US3304600A - Method of assembling a pair of railroad wheels and an axle - Google Patents

Description

Feb. 21, 1967 H. G. SPIER 3,304,600

METHOD OF ASSEMBLING A PAIR OF RAILROAD WHEELS AND AN AXLE Filed April 6, 1964 6 Sheets-Sheet 1 I/VVENTOR HANS G. SP/El? ATTORNEYS.

Feb. 21, 1967 H. G. SPIER METHOD OF ASSEMBLING A PAIR OF RAILROAD WHEELS AND AN AXLE 6 Sheets-Sheet 2 Filed April 6, 1964 ATTORNEYS.

Feb. 21, 1967 H. 3. SPIER METHOD OF ASSEMBLING A PAIR OF RAILROAD WHEELS AND AN AXLE Filed April 6, 1964 6 Sheets-Sheet 5 /NVE/VTOR HANS G. SP/ER ATTORNEYS.

Feb. 21, 1967 H. e. SPIER METHOD OF ASSEMBLING A PAIR OF RAILROAD WHEELS AND AN AXLE Filed April 6, 1964 6 Sheets-Sheet 4 R m M Q w m W m a m$ w A H Nm\ Q3 arMfM ATTOR/VE V5.

Feb. 21, 1967 H. cs. SPIER METHOD OF ASSEMBLING A PAIR OF RAILROAD WHEELS AND AN AXLE 6 Sheets-Sheet 5 Filed April 6, 1964 /92 a ms 200 ATTORNEYS.

Feb 21, 1967 H. G. SPIER 3,304,600

METHOD OF ASSEMBLING A PAIR OF RAILROAD WHEELS AND AN AXLE Filed April 6, 1964 6 Sheets-Sheet 6 EYMM ATTORNEYS.

United States Patent 3 304 600 METHOD OF ASSEMBlLIN A PAIR OF RAILROAD WHEELS AND AN AXLE Hans 'G. Spier, Media, Pa, assignor to Baldwin-Lima- Hamilton Corporation, Philadelphia, lPa., a corporation of Pennsylvania Filed Apr. 6, 1964, Ser. No. 357,431 3 Claims. (Cl. 29-168) This invention relates to a method of performing the complete assembly operation of new and refinished railroad wheel sets.

When service worn railroad wheels are replaced, new or refinished wheels are pressed onto new or used axles with a precisely specified press fit. This press fit must be closely controlled and recorded in order to insure that minimum safety requirements have been met. Otherwise, the wheels may come loose from their axles when they are put into service, and obvious disastrous consequences may result. Accordingly, the wheels and axles are individually worked, accurately coated with white lead on the press fit surfaces, and subsequently pressed into place under precisely recorded hydraulic force patterns which must be within specified limits. If this latter condition is not met, the wheel sets are again disassembled and reprocessed. This invention is specifically designed to carry out these operations in a completely automated sequence. It is obvious that the automation of the quantity as well as the quality of the required wheel replacing procedures will greatly simplify what has heretofore been a costly and time consuming procedure.

It is therefore the primary object of this invention to provide a method of performing the complete assembly operation of new and refinished railroad wheel sets.

A further object of this invention is to provide a method of carrying out the complete assembly operations of new and refinished railroad wheel sets under closely controlled conditions to insure that an accurate press fit is effected between the railroad wheels and their axles during assembly.

For the purpose of illustrating the invention, there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIGURE 1 is a diagrammatic top plan view of the railroad wheel and axle assembly station.

FIGURE 2 is a diagrammatic side view in elevation of the railroad wheel and axle assembly station shown in FIGURE 1 with certain portions shown in section for the purposes of illustration.

FIGURE 3 is a diagrammatic end elevational view of the railroad wheel and axle assembly station as seen from the righthand side of FIGURE 1 with certain portions shown in section for the purposes of illustration.

FIGURE 4 is a view similar to FIGURE 3 but illustrating the manner in which an axle is centered and held just prior to receiving the wheels in press fit.

FIGURE 5 is a view similar to FIGURES 3 and 4 but illustrating the manner in which the wheels are press fitted onto the previously centered axle.

FIGURE 6 is a top plan view of an axle white lead applicator comprising a portion of the railroad wheel and axle automatic assembly station.

FIGURE 7 is a cross sectional view taken substantially along the plane of line 77 of FIGURE 6.

FIGURE 8 is a cross sectional view taken substantially along the plane of line 8-8 of FIGURE 7.

FIGURE 9 is an end view in elevation of the axle white lead applicator as seen along the plane indicated by the line 9-9 of FIGURE 7.

FIGURE 10 is a top plan view of an axle holder and locating unit comprising a portion of the railroad wheel and axle assembly station.

FIGURE 11 is a cross sectional view taken substantially along the plane indicated by the line 1111 of FIG- URE 10.

FIGURE 12 is a side view in elevation of a wheel centering unit comprising a portion of the railroad wheel and axle assembly station.

