US3924541A - Side frame key assembly - Google Patents

Abstract

A side frame key assembly for a roller bearing unit mounted for relative vertical movement in a pedestal-type side frame comprises a one-piece angular key structure overlying a horizontal base portion of the frame and movably mounted in the key opening of the side frame and an extension spring underlying the horizontal base portion and releasably engaging spaced attachment portions of the key structure to complete a tie loop interlocking with the horizontal base portion to retain the key structure in position to react directly against the side frame when the roller bearing unit applies load force to the key structure.

Description

United States Patent MacDonnell et al. Dec. 9, 1975 SIDE FRAME KEY ASSEMBLY 3,831,531 8/1974 Wresch 105/221 K Inventors: Robert w. MacDonne, te; Otto 3,841,231 10/1974 Hhnsky 105/221 K A. Shander, Chicago Heights, both of I11. Primary ExaminerJOhn J. Love [73] Assignee: R. W. Mac Company, Crete, Ill.

[22] Filed: May 15, 1975 [57] ABSTRACT PP 577,736 A side frame key assembly for a roller bearing unit Related Application Data mounted for relative vertical movement in a pedestal- CO ti uaf t f S N 501067 A 27 type side frame comprises a one-piece angular key lf g 0 structure overlying a honzontal base portlon of the on frame and movably mounted in the key opening of the side frame and an extension spring underlying the hor- (g1 izontal base portion and releasably engaging Spaced [58] Fieid 221 R attachment portions of the key structure to complete a 103/221 tie loop interlocking with the horizontal base portion to retain the key structure in position to react directly [56] References Cited against the side frame when the roller bearing unit ap- UNITED STATES PATENTS plies load force to the key structure.

3,521,570 7/1970 Hasten, Jr. 105/221 K 15 Claims, 20 Drawing Figures US. Patent Dec. 9 1975 Sheet 1 of6 3,924,541

FIG.

FIG. 3

FIG. 6

Sheet 2 0f 6 U.S. Patent Dec.91975 Sheet 3 of6 3,924,541

10 FIG. 7

US. Patent Dec. 9 1975 Sheet 4 of 6 US. Patent Dec.91975 Sheet50f6 3,924,541

US. Patent Dec. 9 1975 Sheet 6 of6 3,924,541

PRIOR ART FIG. |8A

AOOQ x an: mwumhm LOAD (POUNDS X I000) FIG. |8B

an: mwmmkm LOAD (POUNDS X I000) SIDE FRAME KEY ASSEMBLY RELATED APPLICATION This application is a continuation-in-part of our pending application Ser. No. 501,067 filed Aug. 27, 1974, now abandoned, and entitled Side Frame Key Assembly. The disclosure of said application is hereby specifically incorporated herein.

BACKGROUND OF THE INVENTION In the case of railway car trucks that include pedestal-type side frames, it is conventional to provide a side frame key mounted on the side frame to project through a key opening for retaining the roller bearing unit against accidental escape in the event of a derailment. The conventional side frame key is a one-piece steel forging or casting bolted to a horizontal base portion of the side frame adjacent to the key opening. The mounting bolt arrangement is not dependable because the vibrations associated with normal operations frequently work the nut loose and allow the bolt to pop out. The key easily falls out once the bolt is gone.

Because of tolerance variations in the side frames the existing one-piece keys, even the keys with a top exten sion to engage above the key opening and the keys with a reverse bend at the rear can only transmit the usual vertical loads by reacting against the holding power of the bolt. Thus, the special bolted keys are still dependent on the bolt and the bolt is still subject to the vibration problem. In addition, the bolted keys are sometimes difficult to remove when required for maintenance purposes.

SUMMARY OF THE INVENTION In accordance with the present invention an improved side frame key assembly is provided for easier and more secure mounting on the side frame to solve the vibration problem, to transmit the high shock loads associated with a derailment directly into the side frame and to allow easy removability and replacement, thereby facilitating the truck maintenance operations.

