US2792736A - Cam bar for axle lathes - Google Patents

Description

May 21, 1957 R. H. OSTER ET AL 2,792,736

CAM BAR FOR AXLE LATHE-S Filed June 7, 1951 2 Sheets-Sheet J.

' INVENTORS ROBERT H.0STER And THEYODORE AZSAMBOKY HIS ATTORNEY -May 21, 1957 R. H. OSTER ETAL 2,792,736

CAM BAR FOR AXLE LATHES Filed June 7, 1951 2 Sheets-Sheet 2 FIG. 3

INVENTORS ROBERT H. OSTER And HIS ATTORNEY United States Patent CAM BAR FOR AXLE LATHES Robert H. Oster, Library, and Theodore A. Zsamboky,

Pittsburgh, Pa., assignors to United States Steel Corporation, a corporation of New Jersey Application June 7, 1951, Serial No. 230,400

6 Claims. (Cl. 82-14) This invention relates to an improved cam bar for axle lathes.

In the manufacture of railroad car axles, an axle lathe is used to machine the central portion of each axle (i. e., the portion between the two wheel seats) from a forged condition to a smooth finish. Such lathes include a longitudinally movable carriage, one or more cutting tools which move longitudinally with the carriage, but which can move in and out with respect to the work independently of the carriage, and a cam bar for controlling this in-and-out movement. The present invention is concerned with an improved cam bar for a recently developed axle lathe that has three cutting tools, each of which cuts approximately a third of the machined length. In making each cut the carriage of such a lathe travels only about a third of this machined length, thus increasing the speed at which an axle can be machined by about threefold over a lathe having only a single cutting tool.

Standard axles have a cylindrical section at the longitudinal center, and tapered sections at each end of this cylindrical section extending toward the wheel seats. The

junctures between the tapered sections and the wheel seats are rounded. The variables in different standard designs of axles are (a) the length of the central cylindrical section, (b) the angle of taper of the tapered sections, (0) the radius of the rounded juncture between the tapered sections and the wheel seats, and (d) the total length which must be machined between the wheel seats. Prior to the present invention, the only way of which we are aware of machining different designs of axles necessitated a different cam bar for each design.

An object of the present invention is to provide an improved cam bar which is adjustable so that it can be used for machining axles of any standard design.

A more specific object of the invention is to provide an improved cam bar which includes a holder and different individual cams mounted therein which either are adjustable or are removable and replaceable to vary the configuration, so that the one cam bar can be used for machining all the standard designs of axles.

In accomplishing these and other objects of the invention, we have provided improved details of structure, a single form of which is shown in the accompanying drawings, in which:

Figure 1 is a somewhat schematic top plan view of an axle lathe of the type with which the cam bar of the present invention can be used;

Figure 2 is a horizontal sectional view of an improved cam bar which embodies features of the present invention;

Figure 3 is a vertical cross sectional view taken substantially on line IIIIII of Figure 2;

Figure 4 is a top plan view of an alternative fillet cam which can be used in place of the fillet cams shown in Figure 2; and

Figures 5 and 6 are top plan. views of alternative approach cams which can be. used, in place of the approach cams shown in Figure 2.

2,792,736 Patented May Figure 1 shows an axle lathe which includes a carriage A, three cutting tools 131, B2 and Ba, and a cam bar C. E represents an axle which is mounted in the lathe for machining. The lathe machines the two tapered sections X,- the central cylindrical section Y, and the rounded junctures Z of this axle. The carriage illustrated moves from right to left in making a cut and the axle rotates, although it is apparent that with an appropriate drive and cam arrangement the carriage could move the other way. The cam bar furnishes two fillet cams 10 and 12, two approach earns 13 and 14, two taper cams 15 and 16 and a center cam 17. The three cutting tools B1, B2 and B3 have rollers F1, F2 and F3 respectively which ride along these cams for guiding the tools in and out with respect to the axle as the carriage travels longitudinally.

