US1639669A - Brake device for railway cars - Google Patents

Description

231927. Aug F. c. RUTZ BRAKE DEVICE FOR RAILWAY CARS Filed May 5. 1926 a chain and drum, in that the desired in- Patented Au 23, 1927.

ne ates FRANK C. RUTZ OF ROGKFORDyILLiINOIS: v

BRAKE nnvxon ron RAILWA cans;

Applicationfiled. may 5, 1926 SerialNo, 106,790.

This invention relates to brake devices'for railway cars and is an improvement on'the invention described in my U. S. LettersjPatent N0. 1,62%,510, granted April 12, 1927. In said patent i have explained some 01fthe reasons why it is desired to improve'the present so-called standard hand wheel or leverbrake with the view to increasing or boosting the braking force so that it will be at least equal to, it not greater than,,that applied by the air brake mechanism. I That invention is characterized by the provision of a mast drum mounted for rotationin a casing andhaving a spiral groove Ofapproximately uniform pitch and diameter in which a cable or other suitable flexible means connecte'd with the brake rigging isjadapted to be wound for exerting the braking pull, and in the furtherprovision that the mast drum is so shaped as to enable the center line of the pull'to be brought close to its center to secure a shorted lever arm and consequently, a greater mechanical advantage. As a result a smooth, cOnstantand increased eliective braking force isobtaine'd by the application, 01": the normal hand braking iorce. Said invention further provides against fouling of the cable or flexible means on the mast drum when winding 0r unwinding.

The primary: object of the present invention is to attain a similar result under the same or similar conditions with the use of drum in elev the standard link'chain now employedwith brake devices in general, in place of the cable shown in my prior application. By the use of a chain of this kindthe conven tions of railway V practice' are adhered to and, at the same time, a new result is accomplished "in hand brakes with the use of crease in effective brakingforce is obtained to meet the railway requirements thatfthe braking force against the wheels fbee ual approximately to of the light weight of the car. This result is obtained in the present invention by thefprovision or mast drum having a spiralthreadfor refceiving the standard chain, thepitch or the thread being preferably uniform from end to end of "the drum and the thread and groove being so shaped as to insure a con- "stant lever arm with the alternate links approximately meeting the longitudinal axis t1" the drum. "While the'pres'ent invention brake 'ri is predieated primarily on this type of mast the bral ze Other objects and V Fig. 3, isa horizon stantially on the line 3'3ot Fig. 2';

Fig. 4,,is a further enlarged fragmentary section taken substantially on the line designated by l, Fig 3, this section extending only to the longitudinal center referred to hereinafter; and p I r v ilar fragmentary section showing a modified form of groove or chain score in the mast drum;

WVhile my inventionis primarily'ihtend ed for application in a hand brake device it should he hnclerstoocl that in its broader sense itis'applicable to any railway brake whether operate'dfby hand .or'hother'wise. The present"illustrationis. therefor-e, merely "apreferred embodiment aridisito some degree diagrammatic, especially in respect to the co nnection'between thebrake chain and Fig. 5 is; a 'sim gging'. Thej drawing shows on 'tional frei-ght'box car the body of which 'is "designatedgenerally by 5. Only such parts of the brake mechanismareshown as are necessary for an understanding of the present invention. The'well known parts com- 105 rise a bralze'shaft or mastfi, anupper bearbracket 7,a'whee'l'8 fixed to the top'end time 'sha ft, arat'chet wheel Q'fiXed to the shaft andliavi-irgthe usual pawl for prevent ing the wheel and shaft from turning back= "ward, and a brake rod 11connecte'd'through struction which "ma duced.

ation gii'ig-a ndf the cylinc tal 'sectiontaken subdrum for aibrake chain, I prefer that it shall be employed substantially in the combination disclosed in finy prior application 111 whlchthelmast drum is mounted for rotation -in ah'ousing' vor casing adapted to be 1n turn mounted on the railway car in place of, the usualistrap which provides support for the lower end of the brake shaft. This gives a sun'ple and thoroughly practical con y be economically pro- I attendant advantages will be appreciated by" those skilled in this art as the invention becomes better understood by reference to'thefollowing' descriptron when considered in connection with the accompanying drawings, in w'hich- Figure 1, is a fragmentary'side elevation of one end of a railway car equipped with a hand brake .deviceenibodying my invention; 2, is an enlarged vertical section through the brake device showing the mast 6 end ofa conven-- push rod 1 and the brake shoes in a suitable or preferred manner well known in this art.

In applying my invention to a railway car having the usual hand brake, I remove the brake shaft 6, cut off the cylindrical drum at the lower end thereof, square the end 12 of the shaft and substitute for the cut 013? end a mast drum designated generally by 13 which has a squared socket 14 for the reception of the squared end 13 of the brake shaft. The mast drum and brake shaft may be se cured'together by any suitablesmeans such, forexample, as a bolt 15 passing through the interfitting parts.