The improved key assembly for preventing accidental escape of a roller bearing unit mounted for relative vertical movement in a pedestal-type side frame that includes a vertical side wall having a horizontal base portion projecting away from the roller bearing unit, said vertical side wall having a generally rectangular key opening facing a lower peripheral region of the roller bearing unit, the key opening bordered by a front base comer portion and a top corner portion of the side wall, said key assembly comprising an angular body having a retainer portion to project outwardly of the key opening and border the lower peripheral region of the roller bearing unit and having a rearwardly projecting lever portion to.overlie the horizontal base portion, said body presenting direct keying means to fulcrum against the front base corner portion and remote keying means to engage a second side frame portion spaced from the front base comer portion, said body having spaced attachmentportions, and locking loop means to underlie the horizontal base portion and engage said attachment portions to complete a .tie loop interlocking with the horizontal base to retain the body in movable relation to enable both said keying means to react directly against the side frame when the roller bearing unit applies load force to the retainer portion.

In the presently preferred embodiments, the locking loop means is in the form of a tension spring that engages the key structure adjacent opposite extremities of the horizontal base portion of the side frame. The spring is not further stressed, once the key structure engages the side frame in load transmitting relation.

In one form, the one-piece key structure is elongated to present, at one end, a direct keying means in the form of a retainer portion that fulcrums on a front base corner portion bordering the bottom of the key opening and to present, at the other end, a remote keying means in the form of a reverse bend portion that interlocks with a rear base corner portion of the side frame. The locking spring is permanently attached to a front hook portion that depends from the retainer and is releasably attached to a rear hook that depends from the reverse bend position.

The key structure is also provided with a depending stub that seats in the existing bolt hole in the base to retain the mounted position of the key body.

In other forms, the one-piece key body includes either a top extension portion that serves as a remote keying means that directly engages a top corner portion bordering the key opening or lateral extensions that serve as remote keying means that directly engage rear edges of the side frame. In these forms, the key includes the direct keying means in the form of a retainer portion that fulcrums on a front base corner portion bordering the bottom of the key opening and a lever portion that carries a depending rear hook for releasably securing a locking spring that is permanently attached to a front hook that depends from the retainer portion.

The lever portion may be either in the form of a reverse bend to interlock with the rear base corner portion or in the form of a depending flange located alongside the rear base comer portion. A depending stub seating in the bolt hole in the base again serves to retain the mounted position of the key body.

The side frame key assembly is arranged to be applied in the train yard the same as brake shoes or other yard type repairs, thus eliminating the expense of shopping the car as is now the case. Equally important is the fact that the problem of missing roller bearing keys should gradually be eliminated since key replacements can now be made as part of the train yard program.

Eliminating the need for mounting bolts reduces the installation labor both as respects applying the bolts and as respects removing or burning off the bolts when changing wheels.

The locking spring feature keeps the key structure in proper position at all times to positively protect against vibration effects and its design eliminates the need for special handling tools.

The strength of the preferred side frame key embodiments and the resilient mounting relationship achieved for parts that are easy to remove and replace and the fact that the spring is not subjected to the actual load forces insures a long useful life.

Other features and advantages of the invention will be apparent from the following description and claims, and are illustrated in the accompanying drawings which show structure embodyingfeatures of the present invention and the principles thereof.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings forming a part of the specification and in which like numerals are employed to designate like parts throughout the same:

FIG. 1 is a fragmentary, transverse sectional view, showing a conventional pedestal-type side frame and roller bearing unit in conjunction with a side frame key assembly of this invention employing a one-piece angular key structure.

FIG. 2 is an end view showing the key assembly in mounted position.

FIG. 3 is a bottom plan view of the angular key structure.

FIG. 4 is a transverse sectional view, similar to FIG. 1, showing a modified embodiment.

FIG. 5 is an end view of the embodiment of FIG. 4.

FIG. 6 is a transverse sectional view similar to FIG. 4 and showing another embodiment.