FIGURE 13 is a cross sectional view taken substantially along the plane indicated by the line 13-13 of FIG- URE 12.

FIGURE 14 is a cross sectional view taken substantially along the plane indicated by the line 1414 of FIG- URE 12.

FIGURE 15 is a cross sectional view taken substantially along the plane indicated by the line 15ll5 of FIGURE 12 and illustrating a wheel centering roller.

General organization Referring now to the drawings in detail, and particularly FIGURES 15, a railroad wheel and axle automatic boring and assembly station is generally designated by the numeral 20.

The boring and assembly station 20 is adapted to transport freshly machined axles and their matching freshly bored wheels to a point of assembly. The axle wheel seats as well as the wheel bores are coated with a controlled amount of white lead and placed in an exact linedup position. The apparatus is then designed to press both wheels onto the axle in such a manner that the press fit and press force for each wheel can be individually controlled and recorded, as prescribed in an Ashton Wheel Press Recording Gauge manufactured by the Ashton Valve Company of Wrentham, Mass. The completed wheel set is then delivered to a dolly so that it can be rust-proofed and disposed of for use or storage after the recorded press fit characteristic has been inspected and found correct.

In accordance with the invention, a new or refinished wheel 22 is placed upon a conveyor track comprising a rail 30 and rolled to a pickup station 23. At the end of its travel upon the track 3d, a camming device 32 will contact the wheel 22 and tip it over into a horizontal disposition at the pickup station 23.

A pair of transfer crane arms 36 and 38 rotatably mounted upon the frame of the machine and having a hydraulic latch hook on their ends, are adapted to pick up a wheel 22 and position it in either of two wheel boring machines 40 and 42. That is, the crane arm 38 will pick up a wheel 22 and position it to the wheel boring machine 40 and the crane arm 36 will then pick up a wheel 22 and position it within the wheel boring machine 42.

The boring machines 40, 42 are fully disclosed in Patent No. 3,073,185, issued January 15, 1963, to Bernhard Hofimann. Accordingly, no further explanation is deemed necessary on these units except to mention that the bores in the wheels 22 are automatically centered, checked, and rebored to a diameter closely approximating the diameter of the wheel seats on the axle to which these wheels will be press fitted. The manner in which this is accomplished is fully disclosed in Patent No. 3,073,185.

Coordinated with the placing of the wheels 22 in the boring machines 40, 42, is the delivery of an axle 24 from an overhead conveyor dolly 46 to automatic wheel seat diameter measuring devices 84 and 86. The conveyor dolly 46 moves a refinished axle 24 in the conveyor trough 44 to a position wherein it is exactly centered with respect to a pair of parallel rails 50 and 52 extending longitudinally of the railroad wheel and axle assembly station 20. When this position is reached by the dolly conveyor 46, the conveyor trough 44 is tilted about a horizontal axis by means of a fluid cylinder 48 connected at one end to the trough 44 and at its other end to a bracket 54 suspended beneath the frame of the apparatus.

When the trough 44 is tilted, the axle 24 will roll along the spaced parallel rails 50, 52 until they abut a stop portion 62 on each of a pair of crank arms 56, 58 pivotably mounted on the rails 50, 52. The crank arms 56, 58 comprise an escapement device for feeding the axles 24 at spaced intervals to the Wheel seat diameter measuring devices 84 and 86. As shown in FIGURE 2, the rails 50, 52 slope gradually from the front to the rear end of the frame. Hence, the axles 24 will roll along the rails from the front to the rear portion of the frame. Upon activation, the cranks 56, 58 will be caused to pivot and send an axle 24 down the rails. At the same time, a succeeding axle will be seated within the seats 60 of the cranks 56, 58 ready to be subsequently delivered.

As an axle 24 rolls along the spaced rails 50, 52 it is centered so that the wheel seats 26 and 28 on the axle will be precisely positioned for measurement by the devices 86, 84, respectively. Hence, an axle centering device generally designated by the numeral 64 is mounted between .the rails 50, 52.

The axle centering device 64 includes a fluid cylinder 66 whose piston is connected to a crank arm 68. The crank arm 68 is pivotably mounted upon a shaft 70 extending between the rails. Secured to each end of the crank 68 is a link 72, 74. Pivotably connected to the link 72 is a block 76 slidablby mounted for reciprocation along the shaft 70. Similarly, pivotably connected to the link 74 is a block 78 slidably mounted upon the opposite end of the shaft 70 for reciprocation. A pair of opposed gripping plates 80 and 82 are mounted on the blocks 76, 78, respectively.