The mast drum .is supported for rotation in a casing or housing designated generally by 16 which in turn is shaped for rigid attachment to the railway car. This casing replaces the usual mast step which gives support to the lower end of the usual brake shaft. The casing may have a broad flat portion 17 adapted to be clamped against the car structure or body by bolts 18, and a horizontal rib 19 adapted to seat against the i underside of the car body for locating the casing and for resisting any tendencies to tilt the same. The casing is further shaped to provide a cylindrical portion 21 depending from the attaching portion and being open at its top for reception of the mast drum and having a bottom wall 22 providing a bearing 23 for the reduced lower end 24 of the mast drum. The mast drum is held from upward f displacement by suitable means such as a cotter pin 25 passing through its projecting lower end 2 1. The casing further provides lateral bearing support for the upper end of the mast drum, this purpose being served by a semi-circular bearing surface 26 for the cylindrical portion 27 of the drum which is located intermediate the square socket end or shank and the spirally grooved portion of the mast drum. It will be observed that the cylindrical portion 27 also serves to substantially close the opening at the upper end of the cylindrical portion 21 of the casing.

The mast drum is spirally grooved sub stantially from end to end in a novel manner to provide for the winding of a standard brake chain with the chain approximately meeting on successive convolutions the longltudinal center or axis. The mast drum is furtherdesigned to insureproper and positive winding of the chain in the spiral groove and to prevent slippage and displacelIlQIlliOf the links from such determined an groove upon said drum. rangement on the drum. The mast drum 1s also designed so as to provide a cross-section adequate to take care of the heavy strains and stresses incidental-to the varying conditions of usage. I

As shown in Fig. 4 the cross-section of the spiral teeth issubstantially T-shape, identified by the parts 28 and 29, the latter of which provide continuous shoulders on which the alternate links 31 (lisposed parallel with the axis 32 are adapted to ride and the intermediate leg part 28 providing a.

continuous outstanding tooth which defines the pitch and space into which the chain is adapted to enter and leave the drum. The

space or groove between the spiral teeth is continued inwardly between adjoining shoulder parts 29 to provide a groove or score 33 reaching approximately to the axis 32. This portion of the spiral groove or chain score is for receiving the alternate links 34- intermediate the links 31 and is disposed at substantially right angles thereto in a plane transverse to the said axis. 1 The total depth of the chain score or groove is,

therefore, equal to, and preferably slightly greater than, the outside width or dimension d formed by the casing serves, therefore, to

guide the chain in its passage to and from the mast drum and to prevent displacement of the chain therefrom.

One end 37 of the chain is suitably fas tened to the mast drum as, for example, by means of abolt 38 passing through this ter minal link and threaded into the drum proper. This end of the mast drum is recessed at 39 for the reception of the link V 37 and a bolt hole is drilled from the upper end of the drum through the body at both.

sides of, the recess 39 so as to provide for rigid and substantial attachment of the bolt to the drum. The opposite end of the chain .after having been passed through a pulley 41 011 the brake rod 11 isattached at 42 to the center body sill'or to any suitable point on the car. The connection between the be varied according to the conditions at hand or to meet any particular require ments; consequently, the present construction is merely for purpose of illustration.

. chain, brake rigging and car may, however,

In practice, to tighten the br'akes the brake shaft will be turned so as to rotate the mast drum in a clock-wise direction. viewing Fig. 3, thus winding the chain in the s iral Because '0 the shape of the mast drum the chain will properly follow the spiral groove,each alternate link 34 riding in the deepest portion or score 33 of the groove and each alternate link 31 riding on the shoulders. 29 between the outstanding tooth parts 28. By reason of the lfactkthat' the chain is brought to the axis l the effeetivelever'arm'is shorter than-,has

heretofore been attained as a constant with the use of a standard chain wound on a mast drum. In other words, throughout the successive convolutions of the. chain-receiving groove the chain approximately meets and, in fact, it does meet in practice, as shown on Figs. 4c and 5 of the present drawings, the axis of the drum. As a result the effective lever arm is constant at all times regardless of the particular position or stage of the winding. This is particularly desirable in that it enables the maximum braking force to be applied irrespective of variations in the length of the chain or in the particular point on the drum atwhich the brakes are brought home withthe maximum pull. The fact that this point is a variable is taken care of excellently with the present construction. It should also be noted that since the greatest lateral stress on the drum occurs at a time when the chain is approximately midway between its ends there is apt to be a slight lateral deflection of the drum toward the side of the pull. To prevent injurious deflection and to resist this side thrust the wall 43 of the casing is carried close to the periphery of the drum and acts as a thrust bearing or wall. The tendency to spring this wall is resisted by a series of circumferential reenforcing ribs 44:.

In Fig. 5, I have shown a modified form of mast drum in which the spiral groove or chain score 45 does not have the shoulders 29 above-mentioned, but instead the bottom of the groove is shaped to receive the links of the chain in any angular rela geous in that it lends itself better to castone piece.

lVith the use of my improvements a comparatively smooth steady braking pull may be applied with a constant leverage, the effective leverage being such that the average hand force applied on the hand wheel -or lever is capable of applying a braking character described, without departing from it the spirit and scope of the invention as expressed in the appended claim, in which- I claim:

A hand operated brake device of the character described, comprising a rotatable mast r drum having a spiral groove, a brake chain wound in said groove on the mast drum, the

bottomof the groove from end to end being approximately coincident with the axis of the drum, the drum having a bearing mem- T ber at each end, and a casing enclosing the spiral portion of the drum and providing abearing for 'each bearing member thereof and having an elongated chain opening be tween said bearings through which the chain emanates.

In witness of the foregoing I aflix my signature.

FRANK C. RUTZ.

ing the mast drum to the desired shape in

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