FIG. 7 is a transverse sectional view similar to FIG. 6 showing another embodiment.

FIG. 8 is an end view of the embodiment of FIG. 7.

FIG. 9 is a transverse sectional view similar to FIG. 1 showing a streamlined embodiment.

FIG. 10 is an end view of the embodiment of FIG. 9.

FIG. 11 is a bottom plan view of the embodiment of FIG. 9.

FIG. 12 is a transverse sectional view illustrating insertion of the FIG. 9 key into the key opening.

FIG. 13 is a transverse view illustrating engagement of the spring to interlock the FIG. 9 key in mounted position.

FIG. 14 is a transverse sectional view similar to FIG. 1 and showing another streamlined embodiment.

FIG. 15 is a bottom view of the key shown in FIG. 14.

FIG. 16 is an end view of the embodiment of FIG. 14.

FIG. 17 is a fragmentary section showing a spring provided with a wear sleeve.

FIG. 18 is similar to FIG. 14, but shows a prior art key.

FIGS. 18A and 1813 give test data on the prior art keys of FIG. 18.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to the drawings a conventional railway car truck arrangement is shown as including a pedestaltype side frame designated generally at 10 which is supported on a roller bearing unit 11. The side frame has vertical pedestal walls flanking the roller bearing unit 11 and normally allowing relative vertical movement between the roller bearing unit and the side frame for accomodating disassembly. The side frame wall 12 has a conventional key opening 13 and is shown to terminate in a horizontal base portion 14 that is typically provided with a hole 15 for an anchor bolt such as is used with prior art type side frame keys.

The improved side frame key of this invention uses a one-piece angular keying structure 16 in conjunction with a locking loop means that is shown here in the form of a tension spring 17. The spring 17 underlies the base 14 and is connected to spaced portions of the key structure to form a tie loop that interlocks with the base portion 14. The keying structure is mounted for limited movement in the key opening 13 and has direct and remote keying means l8, 19, positioned for direct engagement with spaced apart portions of the side frame to transmit load forces directly into the side frame. The direct keying means 18 serves as the actual bearing contacting and retaining portion and is freeto fulcrum on the front base corner portion 14F. The remote keying means 19 is in the form of a reverse bend portion that embraces and interlocks around the rear base corner 14R to transmit loads upwardly into the base by 4 reason of the fulcrum action of the direct keying means Limited movement of the keying means 18, 19, as provided by the action of the locking spring 17 insures that the keying structure remains in proper position in the key opening 13 and establishes direct load transmitting engagement in spite of numerous dimension and profile variances in the different base walls and key openings that are encountered. Load forces applied to the key structure in connection with its function of retaining the roller bearing unit 11 are transmitted by fulcrum action of the direct keying means 18, the primary load being transmitted directly into the front base corner portion 14F and the reaction load being transmitted through the remote keying means into the rear base corner portion 14R.

It should be noted that the load transmitting action of the angular keying structure is insured by the presence of the locking spring 17, which permits simultaneous engagement at both the front and rear base corner 10- cations; however, the locking spring is not itself subjected to the actual load forces. In the illustrated embodiments the locking spring 17 is in the form of a stainless steel wire extension spring having a connecting loop 17F at the front end and a connecting loop 17R at the rear end. The front loop 17F is permanently secured in the eyehole of a front hook portion 18H that depends centrally from the retainer portion. The rear loop 17R is releasably engaged upon a rear securement hook 19H carried at the extremity of the remote keying means 19 and located beneath the base 14 to provide adequate clearance for the spring. When the spring 17 is in place it is in an elongated tension state, and applies a holding force of about 50 pounds to retain the key structure in proper position.

During normal operating conditions the usual vibration effects encountered will not dislodge the spring 17 nor will the spring allow vibrations to disengage the key structure from its proper position and orientation. Thus, when load froces are applied, whether vibration effects are present or not, both the direct and the remote keying means are in simultaneous engagement with the base to distribute the load directly into the front and rear base corners of the side frame.