Therefore, at a predetermined time interval after release of the axle 24 from the crank arms 56, 58, the fluid cylinder 66 will be actuated to cause the block- s 76 and 78 to reciprocate along the shaft 70 towards each other. The gripping plates 80, 82 will grasp the ends of the axle 24 as it passes the centering unit 64 thereby aligning the wheel seats 26, 28 of the axle 24 with the wheel seat diameter measuring devices 86 and 84, respectively. After a finite time interval the axle 24 will be released by the gripping plate- s 80, 82 by retraction of the piston of the fluid cylinder 66 and the axle 24 will roll down the rails 50, 52 to the wheel seat diameter measuring devices. The units 84 and 86 are fully disclosed in Patent 3,073,185 and therefore a detailed explanation of these units is not necessary. It is sutficient to note that the units 86,-84 will precisely measure the wheel seat diameters 26, 28, respectively, and electronically transmit the exact diameter measurement of these wheel seats to the boring bar adjustments on the respective wheel boring machines 40, 42. With this information, the boring machines will bore each of the wheels 22 to the exact dimension necessary to effect a press fit of these wheels with one of the respective wheel seats 26, 28 on the axle 24.

After both wheels are bored to the required exact dimension, the wheels are alternately unchucked and picked up by one of the adjacent crane arms 36, 38 and moved to one of the stations 87, 89. From these stations, they are tipped to a vertical position by suitable mean-s (not shown) and they are rolled down a wheel track 92, sloped towards the rear of the station, into a wheel lifting and centralizing unit generally designated by the numerals 114 and 116 respectively.

At the same time, the axle wheel seat measuring devices 84 and 86 release a corresponding axle 24, which rolls over felt strip applicator-s of white lead positioned within the axle white lead application units 88 and 90 respectively, which are mounted adjacent the rails 50, 52. After being coated with white lead, the axle 24 continues its travel along the rails 50, 52 into an axle centralizing and lowering unit generally designated by the numeral 104.

The unit 104 aligns the wheel seats 26 and 28 on the 4 axle 24 with the centralized bores of the wheels 22 delivered to each of the stations 114, 116 and centralized by these stations.

As soon as both wheels 22 are in their centralized position as shown most clearly in FIGURES 3 and 4, a white lead swabber 188 and 190 pivotably mounted adjacent each wheel site on the frame of the apparatus is swung as shown by the dotted lines in FIGURE 1 into the hub bore of each of the wheels 22. These white lead swabbers are fully described in Patent No. 3,117,026, issued January 7, 1964, to Hans G. Spier. Therefore, a detailed explanation is not necessary. It is sufficient for the purposes of the present invention to note that each of the white lead swabbers 188, 190 include a white lead coated film disc wheel which will enter each of the hub bores in the railroad wheels 22 to deposit a white lead coating in these bores. After a time interval, the swabber devices 188, 190 swing back into the neutral positions shown in FIG- URE 1. It is important to coat the wheel seats 26 and 28 on the axle 24 as well as the bores of each of the wheels 22 with white lead in order to facilitate the pressing operation of the wheels onto the axle without scoring of the contact surfaces. Further, the white lead aids in the control of the tightness of the press fits, as well as providing a frictional lubricant desirable for removing the axle from the bored hole when required.

Referring now specifically to FIGURES 3-5, apparatus is disclosed for press fitting the wheels 22 within the wheel centralizing stations 114, 116 onto the wheel seats 28, 26 respectively of the axle 24.

The wheel centralizing units 114 and 116 are mounted upon wheeled dollys 120 and 118 respectively. These dollys are adapted to roll on spaced tracks 122 and 124 which extend transversely of the apparatus at the rear end thereof. The wheels are adapted to be press fitted upon the aligned axle 24 by means of a pair of press rams 126 and 128 mounted adjacent each one of the wheel centralizing stations 114 and 116. The mounting operation will be described more completely in the description which follows hereinafter. At this point, it is sufficient to note that in FIGURE 5, a press ram tube 130 actuated by the rams 126, 128 presses each wheel 22 onto its corresponding wheel seat on the axle 24.

While the wheels 22 are being press fitted upon the wheel seats of the axle 24, a gauge measures the pressures needed to seat the wheels upon the wheel seats of the axle and records them for final inspection of the finished wheel set.

After the wheels have been mounted upon the axle 24, the completed wheel set is removed by a dolly 174 mounted upon a pair of spaced tracks 176 and 178. After the ressing operation is completed, the dolly 174 is moved beneath the completed wheel set. Mounted upon the dolly 174 are a pair of axle supporting V- blocks 180, 182. After positioning of the dolly beneath the axle 24, adjusting screws 184 and 186 will raise the axle support V-blocks into supporting relationship with the completed wheel set. After the rams, wheel centralizing units, axle centralizing unit, and associated apparatus have been retracted, the dolly 174 can remove the completed wheel set to a desired location for disposition. If the pressure diagram recorded for a particular Wheel set indicates the required press fit has been made, the completed wheel sets will be stored for usage. Otherwise, the wheel sets will be reprocessed in accordance with the above description.

Axle white lead applicators Referring now specifically to FIGURES 6 to 9, atypical axle white lead applicator such as 88 is illustrated.

