bore holes in sa tow vehicle tongues (315(a) and 315(b)) and said trailer tongue bore 331 are aligned. Next, said lower bearing 32Kb) is placed said pin 324 with its tapered face positioned to fit in said bearing cup 322 (b) . It may be necessary to heat said bearing fo it "to fit on said pin.

Next, an optional pin cone spacer 325 of predetermined thickness may be placed on top of said pin flange 401. Said pin cone spacer is selected by first measuring the distance between

said bearings seated in said bearing cups on the trailer tongue. The following procedure is used to determined the proper dimension of an optional pin cone spacer 325. FIG. 8 illustrates the use of a c-clamp 701 to seat tapered roller bearing cones 321(a) and 32Kb) (Timken Cone #52400) in corresponding bearing cups 322(a) and 322(b) . Once seated in place a dial caliper or other measuring device is used to measure the clearance between said bearing cones 321(a) and 32Kb). Said bearing cups 322(a) and 322(b) are installed in said trailer tongue bore 331. Said bearing cones 321(a) and 32Kb) are temporarily placed in said bearing cups and held firmly by c-clamp 701. The clearance between said bearing cones 321(a) and 32Kb) is measured. If the clearance space between said bearing cones is greater than the thickness of said flange 401, a pin cone spacer is selected to augment said flange and provide proper spacing between said bearings. This procedure may also be used to measure bearing clearance for bore cone spacer assembly in the horizontal axis pivot bearing assembly bore.

Said pin 324 is positioned in said tow vehicle tongue bores 315(a) and 315(b) and trailer tongue bore 331. Said upper bearing 321(a) is positioned in corresponding bearing cup 322(a) and placed on said pin 324. Next, said locking means housings 317(a) and 317(b) are placed on said tow vehicle tongues. In the preferred embodiment, said housings 317(a) and 317(b) are attached to said tow vehicle tongues 314(a) and 314(b) by means of housing bolts 318 which fit in mounting holes 606 as described above. Lockwashers can also be used with said housing bolts 318 for added security. Said housing bolts 318 should be tightened to 175 - 200 ft. lbs. of torque.

FIG. 9 illustrates the use of assembly tools 801 to ensure proper seating of said bearings. Said bearing cups 322 (a) and 322(b) are installed in said trailer tongue bore 331. Bearing cone 321(b) is placed over the bottom end of said pin 324 and moved firmly against said pin flange 401. It may be necessary to heat said bearing cone 32Kb) to fit over said pin.

Next, an optional pin cone spacer 325 is selected with a thickness such that the total thickness of said pin cone spacer 325

and pin flange 401 equals said clearance 702 between said bearing cones 321(a) and 32Kb). A tolerance of plus 0.001" or minus 0.003" for the spacing between said bearings is suggested for bes results. Said pin cone spacer 325 is placed in position on said pin. Said pin 324 is placed into said trailer tongue bore 331 through the bottom so that said bearing cone 32Kb) is properly seated in said bearing cup 322 (b) .

The next step is to slide the top bearing cone 321(a) over t top of the pin 324 and rest against said pin cone spacer 325 located on the top side of said pin flange 401.

Next, an assembly tool 801 is placed at the top and bottom o said pin 324, as shown in FIG. 9. Said assembly tool 801 consist of a piece of pipe 802 with a tool endplate 803 having a pluralit of tool holes 804 tapped in said endplate 803 to 5/8" diameter on 2 1/4" bolt circle diameter. The height of said pipe 802 should at least 1" with an inside diameter in the 3 13/16" to 4 1/8" ran and an outside diameter no greater than 5.300". A piece of threaded rod 805 is inserted into each of said tool holes 804 in said tool endplate 803 and brought into contact with said pin. Tool nuts 806 are turned onto said rod 805. Said tool nuts 806 a tightened against said endplates 803 on each assembly tool 801 until said bearing cones 321(a) and 32Kb) are firmly seated against said pin flange 401 and pin cone spacer 325. Once this i accomplished, the assembly tools 801 may be removed- and the bearings are seated.