The one-piece angular key structure 16 has a substantially plate-like, full length horizontal main wall 16M overlying the base to serve as a lever portion carrying the remote keying means in contact with the rear base corner and carrying the forwardly projecting retainer portion 18 in position to border the lower peripheral region of the roller bearing unit 11 to prevent the roller bearing from dropping out of the pedestal window of the side frame. The angular key structure 16 may be of any configuration suitable for casting or forging. In the illustrated embodiment, the main wall 16M has a tapering plan profile to merge at the front with the relatively wide retainer portion 18 and to merge at the rear with the relatively narrow u-shaped portion 19. The region of the merger of the main wall 16M with the retainer presents downwardly facing shoulderlSD that serve as the direct keying means that is to fulcrum on the front base corner 14F. The retainer portion has inwardly facing shoulders 181 spaced from the corner portion 14F to permit insertion of the key body. The retainer portion presents a contact face that is generally arcuate in side profile to provide a broad contact area in close clearance with the roller bearing unit. The main wall 16M has a beveled upper face to present a peaked, gently sloping top. The main wall has a concave central underface region that is provided with a depending stub 168 that fits loosely in the existing bolt hole to retain the desired key orientation.

It should be noted that the key structure seats in snug, limited clearance relation upon the side frame base and is positively seated by the action of the spring to maintain a positive mechanical interlock that is totally resistant to vibration effects while allowing the key structure to adapt to variances at the mounting location as required to establish simultaneous load transmitting engagement for both the direct and the remote keying means.

The procedure for mounting the side frame key assembly in installed position as shown in FIG. 1 is simple. The key body 16, with the spring 17 attached at the front, is inserted by feeding the free end of the spring through the key opening 13 from the rear side followed by the key structure which is held in the right hand with its retainer and tipped slightly upwardly. When the retainer projects partly through the key opening and the stub 16S passes over the rear base corner, the key structure is progressively rotated back to horizontal position and settled into place. The stub 165 contacts the top surface of the base when the key is forwardly inclined during insertion or removal. Its bottom face is rearwardly bevelled to facilitate insertion and removal. There is sufficient clearance to permit rapid insertion but the movement sequence must be accurate because the clearances are close. The locking spring 17 is then extended sufficiently to draw its rear loop 17R over the securement hook 19H. A pointed bar is suitable for the purpose.

A modified embodiment is shown in FIGS. 4 and 5 wherein the key body is essentially the same, as described, but in addition, the main body 16M of the onepiece key structure is shown as including an auxiliary remote keying means in the form of a pair of integral top extensions 16T arranged on opposite sides of the key opening in position to contact the lateral corner portions 14L and/or the top corner portion 14T of the key opening 13. In FIG. 5 a slight clearance is shown between the extensions 16T and the corner portions 14L, 14T because the variances in the key opening and base dimensions are such that it is not possible to assure simultaneous contact with both of the direct and remote key means 18, 19 and, in addition, of the auxiliary remote keying means.

The extensions 16T are provided as a temporary interlock in the event the remote keying means 19 were broken, but under these conditions the spring would necessarily be disengaged and the key would be subject to loss.

Another modification is shown in FIG. 6 wherein a single, centrally located integral top extension 16T' is provided on the main body to act as a primary remote keying means operating in conjunction with the direct keying means 18 to simultaneously engage spaced portions of the side frame in load transmitting relationship In FIG. 6, an angled rear portion 19 extends alongside the rear base corner and terminates in a rear securement hook 19H that receives the rear loop 17R of the tension spring. The rear portion 19' does not provide an interlock and thus may be of reduced thickness and width. The rear portion is only subjected to the spring load and is movable to enable the top extension and the direct keying means 18 to establish simultaneous engagement in spite of variances in the key open- 6 ing and base dimensions that are necessarily encountered.