The white lead applicator 88 includes a trough 192 adapted to be filled with white lead 234. A shaft 208 extends through the walls of the trough 192. The shaft is rotatably mounted with respect to the trough in a pair of bearings 212 and 214 secured to opposite walls of the trough. Fixed to the shaft 208 are connecting sleeves 216 and 218. Welded or otherwise secured to the connecting sleeves is a felt pad support 194. A felt pad 196 is retained on the support 194. As shown most clearly in FIG- URES 6 and 8, the felt pad support 194 is bolted to a pivotable rail section 232 of the rail 50.

The trough 192 is mounted upon a stationary supporting structure such as 198 below the rail 50. A drain plug 200 extends from the bottom of the trough 192 through the stationary supporting structure 198.

Secured to the stationary supporting structure 198 is a motor support bracket 202. The motor support bracket 202 mounts an electric motor 204. The shaft 206 of the electric motor 204 is coupled by a coupling 210 to the rotatable shaft 208. A earn 222 is secured to the opposite end of the rotatable shaft 208. .A pair of switch actuators 224 and 226 are spaced about the circumference of the cam 222. These switch actuators are adapted to close a pair of microswitches 228 and 230 mounted upon the stationary support 198 on a Wall opposite from the wall mounting the motor bracket 202.

A counterweight 220 is mounted eccentrically upon the shaft 208.

The felt pad 196 has its top surface protruding approximately 4 above the top of the rail section 232. This is accomplished by fixing the rail section 232 relative to the felt pad 196 by bolting the support 194 to the rail section. Therefore, when an axle such as 24 gravitates down the spaced rails 50, 52 the seats will be coated with a deposit of white lead as it rolls by and contacts the felt pad 196.

After an axle 24 has passed by the rail section 232, the felt pad 196 may be recoated to condition it for its next application of white lead to a succeeding axle. This is accomplished by actuating the electric motor 204 to cause the shaft 208 to rotate in the direction of the arrow shown in FIGURE 8. The felt pad 196 will hence be dipped into the white lead disposed within the trough 192. As the shaft 208 rotates as shown in FIGURE 8, the cam 222 will rotate in a counterclockwise direction as shown in FIGURE 9. When the switch actuator 224 strikes the microswitch 228, the motor 204 will be shut down. The counterweight 220 will then return the felt pad to its upright postion as illustrated in FIGURES 7 and 8. When the felt pad 196 assumes its upright position, the cam 222 will be in a position wherein the switch actuator 226 will contact the microswitch 230. This will condition the motor 204 for operation after a finite time interval. This time interval is preset so that the motor 204 is activated only after the passage of a succeeding axle 24.

In the above described manner, the white lead deposit upon the felt pad 196 is automatically replenished.

Axle centralizing and lowering unit As previously discussed, an axle centralizing and lowering unit generally designated by the numeral 104 is adapted to lower the axle from the end of the rails 50, 52 and centrally locate it between the wheel centering stations 114 and 116.

The axle centralizing and lowering unit 104 includes a pair of parallel spaced rail portions 106 and 108 pivotably secured to the ends of the rails 52, 50, respectively. The pivotable rail portions 106 and 108 are connected by a transverse connecting bar 110. A fluid motor 102 has its piston pivotably connected to the connecting bar 110. The fluid motor is pivotably mounted upon the frame of the machine by a pair of spaced support arms 100 suspended from the rails 50, 52. Hence, upon retraction of the piston of the fluid motor 102, the rail portions 106, 108 can be lowered to position an axle 24 in alignment with the hub bores of the wheels 22 within the wheel centralizing stations 114 and 116, as shown in FIGURES 3 and 4.

Formed at the ends of the arms 106, 108 is an axle holding means generally designated by the numeral 112. One of the axle holding means is shown in FIGURES 10 and 11, and since the other axle holding means is identical, a description of one will sufiice.

Accordingly, the pivoted rail portion 108 is formed with an L-shaped end 240. Secured to the L-shaped end 240 are a pair of spaced parallel walls 236 and 238 of identical configuration. A bracket 242 is secured to the L-shaped end 240 intermediate the walls 236 and 238. The bracket 242 pivotably mounts a fluid motor 244. A pair of cranks 248 are pivotably secured to the piston rod 246 of the fluid motor 244. The cranks 248 are journalled upon a shaft 250 secured to the opposed walls 236 and 238.

A pair of cranks 254 and a pair of cranks 256 are pivotably mounted upon shafts 260 and 262 respectively secured to the opposite walls 236 and 238 on opposite sides of the cranks 248. The cranks 254 mount a roller 266 between them while the cranks 256 mount a roller 268 between them on a pin 274. The cranks 254 are connected to the cranks 248 by a connecting pin 272. The connecting pin 272 extends through the crank 254 into an elliptically shaped slot 273 in each of the cranks 248. Similarly, the pin 274 connects the cranks 256 to the cranks 248. The pin 274 is mounted Within an elliptically shaped slot 275 in the cranks 256.