Said locking means is a means capable of binding said pin 32 to said locking means housing 317. Said locking means 320(a) and 320(b) bind said pin 324 to said locking means housing, which is turn bolted to said tow vehicle tongues 314.

Said locking means 320(a) and 320(b) and endplates 319(a) an 319(b) should be assembled with endplate bolts 308. Said endplat bolts 308 should be left two or three turns loose when first used to attach said endplate to said locking means. One or more endplate holes can be drilled out to a diameter of 1/2" to assist in disassembly. These disassembly holes 507 can be aligned with tapped notes on said locking means. The bolts which go into said

disassembly holes 507 should be used with lockwashers.

The invention uses a plurality of endplate bolts 308. Said endplate bolts 308 are pushed through said endplate holes 505 and inserted into the corresponding aligned bolt holes in said locking means 320(a) and 320(b). Said endplates and locking means are placed on each end of said pin. Endplate/pin bolts 326 are inserted and tightened in place through the entire pin retention assembly 104 to apply an equal amount of force to each bearing 321(a) and 32Kb). Endplate/pin bolts 326 are fitted with nuts and lockwashers and tightened in stages until 150 ft. lbs. of torque is obtained. Bearing preload between the two bearings 321(a) and 32Kb) is set and equalized by use of said pin flange 401.and an optional pin cone spacer 325.

Said endplate bolts 308 are then tightened. Said locking means and endplate bolts 308 should be tightened in two or three stages until a torque of 50 ft. lbs. is reached. For best results, said endplate bolts 308 should be tightened in some alternating sequence rather than tightening them in order around said endplate. When said endplate bolts 308 are tightened, said locking means 320 is forced in place against said pin and said locking means housing as described above. Said rear thrust ring 904 in said locking means 320 (a) is abutted against said upper bearing 321(a). Said rear thrust ring 904 and said front thrust ring 903 are brought toward each other when said endplate bolts 308 are tightened. Tightening said bolts 308 acts to clamp said locking means in place and set proper bearing preload by use of said pin flange 401 and an optional pin cone spacer 325. Said pin flange 401 and pin cone spacer 325 maintain a minimu distance between said bearing cones 321(a) and 32Kb). Tightening said locking means 320(a) and 320(b) into place does not effect bearing preload; it simply holds all components firmly in place so that proper bearing preload is constantly maintained. Excessive torque applied to said endplate bolts 308 during assembly will not cause excessive bearing preload due to the presence of said, pin flange 401 and said pin cone spacer 325 which keep said bearings 321(a) and 32Kb) at a minimum distance from each other.

An 0 ring 327 can be installed around the flanges of said bearing cups 322(a) and 322(b) to act as a grease seal. An 0 rin 323 can be installed around said endplates 319(a) and 319(b) to seal out dust, water, etc. In this embodiment said 0 ring has a 1/8" cross-section and is 5 5/16" in diameter.

The use of the invention can be improved by retro-fitting or building a pivot bracket assembly with a new or modified horizont rotational bore assembly. Referring to FIG. 2B said tow vehicle 101 includes a rotationally moveable pivot bracket assembly 301. Said rotationally moveable pivot bracket assembly 301 is mounted said tow vehicle 101 through a pivot bracket assembly bore 302. Said pivot bracket assembly bore 302 is hollow to allow electrica and hydraulic cables and a driveline to connect said tow vehicle 101 and said trailer 102. The following paragraphs explain necessary steps for improving said rotational bore assembly.

Bore grooves 308(a) and 308(b) are machined in opposite ends of said pivot bracket assembly bore 302. Said bore grooves are sized to accommodate bearing cups 304(a) and 304(b) at each end o said pivot bracket assembly bore 302. Said bore grooves are 0.86 in length in the preferred embodiment and machined to a depth tha yields an inside bore groove diameter of approximately 16.999". The distance between said grooves 308 should be approximately 9.030".