Another modification is shown in FIGS. 7 and 8 wherein a pair of integral lateral extensions 16L are provided on the main body 16 to act as remote keying means to engage rear edge portions of the side frame.

As best seen in FIG. 7 and angled rear portion 19" extends in clearance relation to the rear base corner portion and the retainer portion 18" has a streamlined profile to project from the key opening 13 in clearance relation to the front base corner portion 14F.

The main body 16 has a depending stub or locator post that fits in the hole 15 in limited clearance relation to locate the mounted position of the key body.

The extension spring 17 as shown in installed position, has a front loop 17F engaged in the eye of a depending hook portion 1811" that depends from the retainer portion 18 in clearance relation to the front corner portion and a rear loop 17R engaged in the depending rear hook 1911 that is carried at the rear of the lever portion in clearance relation to the rear corner portion. The extension spring 17 has a pull loop 17L at its rear end that is engageable by a pointed bar or screw driver for extending the spring sufficiently to engage the rear loop 17R over the rear hook 19H" for locking the key in place.

The spring 17 would allow the key to shift sideways but such movements are limited by engagement of the locator post in the hole.

A further embodiment of the invention is shown in FIGS. 9 to 13, this embodiment being suitable for manufacture as a steel casting of M-20l Grade B material or as a casting of alumin um-zinc-magnesium alloy or as a carbon steel forging of M-126, Grade A material.

The key assembly, as shown in its installed position in FIG. 9, 10 and 11 has a key body 116 that includes a rearwardly extending lever portion terminating in a reverse bend portion 119 that extends in clearance relation around the rear base corner portion 14R and terminates in a depending hook 11911 and has a forwardly projecting streamlined retainer portion 118 that has a depending hook portion 11811 in substantial clearance relation to the front base corner portion 14F and providing a spring mounting eye.

The key body 116 includes a central depending stub 1168 that tits in limited clearance relation in the bolt hole 15 to locate the mounting position of the key.

The retainer portion 118 has a flat downwardly facing surface to serve as direct keying means that fulcrums on the front corner 14F and the reverse bend portion 119 has forwardly and upwardly facing surfaces to serve as remote keying means that interlocks with the rear comer 14R.

The extension spring 117 has a front loop 117F engaged in the hook portion 1181i and a rear loop 117R engaged in the hook portion 119H to form a tie loop interlocking with the horizontal base 14 to retain the key body in movable relation and enable both keying means to react directly against the side frame when the roller bearing unit 11 applies load force to the retainer portion.

Limited movement of the key body is accomodated by the provision of mounting clearances sufficient to allow for any side frame tolerance variations that may be encountered. The spring readily accomodates such limited movement so that the load forces do not act upon the spring but are transmitted by the key directly into the side frame.

At best seen in FIG. 11, the spring includes a pull loop 1l7L at the rear to facilitate engagement of the spring with the key.

The insertion and engagement of the key is illustrated in the sequence views of FIGS. 12 and 13. The key is oriented as shown in FIG. 12 to feed the spring 117 and the retainer portion 118 forwardly through the keyhole. The stub 116$ contacts the base during insertion and may be beveled to facilitate entry into the bolt hole 14 to the FIG. 13 position, wherein the stub is in limited clearance in the bolt hole.

In this embodiment, the streamlined configuration of the retainer portion 118 permits the depending hook I 18H to be longer to locate the spring more nearly horizontal and more directly aligned with the rear hook 1191-1. The intermediate turns of the spring react against the underface of the base 14 to hold the key in its seated position as illustrated. Larger diameter spring wire stock can be utilized to achieve a snug fit against the base and to accommodate any wear resulting from contact between the spring and the base.

With the key in place as shown in FIG. 13, the spring interlock is secured by inserting a pointed bar B through the pull loop 117L to wedge the bar against the lower external corner on the reverse bend portion 1 19. The bar is swung counter-clockwise to force the rear spring loop 117R over and onto the hook portion 119H. When the spring is seated, the bar is withdrawn and the key is locked in position as shown in FIG. 9.