A fourth pair of cranks 258 is rotatably mounted between the walls 236 and 238 by a shaft 264. At one of their ends, the cranks 258 are connected to the cranks 258 by a connector pin 276. The pin 276 extends into elliptical slot such as 277 in each of the cranks 258. At their ends remote from the pin 276, the cranks 258 rotatably mount a third roller 270 between them.

It will be noted from FIGURE 11, that the rollers 266, 268, and 270, form three points for grasping the circumference of the axle 24 shown in phantom lines. The circle defined by the points of tan-gency of the rollers 266, 268 and 270 can be varied by actuation of the fluid motor 244. That is, it will be readily observed that by extending the piston 246 from the position it occupies in FIGURE 11, the rollers 266, 268 and 270 will be urged into gripping engagement with the axle 24. Conversely, retraction of the piston 246 will open the gripping jaw formed by the rollers wider. Hence, the diameter of the axle holding means 112 can be varied to accommodate various sized axles which are to be assembled.

An end wall 252 is formed between the parallel walls 236 and 238 to rigidify the unit 112.

Wheel centering unit One of the wheel centering units is shown in detail in FIGURES 12-15. Since both the units 114, 116 are identical, the unit 114 has been selected for descriptive purposes.

The unit 114 is formed from a plurality of channelshaped frame members 278 secured together in a rectangular array. The frame members 278 are mounted upon a pair of spaced angle iron frame support members 280 and 282. Secured to each of the angle iron frame support members are a pair of spaced wheels 284 and 286, respectively. The angle iron frame members 280, 282 and wheels 284, 286 form a dolly such as 120 for moving the wheel centering unit 114 along the spaced tracks 122 and 124, as discussed previously.

Secured to one of theside channel-shaped frame members 278 is a bracket 288. Mounted upon the same frame member but spaced above the bracket 288 is a fluid motor support bracket 290. Pivotably mounted upon the bracket 288 are a pair of spaced cranks 294 and 296 connected by a pivot shaft 295 extending through the bracket 288. A fluid motor 292 is pivotably mounted upon the bracket 290. The piston of the fluid motor 292 is connected to a shaft 298. The shaft 298 is pivotably connected to opposed cranks 294 and 296.

Connected to the shaft 298 at opposite ends are a pair of parallel links 300 and 302. A pair of parallel links 304 and 306 are secured to the opposite end of the cranks 294 and 296. A shaft 308 connects the links 300 and 302 and also pivotably mounts a pair of parallel links 310 and 328. The links 310 and 328 extend on opposite sides of the side frame member 278.

A support plate 312 extends between the side frame members 278 adjacent their bottom. A slot 314 is formed in a central portion of the plate 312. A shaft 317 is disposed within the slot 314 and connects a link 318 and 320 to the link 310. Similarly, the shaft 316 connects the links 322 and 324 to the link 328.

A tong 326 is pivotally connected to the link 318. A tong arm 334 is pivotally connected to the link 320. A tong arm 330 parallel to the tong arm 326 is connected to the link 322. Similarly, a tong arm 336 parallel to the tong arm 334 is connected to the link 324. Mounted between the tong arms 334 and 336 is a roller 338. Mounted between the tong arms 326 and 330 is a roller 332.

A shaft 340 connects the parallel links 304 and 306 at one end thereof and also pivotally mounts link 342 on the link 304 as well as corresponding link 364 to the link 306. A support plate 358 which is channel-shaped in transverse cross section, is disposed between opposite channel shaped frame members 278 at the top thereof. The support plate 358 is secured to the bight of the frame members 278 by welding or the like. A pair of opposed vertically extending slots 360 are formed in the legs of the channel-shaped support plate 358. A shaft 344 extends through the parallel slots 360, connects the links 342 and 366 together. The shaft 344 also connects a pair of links 346 and 350 to the link 342. Similarly, shaft 344 connects a pair of links 362 and a link parallel to the link 350 (not seen) to link 366.

Pivotally connected to the link 346 is a tong arm 348. Pivotally connected to the link 350 is a tong arm 352. Similarly, the link 362 is pivotally connected to a tong arm 364 and the link parallel to the link 350 is connected to a tong arm parallel to the tong arm 352.

Rotatably supported between the tong arm 352 and its associated parallel tong arm is a roller 354. Rotatably mounted between the tong arm 348 and the tong arm 364 is a roller 356.

As shown in FIGURE 12, the rollers 332, 338, 354, and 356 are in their retracted position. That is, the piston of the fluid motor 292 has been fully retracted. This is the position of the rollers maintained as a wheel 22 is rolled down either of the tracks 92. Since the rollers are in their retracted position, a wheel gravi-tating down track 92 will roll over the lower left roller 338 shown in FIGURE 12 into the lower center of the device between rollers 338 and 332. A groove 368 is formed in each of the rollers The groove 368 on each of the rollers forms a seat for the wheel 22 and maintains it in a true vertical plane.