Roller F1 is offset longitudinally to the right of its cutting tool; roller F2 occupies the same longitudinal position as its cutting tool; and roller F3 is offset longitudinally to the left of its cutting tool. At the start of a cut the left cam face of the fillet cam 10 guides tool B1 into the work, and the left cam faces of the approach cams 13 and 14 guide tools B2 and B3 respectively into the work. The fillet cam must provide for forming the rounded juncture Z at the right, but the two approach cams merely guide their tools into the work. Next the three tools make a cut with the taper cam 15 guiding the tool E1, the taper cam 15, center cam 17 and taper cam 16 successively guiding the tool B2, and the taper cam 16 guiding the toolBs. At the conclusion of this cut, the right cam faces of the approach earns 13 and 14 guide the tools B1 and B2 away from the work and the right cam face of the fillet cam 12 guides the tool B3 away. This fillet cam 12 must provide for forming the rounded juncture Z at the left. The longitudinal offset in the rollers F1 and F3 from their cutting tools B1 and B3 enables these tools to cut the portions of the axles directly opposite the approach cams 13 and 14 and this offset also furnishes the necessary overlap with the portion of the axle which tool B2 cuts. The details of the lathe apart from the improved cam bar are not shown, since per so they are not part of the present invention, but can be of any standard or desired construction.

With reference to Figures 2 and 3, the cam bar of the present invention comprises a holder 18 which is of U-shape in cross section. The bight of the U forms the back face of the cam bar (i. e., the face directed toward the work); the arms of the U form the top and bottom of the cam bar; and the open end of the U forms the front of the cam bar from which the various cams 10 to 17 project. These cams are formed as separate parts mounted within the holder 18, and each cam is of approximately half the thickness of the space within the holder. A plurality of bolts 19 affix the center cam 17 to the back of the holder. The center cam has an outside pair of pivot openings 20 and an inside pair of pivot openings 21. The two taper cams 15 and 16 extend from the center cam 17 toward the ends of the holder. They are pivoted to the center cam 17 on bolts or pins 22 that pass through either the openings 20, as illustrated in Fig ure 2, or else the openings 21, depending on the length of the cylindrical center section Y which is desired in the machined axles.

A plurality of abutment screws 23 are threadedly engaged with the back of the holder 18. Their inner ends abut the backs of the taper earns 15 and 16. Proper adjustment of these screws adjusts the angle of the taper cams about the pins 22 and consequently adjusts the angle of taper produced in the tapered sections X of the axle. Preferably the taper cams contain a plurality of slots 24 andthe sides of the holder 18 have screws, 25 which pass through said slots for frictionally clamping the taper cams in adjusted position.

The two fillet earns 10 and 12 are removably bolted to the outer end portions'of .the taper earns 15 and 16 on bolts 26. The back edges of the taper cams carry flanges 27 against which the fillet cams abut. The fillet cams illustrated have two sets of openings for receiving bolts 26 to furnish two different positions of adjustment. Other adjustments can be obtained by using fillet cams of different configuration, such as those illustrated in Figure 4. The selection and adjustment of the fillet cams controls the radius of the rounded junctures Z of the machined axle.

The two approach earns 13 and 14 are bolted to the taper cams intermediate the length of the latter on bolts 28 and they abut flanges 27 on the taper cams. These approach cams are removable and replaceable with cams of other configuration, such as those illustrated in Figures and 6, Selection of the approach cams and positioning of the fillet cams controls the machined length between wheel seats in the axle. The longer the approach earns, the shorter the machined length of the axle, since the approach cams withhold the cutting tools from the work. Thus the cams illustrated in Figure 2 are used for an intermediate machined length, while those illustrated in Figures v5 and 6 are used for shorter and longer machined lengths respectively. It is seen that moving the fillet cams farther out from the position illustrated in Figure 2 also increases. the machined length of the axle.

From the foregoing description it is seen that the present invention affords a cam bar which permits adjustability in the four variables encountered in standard designs of railroad axles. The proper selection and adjustment of cams enables a single cam bar to be used for machining any standard axle, thus eliminating the need for a different cam bar for every axle design. A further advantage in the adjustable cam bar is that it enables ready compensation for springing of the work or the lathe parts. All that is necessary to compensate for suchv springing is to adjust slightly the angle of taper of the taper cams 15 and 16.

While we have shown and described only a single embodiment of the, invention, itis apparent that modifica- .tionsmay arise. Therefore, we do not wish to be limited to the disclosure set forth, but only by the scope of the appended claims.

We claim:

1. A cam bar for multiple tool axle lathes comprising .an elongated holder, a center cam fixed to. themid-portion of said holder, a pair of taper cams pivoted to said center cam and extending therefrom toward the ends of said holder, adjustable. means carried by said holder for adjusting the angles of said taper cams, a pair of fillet cams removably carried by said taper cams at the outer end portions of the latter, and a pair of approach cams removably carried by said taper .cams intermediate the length of the latter, the cam faces of said fillet and approach cams overlapping those of the respective taper cams on which they are mounted, and the cam faces of said taper cams overlapping that of said center cam.