For removal, the bar is inserted through the pull loop, wedged against the key and swung counter-clockwise and then pulled downwardly sufficiently to free the loop 117R from the the hook 1191-1. The retainer portion of the key is then lifted upwardly until the stub 116S clears the bolt hole 15 to allow the key to be pulled back.

A comparative test of a key constructed according to FIG. 1 with a key constructed according to FIG. 9, where both keys were subjected to static vertical loading applied to the retainer portions, showed that the streamlined embodiment carried about per cent greater load than did the FIG. 1 embodiment prior to fracture. In both tests, the fracture occurred at the transverse region of the key overlying the front corner 14F of the base.

The tested keys were constructed substantially to the proportions shown in FIGS. 1 and 9 where the scale is determined on the basis that the total end to end key length is 6 inches. It is believed that the streamlined embodiment of FIG. 9 may provide greater strength against vertical loading of the retainer portion because the streamlined retainer region merges with the main body without creating any localized stress pattern such as the shoulder 181 in FIG. 1 would introduce.

It should be noted that the disclosed embodiment of FIGS. 1 and 9 present a retainer portion having a bearing contact surface that extends along a 45 angle. The bearing contact surface may be slightly curved or substantially straight and the 45 angle enables the retainer to establish essentially the same clearance relation to the bearing for an entire range of bearing sizes.

A preferred embodiment is shown in FIGS. 14 to 16 where the key is shown in proportion on a scale where the total end to end key length is 6 inches.

In this embodiment, the key body 216 is provided with integral side wings 216W in place of the location post. The wings have a span of 2% inches to fit with limited clearance between the pedestal side walls to cooperate with the hood 219 in maintaining the desired key alignment.

The omission of the locating post enhances the keys ability to fit all existing truck applications, even including rebuilt trucks where the bearing is located at a slightly lower position relative to the side frame.

The bearing contact surface is again shown at a 45 angle and at a position to establish substantially uniform clearance for all bearing sizes.

Thus, with the retainer portion 218 being streamlined and with the locating post being eliminated, the key shown in FIGS. 14 and 16 is of maximum strength for resisting vertical loads and is of maximum versatility to fit all side frame conditions and achieve substantially uniform clearance for various sizes of bearings and wheels.

An improved spring assembly for use in any of the disclosed embodiments is shown in FIG. 17, wherein an extension spring 17 is shown provided with a wear sleeve 17W, preferably of polyurethane or other suitable. material, to accommodate contact and vibration effects between the intermediate coils of the spring and the side frame base.

FIG. 18 shows a key constructed exactly to the proportions of the key shown in FIG. 5 of US. Patent No. 3841231 on the basis that the flange 50 is 3 A inches by inches in size. The only difference between the FIG. 18 key and the prior art key of US. Pat. No. 3841231 is the provision of a horizontal top surface on the retainer to allow for convenient application of vertical loads.

Two samples of the FIG. 18 key were made and tested to determine the effect of the hook for preventing the bolt from being subjected to any stress due to vertical loads applied to the retainer portion.

Strain gauges were provided at the locations labeled 1, 2, 3 and 4. The gauge at location 1 gives readings for the hook stresses and these are represented by curve 111 in FIG. 17A. The gauges 2 and 3, together, give the readings of the average loading on the bolt. The gauge 4 gives readings to show changes in stress at the hook.

In each test, the key was secured by torquing the nut and bolt to 250 foot-pounds to provide preload in accordance with A.A.R. requirements.

Test results (based on strain gauge readings) on one sample are given in the graph of FIG. 18A where the curve B shows the load conditions at the bolt and the curve H shows the load condition at the hook.

Test results on a second sample are given in the graph of FIG. 18B where B shows the load condition at the bolt and H shows the load condition at the hook.

It appears that the bight-like form of the hook is unable to prevent loading of the bolt because the initial hook engagement is necessarily reduced when the bolt and nut assembly is given the required pre-loading.