The wheels 22 are guided into the grooves 368 on the lower rollers and are prevented from tipping over when so seated by a guide and lateral support plate 98. The lateral support plate 98 comprises one parallel side of a four bar parallel linkage 96. The linkage may be mounted on the frame of the apparatus. The fluid motor 94 is connected to one of the substantially upright sides of the four bar linkage 96. Hence, upon retraction of the piston of the fluid motor 94, the support plate 98 will move linearly to the left as viewed in FIGURE 2 thereby enabling the dollys 120 and 118 to travel laterally of the frame of the machine. However, until it is time for the wheels to be pushed onto the wheel seats of the axle 24, the lateral support plates 98 remain active.

With the wheel 22 seated on the rollers 338 and 332, the fluid motor 292 may be energized to raise and centralize the wheel in the unit 114 and 116. That is, by extension of the piston of the fluid motor 292, the various linkage system described above will move the rollers 338, 332, 354, and 356 to the phantom position as shown in FIGURE 12. It should be noted that the tong arms form a lazy tong unit above and below the wheel which moves simultaneously towards the center of the unit 114. Accordingly, since the rollers 338 and 332 will move precisely the same distance as the rollers 354 and 356, the wheel 22 will be precisely centered with respect to the unit 114. This is so regardless of the size of the wheel being centered since movement of the top and bottom rollers towards each other will always be precisely the same amount.

Wheel mounting operation FIGURES 3 to 5 illustrate the manner in which the wheels 22 are press fitted onto the axle 24. As shown in FIGURE 3, the axle 24 has been dropped into alignment with the wheels 22 which in turn have been raised by the Wheel centering unit 114 and 116 to align with the axle 24.

Since the wheel mounting operation from either side of the axle is identical, only the mounting of the wheel 22 within the wheel centering unit 116 will be described.

A press ram tube support 132 is slidably mounted upon the framework of the machine. Pivotally secured to the framework of the machine at one of their ends and to the press ram tube support 132 at their opposite ends are a pair of parallel, vertically spaced press rams 126 and 128. Extending from the front face of the press ram tube support 132 is a press ram tube 130. Therefore, upon actuation of each of the press rams 126, 128, the press ram tube support 132 and its press ram tube will move towards the wheel 22 in the wheel centering unit 116.

An axle centering bar 134 is adapted to extend through each press ram tube 130 to push on both ends of the axle 24 and centrally locate it relative to the arms 106 and 108. This insures that the wheels will be press fitted precisely upon the wheel seats 26 and 28.

The centering bar 134 has a threaded end 138 threadably connected to a nut 136 mounted in the framework of the apparatus. The end of the nut 136 includes a bevel gear 150 disposed within a housing 148. A motor 140 is mounted upon the frame of the machine and includes a shaft 142 terminating in a bevel gear in mesh with the bevel gear 152.

Hence, upon rotation of the motor 140, the bevel gear 150 will cause the nut 136 to rotate by its connection with bevel gear 152. Since the nut 136 is stationarily mounted upon the machine frame, the centering bar 134 will be caused to travel linearly as shown in FIGURES 4 and 5. To insure that the centering bar 134 does not rotate, a key 166 secured to the centering bar 134 is slidably disposed in a keyway formed within the support 132.

Motion is transmitted to the centering bar adjacent the wheel centering unit 114 by an equalizing shaft 158 traversing the framework of the machine and having a pair of bevel gears 156 and 160 at oppposite ends thereof. The bevel gear 156 meshes with a bevel gear 144 on the shaft 142 of motor 140 and which is supported by a bearing 146. The gear 160 meshes with a bevel gear 162 supported by the bearing on the opposite side of the frame. The gear 162 is connected to a shaft 163 leading to a housing 164, the components residing therein being identical with the components within the housing 148. Hence, the motor 140 simultaneously moves the centering bars on each side of the axle towards the axle to center it.

The Wheel mounting operation proceeds substantially as follows:

The motor 40 is activated to move the centering bars to grip the ends of the axle 24 endwise. A spring biased center point at the end of each centering bar brings the axle in precision alignment with the centering bars and thus with the wheels and holds the axle in place. The centering bars 130 are extended through the hub bores in each wheel 22.

Simultaneously, the press rams 126 and 128 are activated to move the support 132 and the fixed press ram tube 130 towards the wheel 22. The rollers in each wheel centering unit 114, 116 firmly grip the roller and prevent the press ram tube 130 from laterally tilting the wheel with respect to its wheel centering unit. Upon contact of the press ram tube 130 with the wheel 22, the wheel centering units 114, 116 which are mounted upon the dollys 118, 120 will 'be moved towards the axle seats 26 and 28 on the axle 24.

Once the axle 24 is gn'pped endwise by the centering bars 134, the arms 106 and 108 release the axle 24 and swing further downward in order to clear the approaching wheels 22.