The remainder of the interior of said pivot bracket assembly bore 302 is machined to an inside diameter of 15 1/2". A rotationally moveable pivot bracket barrel 310 is machined to an outside diameter of approximately 14.750". The rear (trailer) en of said barrel has a barrel lip 309 which is sized to fit against said pivot bracket assembly bore 302. The front (tow vehicle) en of said barrel should be threaded for approximately 2" to fit a nut 307.

Said nut 307 is drilled and tapped to fit the threaded end o said barrel. Said nut has an inner diameter of approximately 14.75". The outer diameter of said nut is sized so that it fits against the front bearing 303(b) which is seated in said bearing cup 304(b). Said bearing cup is in turn seated in a groove in sa

pivot bracket assembly bore. Thus said barrel is secured in place by attaching said nut. In the preferred embodiment, said nut has an outer diameter of 19" and is 2" deep. Said nut may be secured in place relative to said barrel by using the same technique as in the prior art. The nut may also be secured in place by use of set screws or other means.

A bore cone spacer 306 should be fabricated from mild steel o other suitable material with an overall length of 9.082.". The outside diameter of said bore cone spacer should be 15 7/16" and a inside diameter of 14 15/16". Said bore cone spacer 306 is sized to fit around said barrel 310 and within said pivot bracket assembly bore 302. The bore cone spacer is long enough to fit between said bearings 303(a) and 303(b) . Preload of said two tapered roller bearings 303(a) and 303(b) is achieved and maintained by the use of said bore cone spacer 306. By employing said cone spacer 306, a minimum distance between said bearings 303 (a) and 303 (b) is maintained. No matter how much torque is applied to said nut 307. Said bore cone spacer 306 prevents excessive bearing load by maintaining proper distance between said bearings. Said bearing cannot be forced hard into bearing cups du to the bore cone spacer. The length of said cone spacer 306 shoul be within plus or minus 0.002" of the pre-measured distance betwee the seated bearing cups for the best results.

Bearing cups 304(a) and 304(b) (Timken cup # LL _^ 264610) are installed into bore grooves 308(a) and 308(b). Tapered roller bearing cones 303(a) and 303(b) (Timken cone # LL 264648) are placed into said bearing cups 304(a) and 304(b) with tapered sides facing each other at opposite ends of said pivot bracket assembly bore 302. Said bearings 303(a) and 303(b) allow said pivot bracke assembly 301 to engage in rotational movement shown as 202 in FIG 1. In FIG. 2B, clearance 702 should be measured similarly to the procedure shown in FIG. 8. Bearings should be temporarily seated in said bearing cups. The distance measured between said bearings is the length of the bore cone spacer to be used. This bore cone spacer measurement should be taken at several places around the bore to find an average. In the preferred embodiment, the

measurement between the bearings should be approximately 9.080".

Bearing cups 304(a) and 304(b) are placed in bore grooves 308(a) and 308(b) respectively. Said bore cone spacer 306 is placed between said bearing cups. Said bearing cone 303(a) shoul be placed on said barrel. It may be necessary to heat said beari cone to fit it on said barrel. Said barrel should be placed in said bore. Said bearing cone 303(b) is placed on said barrel and positioned in said bearing cup 304(b). Nut 307 is threaded onto said barrel thus locking said bearing and barrel in place. Said nut 307 may then be secured in place relative to said barrel.

Neoprene seals 305(a) and 305(b) may be positioned at each e of said barrel 310 to protect a seal from dirt, etc. Said neopre seals are approximately 1/4" thick and have a 16 3/8" inside diameter and a 19" outside diameter.

The foregoing description of the invention so fully reveals the general nature and the innovations and advantages of the invention that others can readily modify such invention and/or adapt it for various applications without departing from its general concepts, and, therefore such adaptations and modificatio should be and are intended to be comprehended within the meaning and range of the claims appended hereto and their equivalents, which claims define subject matter regarded to be the invention described herein.