Thus, while preferred constructional features of the invention are embodied in the structure illustrated herein, it is to be understood that changes and variations may be made by those skilled in the art without departing from the spirit and scope of the appended claim.

What is claimed is:

1. A side frame key assembly for preventing accidental escape of a roller bearing unit mounted for relative vertical movement in a pedestal-type side frame that includes a vertical side wall having a horizontal base portion projecting away from the roller bearing unit, said vertical side wall having a generally rectangular key opening facing a lower peripheral region of the roller bearing unit, the key opening bordered by a front base corner portion and a top corner portion of the side wall, said key assembly comprising angular keying structure overlying the horizontal base portion and freely movable in the key opening and having direct keying means to fulcrum against said front base corner portion and remote keying means for abutment against a spaced apart side frame portion, said key structure having a rearwardly projecting lever portion overlying said base portion and an outwardly projecting retainer portion bordering the lower peripheral region of the roller bearing unit, and locking loop means underlying the horizontal base portion and releasably engaging between spaced attachment portions of the key structure to complete a tie loop embracing the horizontal base portion to retain the key structure in movable relation to enable both said keying means to react directly against the side frame when the roller bearing unit applies load force to the retainer portion.

2. A side frame key assembly as defined in claim 1 wherein one of the attachment portions depends from the retainer portion and the other attachment portion depends from the lever portion and wherein said locking loop means is an extension spring.

3. A side frame key assembly as defined in claim 1 wherein said key structure includes a depending central stub for seating in an existing bolt hole in said base portion to determine the mounting position of the key body. i i

4. A side frame key assembly as defined in claim 1 wherein said lever portion carries a rear reverse bend portion to interlock with a rear base corner portion of the side frame and serve as the remote keying means.

5. A side frame key assembly as defined in claim 4 wherein said lever portion includes a depending central stub for seating in an existing bolt hole in said base portion to determine the mounting position of the key body.

6. A side frame key assembly as defined in claim 4 wherein one of the attachment portions depends from the retainer portion and the other attachment portion depends from the lever portion and wherein said locking loop means is an extension spring.

7. A side frame key assembly as defined in claim 4 wherein one of said attachment portions depends from the retainer portion and the other attachment portion 10 depends from the reverse bend portion and wherein said locking loop means is an extension spring.

8. A side frame key assembly as defined in claim 4 wherein said lever portion carries a top extension in clearance relation to the top corner portion of the key opening to act as an auxiliary interlock.

9. A side frame key assembly as defined in claim 1 wherein said lever portion carries a top extension to serve as the remote keying means and engage with the top corner portion of the key opening simultaneously with the engagement of the direct keying means with the base corner portion.

10. A side frame key assembly as defined in claim 1 wherein said lever portion carries lateral extensions to serve as the remote keying means'and engage with rear edge portions of the side frame simultaneously with the engagement of the direct keying means with the base corner portion. and wherein one of said attachment portions depends from the retainer portion and the other attachment portion depends from the lever portion and wherein said locking loop means is an extension spring.

11. A side frame key assembly as defined in claim 1 wherein said lever portion includes laterally projecting wings to fit with limited clearance relation in the side frame for maintaining key alignment.

12. A side frame key assembly as defined in claim 1 wherein one of the attachment portions depends from the retainer position and the other attachment portion depends from the lever portion and wherein said locking loop means is an extension spring reacting upwardly against said base portion to bias said keying structure downwardly against said horizontal base portion.

13. A side frame key assembly as defined in claim 1 1 wherein one of the attachment portions depends from the retainer portion and the other attachment portion depends from the lever portion and wherein said locking loop means is an extension spring reacting upwardly against said base portion to bias said keying structure downwardly against said horizontal base portion.

14. A side frame key assembly as defined in claim 7 wherein said retainer portion is of streamlined configuration and said extension spring reacts upwardly against said base portion to bias said keying structure downwardly against said horizontal base portion.