The Wheels 22 are then slid over the axle ends and onto their corresponding wheel seats as shown more clearly in FIGURE 5. Since it is practically impossible to provide exactly equal press fits for both wheels, a differential force to move the axle 24 endwise cannot be avoided. However, the strong holding force provided by the centering bars 134 and their associated supporting structure will prevent any endwise moving of the axle during the pressing operation. It should also be noted that any variation in the length of the axle 24 will not affect the correct final end wise location of the axle in relation to the wheels.

An Ashton Wheel Press Recording Gauge 168 is mounted on each of the dual press rams. This gauge can now accurately pick up the individual pressure and movement pattern causing the wheel 22 to seat upon a wheel seat of the axle. The gauge will record the pressure and movement pattern in the form of a pressure-time diagram which is used for final inspection of the finished wheel seat. As discussed previously, if the pressure needed to mount the wheels upon the Wheel seats of the axle is not within required limits, the completed wheel set will be disassembled and will be reprocessed.

The final distance between the press fitted wheels 22 is determined by a wheel distance gauge generally designated by the numeral 171. The wheel distance gauge 171 includes a pair of spaced microswitches 170 and 172, which automatically on contact with the wheels 22 terminates the pressing forces. These switches are activated when the proper distance between the wheels has been reached.

After the wheels 22 have been press fitted upon the axle 24, the press rams and press ram tubes are retracted, and the dolly 174 is brought forward to carry off the completed wheel set.

Operation To recapitulate, the operation of the railroad wheel and axle automatic boring and assembly station is substantially as follows:

A wheel 22 is placed upon a rail conveyor 30, tipped over, and delivered by a crane arm to one of the boring stations 49, 42. A succeeding wheel follows the same prescribed path and is delivered by a second crane arm to the empty one of the boring stations 40, 42.

Simultaneously, an overhead conveyor dolly 46 delivers an axle to an escapement device. The escapement device allows axles to gravitate down the sloped rails 50', 52 at predetermined spaced time intervals to an axle centering unit 64. When the axle is centered, it is released from the centering unit 64 and rolled to a pair of automatic wheel seat diameter measuring devices 84 and 86 positioned adjacent the rails 50, 52.

The devices 84, 86 electronically transmit the exact diameter measurement of the wheel seats 26, 28 on the axle 24 to the boring bar adjustment on the respective wheel boring machines 40, 42.

In the wheel boring machines, each of the wheels 22 are automatically centered, chucked, and bored to a dimension which will provide a press fit with the corresponding wheel seat on the axle 24.

After the wheels are bored to the exact dimensions required, the wheels are alternately unchucked and picked up by the respective crane arms 28, 36 and moved lid to stations 87, 89, respectively. At the stations, the wheels are tipped over into a vertical plane and are rolled down tracks 92.

At the end of the tracks 92 are a pair of wheel centering units 114 and 116. Centering rollers in said units are in their retracted position, whereby each wheel may enter the units and be seated upon a pair of spaced rollers. The wheels 22 so delivered, are prevented from tipping over and thus remain seated upon the rollers by a lateral support plate 98.

At the same time, the axle wheel seat measuring devices 84 and as release a corresponding axle, whose wheel seats are rolled over felt strip applicators 196 of white lead 234. The axle is then delivered into the axle centralizing and lowering unit 104.

The fluid motor 292 is then actuated to move the tong arms into a position in which the support rollers contact the wheel rim and lift the wheel into the design center of each wheel centering unit 114, 116, regardless of the size of the wheel. As soon as both wheels are in this position, the white lead swabber 190, at each Wheel site, swings by hydraulic or pneumatic action into a position where its white lead coated felt disc wheel enters the hub bore of the wheels 22 and deposits a white lead coating in the bore. After a time interval, the swabber devices 188, 1% swing back into their neutral positions, as shown in FIGURE 1.

The axle 24 is now held within the axle holding means 112 at the end of the axle centralizing and lowering unit 164. Upon actuation of fluid motors 244, the gripping rollers 266, 268 and 270 will be contracted uniformly towards the horizontal design center line of the axle holding means which will coincide with the axle center line regardless of the axle diameter. Then the fluid motor 102 is activated to cause the arms 1% and 108 to pivot to a lower position as seen in FIGURES 3-5. This position brings the axle center line into coincidence with the center line or centralized wheels 22.

The wheel centralizing units 114, 116 are mounted upon wheel dollys 120, 118 respectively. The wheels 22 are now guided accurately towards the axle 24 by the press rams 126, 128 on each side of the frame. These ress rams contact the wheel hubs with their press ram tubes 130. Simultaneously, a centering bar 130 closes in from each end of the frame and firmly holds the axle endwise. A spring biased center point at the end of each centering bar brings the axle 24 in precise alignment with the centering bars and thus with the wheels and holds the axle in place. The arms 166 and 108 of the axle lowering and centralizing unit 104 are now caused to pivot further downward, leaving the axle 24 clamped rigidly endwise. The arms 1% and 1158 move downward in order to clear the approaching wheel hubs 22.