2'. A cam bar for multiple tool axle lathes comprising an elongated holder, a center cam fixed to the mid-portion of said holder, a pair of taper cams pivoted to said center cam and extending therefrom toward the ends of said holder, the pivot points being adjustable to vary the effective length of the center cam, adjustable means'carried by said holder and abutting said taper cams for adjusting the angles of the latter, a pair of fillet cams removably and replaceably carried by said taper cams at the outer end portions of the latter, and a pair of approach cams removably and replaceably carried by said taper cams intermediate the length of the latter, the cam faces of said fillet and approach cams overlapping 'those of the respective taper cams on which they are mounted, and the cam faces of said taper cams overlapping that of said cen ter cam.

3. A cam bar for multiple tool axle lathes comprising an elongated holder of U-shape in cross section, a center cam bolted to the inside mid-portion of said holder, a pair of taper cams pivoted to said center cam and extending therefrom toward the ends of said holder, the pivot points being adjustable to vary the effective length of said center cam, a plurality of abutment screws threadedly engaged with the back of said holder and abutting the backs of said taper cams for adjusting the angle of taper, a pair of fillet cams removably and replaceably carried by said taper cams at the outer end portions of the latter, and a pair of approach cams removably and replaceably carried by said taper cams intermediate the length of the latter, said center cam, said taper cams, said fillet cams and said approach cams all projecting from the open front of said holder, the cam faces of said fillet and approach cams overlapping those of the respective taper cams on which they are mounted, and the cam faces of said taper cams overlapping that of said center cam.

4. A cam bar for multiple tool axle lathes comprising an elongated holder of U-shape in cross section, a center cam bolted to-the inside mid-portion of said holder, a pair of taper cams pivoted to said center cam and extending therefrom toward the ends of said holder, the

pivot points being adjustable to vary the effective length of said center cam, a plurality of abutment screws threadedly engaged with the back of said holder and abutting the backs of said taper cams for adjusting the angle of taper, a flange along the back of each of said taper cams, a pair of fillet cams removably carried by said taper cams at the outer end portions of the latter and each abutting one of said flanges, and a pair of approach cams removably and replaceably carried by said taper cams intermediate the length of the latter and each abutting one of said flanges, said center cam, said taper cams, said fillet cams and said approach cams all projecting from the open front of said holder, the cam faces of said fillet and approach cams overlapping those of the respective taper cams on which they are mounted, and the cam faces of said taper cams overlapping that of said center cam.

5. A cam bar for multiple toolaxle lathes comprising an elongated holder of U-shape in cross section, a center cam. bolted to. the inside mid-portion of said holder, a pair of taper cams pivoted to said center cam and extending therefrom toward the ends of said holder, the pivot points being adjustable to vary the eifective length of said centercam, aplurality of abutment screws threadedly engaged with the back of said holder and abutting the backs of said taper cams for adjusting the angle of taper, said taper cams having a plurality of slots,.screws threadedly engaged with the sides of said holder and passing through said slots for clamping said taper cams in adjusted position, a'fl'ange along the back of each of said taper cams, a pair of fillet camsremovably and replaceably carried by said taper cams'at the outer end-portions of the latter and each abutting one of said flanges, and a pair of approach cams removably and replaceably carried by said taper cams intermediate the length of the latter and each abutting one of said flanges, said center cam, said taper cams, said fillet cams and'said approach cams all projecting from the open front of said holder, the cam faces of said fillet and. approach cams overlapping those of the receptive taper: cams on which they are mounted, and the cam faces. of said taper cams overlapping that of said center cam.

6. A cam bar as defined in claim 5 in which the cam faces of said taper cams are horizontally aligned and occupy approximately half the thickness of the inside of said'holder, and the cam faces- 0f said center cam,- said fillet cams andsaid approach 'carns a re horizontallyaligned and vertically offset from those of saidtapercams-and occupy the remainder of the thickness of the inside of said holder.

References Cited in the file of this patent ONeel June 9, 1925 Van Hamersveld Aug. 7, 1928 Allen Jan. 14, 1941 Himoff M Dec. 23, 1947 Houghtaling June 14, 1949 Cross et a1. Feb. 6, 1951

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