15. A side frame key assembly as defined in claim 12 wherein said extension spring is disposed within a wear sleeve of non-metallic material.

Claims (15)

1. A side frame key assembly for preventing accidental escape of a roller bearing unit mounted for relative vertical movement in a pedestal-type side frame that includes a vertical side wall having a horizontal base portion projecting away from the roller bearing unit, said vertical side wall having a generally rectangular key opening facing a lower peripheral region of the roller bearing unit, the key opening bordered by a front base corner portion and a top corner portion of the side wall, said key assembly comprising angular keying structure overlying the horizontal base portion and freely movable in the key opening and having direct keying means to fulcrum against said front base corner portion and remote keying means for abutment against a spaced apart side frame portion, said key structure having a rearwardly projecting lever portion overlying said base portion and an outwardly projecting retainer portion bordering the lower peripheral region of the roller bearing unit, and locking loop means underlying the horizontal base portion and releasably engaging between spaced attachment portions of the key structure to complete a tie loop embracing the horizontal base portion to retain the key structure in movable relation to enable both said keying means to react directly against the side frame when the roller bearing unit applies load force to the retainer portion.

2. A side frame key assembly as defined in claim 1 wherein one of the attachment portions depends from the retainer portion and the other attachment portion depends from the lever portion and wherein said locking loop means is an extension spring.

3. A side frame key assembly as defined in claim 1 wherein said key structure includes a depending central stub for seating in an existing bolt hole in said base portion to determine the mounting position of the key body.

4. A side frame key assembly as defined in claim 1 wherein said lever portion carries a rear reverse bend portion to interlock with a rear base corner portion of the side frame and serve as the remote keying means.

5. A side frame key assembly as defined in claim 4 wherein said lever portion includes a depending central stub for seating in an existing bolt hole in said base portion to determine the mounting position of the key body.

6. A side frame key assembly as defined in claim 4 wherein one of the attachment portions depends from the retainer portion and the other attachment portion depends from the lever portion and wherein said locking loop means is an extension spring.

7. A side frame key assembly as defined in claim 4 wherein one of said attachment portions depends from the retainer portion and the other attachment portion depends from the reverse bend portion and wherein said locking loop means is an extension spring.

8. A side frame key assembly as defined in claim 4 wherein said lever portion carries a top extension in clearance relation to the top corner portion of the key opening to act as an auxiliary interlock.

9. A side frame key assembly as defined in claim 1 wherein said lever portion carries a top extension to serve as the remote keying means and engage with the top corner portion of the key opening simultaneously with the engagement of the direct keying means with the base corner portion.

10. A side frame key assembly as defined in claim 1 wherein said lever portion carries lateral extensions to serve as the remote keying means and engage with rear edge portions of the side frame simultaneouSly with the engagement of the direct keying means with the base corner portion, and wherein one of said attachment portions depends from the retainer portion and the other attachment portion depends from the lever portion and wherein said locking loop means is an extension spring.

11. A side frame key assembly as defined in claim 1 wherein said lever portion includes laterally projecting wings to fit with limited clearance relation in the side frame for maintaining key alignment.

12. A side frame key assembly as defined in claim 1 wherein one of the attachment portions depends from the retainer position and the other attachment portion depends from the lever portion and wherein said locking loop means is an extension spring reacting upwardly against said base portion to bias said keying structure downwardly against said horizontal base portion.

13. A side frame key assembly as defined in claim 11 wherein one of the attachment portions depends from the retainer portion and the other attachment portion depends from the lever portion and wherein said locking loop means is an extension spring reacting upwardly against said base portion to bias said keying structure downwardly against said horizontal base portion.

14. A side frame key assembly as defined in claim 7 wherein said retainer portion is of streamlined configuration and said extension spring reacts upwardly against said base portion to bias said keying structure downwardly against said horizontal base portion.

15. A side frame key assembly as defined in claim 12 wherein said extension spring is disposed within a wear sleeve of non-metallic material.

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