The centering bars 134 move horizontally towards each axle end at an equal rate of movement and exactly equidistant from the vertical center line of the device. Hence, the centering bars, will exactly center the axle and position its wheel seats in precise relation to the advancing wheels 22. Further, any variation in the length of the axle will not affect the correct final endwise location of the axle in relation to the wheels.

The wheel hubs 22 are subsequently slid over the axle ends and are press fitted onto the wheel seats 26 and 28 on the axle 24. The Ashton Wheel Press Recording Gauges 168 accurately pick up the individual pressure and movement pattern of the press rams 126, 128 and record them in the form of a pressure-time diagram for final inspection of the finished wheel set.

The final distance between the press fitted wheels is controlled by microswitches 170, 172, which automatically on contact terminates the pressing forces when the proper distance between the wheels has been reached.

The final operation consists of advancement of the wheel set removal dolly 174 to a position underlying the central portion of the axle 24. The axle support V-blocks 1 l 180, 182 are raised vertically into supporting position with the axle 24. Then, the press rams 126, 128 and their press ram tubes 130 are retracted. At the same time, the centering bars 134 are retracted. The dolly 174 and finished wheel set assembly is moved to a desired location for disposition of the wheel set.

The sequencing of the described operations is initiated by suitably mounted contact switches and time relays at the end of each mechanical motion. Alternatively, the sequencing can be carried out by a suitably timed and adjusted rotating cam assembly, which operates electric contactors or air pilot valves for the initiation of each operation by allowing a normal time interval between each action sequence. Suitable feedback safety switches or air valves can be installed to prevent malfunctions.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

I claim:

1. A method of assembling a pair of wheels and an axle comprising the steps of conveying an axle to a position intermediate a pair of spaced wheels, aligning a bore in each wheel with the wheel seats on said axle so that their axes coincide, shifting said axle along its axes to position it equidistant from each of said wheels, simultaneously applying a pushing force to each of said wheels to press the wheel bores in said wheels onto the wheel seats of said axle, measuring and recording the pushing force applied to each wheel, and comparing said recorded force with a predetermined standard.

2. A method of assembling a pair of wheels and an axle comprising the steps of measuring the diameter of a pair of wheel seats on said axle, automatically causing a pair of wheels to be bored to a dimension closely approximating the measured diameter of said wheel seats, applying a protective coat of material to the wheel seats on said axle, conveying said axle to an assembly station, conveying said bored wheels to said assembly station in straddling relation to said axle, applying a protective coat of material to a bore in each of said wheels, aligning the bores in said wheels with the wheel seats on said axle so that their axes coincide, shifting said axle along its axis to position it equidistant from each of said wheels, simultaneously applying a pushing force to each of said wheels to press said wheel bores onto the wheel seats of said axle, measuring and recording the pushing force applied to said wheels and comparing said recorded force with a predetermined standard.

3. A method of assembling a pair of wheels, each wheel including a bore, and an axle including a pair of spaced wheel seats comprising the steps of conveying said axle to an assembly station intermediate and above a pair of spaced wheels, gripping said axle and lowering it to an assembly position, raising said wheel bores into alignment with the axis of said axle, shifting said axle along its axis to position it equidistant from each of said wheels, simultaneously applying a pushing force to each of said wheels to press said Wheel bores onto the wheel seats of said axle, limiting the final distance between said wheels, measuring and recording the pushing force applied to said wheels, and comparing said recorded force with a predetermined standard.

References Cited by the Examiner UNITED STATES PATENTS 2,446,621 8/1948 Thiry 29407 3,073,013 l/l963 Miller et a1 29l68 3,073,185 1/1963 Hotfmann 774 3,085,311 4/1963 Miller et al 2933 3,117,026 1/1964 Spier 118-215 JOHN F. CAMPBELL, Primary Examiner.

THOMAS H. EAGER, Examiner.

Claims (1)

1. A METHOD OF ASSEMBLING A PAIR OF WHEELS AND AN AXLE COMPRISING THE STEPS OF CONVEYING AN AXLE TO A POSITION INTERMEDIATE A PAIR OF SPACED WHEELS, ALIGNING A BORE IN EACH WHEEL WITH THE WHEEL SEATS ON SAID AXLE SO THAT THEIR AXES COINCIDE, SHIFTING SAID AXLE ALONG ITS AXES TO POSITION IT EQUIDISTANT FROM EACH OF SAID WHEELS, SIMULTANEOUSLY APPLYING A PUSHING FORCE TO EACH OF SAID WHEELS TO PRESS THE WHEEL BORES IN SAID WHEELS ONTO THE WHEEL SEATS OF SAID AXLE, MEASURING AND RECORDING THE PUSHING

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