US1992412A - Releasing and holding means for railway car hand brakes - Google Patents

Description

Feb. 246, 1935. nR. w. BURNETT RELEASING AND HOLDING MEANS FOR RAILWAY GAR HAND BRAKES Original Filed May 28. 1928 brakes.

Patented Feb. 26, 1935 PATENT OFFICE RELEASING AND HOLDING MEANS FOR RAILWAY CAR HAND BRAKES Richard W. Burnett, chicago, VIll. Original application May 28, 1928, Serial No.

Divided and. this application Feb,-

ruary 27, 1930, Serial No. 431,763

7 Claims. (Cl. 18S-81.1)

This invention relates to railway car hand brakes and particularly to improvements in means for holding the hand brake mechanism in and releasing it from its brake setting position.

The primary object of the invention is to provide an improved releasingl and holding means for the hand power mechanism of a railway. car hand brake which will be relatively simple `in its operation although effective in its results, and which will permit the brakes to be wholly or partially released'under the control of the brakeman from a Vposition remote from the hand power mechanism. In thisA Yconnection the invention contemplates an operating lever for releasing the holding means which may be operated by the brakeman from a position on the ground or on the lower portion of the car but at the same time will permit the holding member to be re-engaged intermittently with the power mechanism to effect a notching oi or gradual release of the A'further object is to provide in a hand brake of the above character means which in combination with the releasing lever, may be positioned to lift the holding member out of -its holding position when the releasing leveris `actuated and whichalso may be employednot only to lift the holding member o-ut of its holding positionbut to apply a retarding pressure to a moving part of the power mechanism.

A further object is to provide a holding andreleasing mechanism which in addition to providing automatic means for supporting the-holding member out of its holding position provides `also an operating lever having a cam portion for engagement with the end of the holding member and adapted upon being swung to either side of the vertical axis of the operating lever to lift the holding member out of its holding position. y

This application is a division of my copending application Serial No. 281,088 led May 28, 1928 (Patent 1,939,953 dated December 19, 1933).

The invention is illustrated in one specific embodiment inthe accompanying drawing wherein: Fig. 1 is a front elevation of a railway car hand brake power mechanism with parts broken Y away and illustrating my improved holding and releasing mechanism in its normal position'for operation.

Fig. 2 is a similar View of the mechanism shown in Fig.. 1 but illustrating the parts ofthe power mechanism and theholding and releasing mechanism in different positions, and Fig. Sis a fragmentary plan View of the mechanism as shown in Fig. l illustrating the parts in the same relative positions as indicatedY in that gure. 3

The hand power mehanism illustrated'herein is `of a type in lwhich a chain or other suitable 5 connector is wound about a drum, the-latter being rotated by means of intermeshing gears operatively connected to a hand wheel. In the particular embodiment illustrated a chain-10 is attached at one end to an. arm 11 of a winding drum l2 and is attached at its other end to any suitable means for-transmitting .the power lto the brake rigging underneath the car. The Winding drum l2 is preferably provided with a grooved winding surface 13 of eccentric configuration and is so secured to a shaft 14v that the initial turning-.movement of the drum eiects aquick take-up of the slack in the connector 10 and 4various parts of the brake rigging and further movement winds the chain about a relatively small radius so as to apply maximum power after the brake shoes of the brake rigging have been moved into engagement with the wheels of the car. The diameter of the drum 12 is-preferably such'that the brake of any normal installation will be fully applied before the drum l2 has made one complete revolution. The shaft 14 is suitably journaled in the iront and back portions of a housing 15. The numeral 16 designates a large gear rigidly connected with the drum 12 so'as to lrotate therewith and meshes with the pinion 17 iixed yon a horizontal shaft 18 in the upper` portion of the housing. Theshaft 18 extends out of the iront portion of the housing and carries aA hand wheel.19 of suitable diameter for imparting the rotational movement to the winding drum.

It'will be seen that byrotating the hand wheelV 19 in a clockwise direction with reference to Fig. 1, rotation is imparted to the winding'drum 12 in the direction indicated by the arrow so as to wind the chain upon the drum in the manner Vindicated in Fig.` 2. In order to avoid reverse movement of the hand wheel `dur'mg the brake setting operation and toi also. provide for releasing the hand brake from its brake setting position, I have provided my improved holding and releasing mechanism. VThe specific construction of this mechanism illustrated herein consists preflerably of a ratchet wheel 20 secured to the shaft is formed also with an arcuate portion 24 which extends over the ratchet wheel and terminates in-a foot portion 25. A releasing lever 26 is pivoted at 2'7 to the housing and is formed with an enlargement 28 which provides a stop for the foot 25 of the pawl and serves also as a cam for raising the pawl 21 out of its holding position. The cam 28 preferablyvextends on both sides ofthe vertical center of the axis 27 so that movement of the rod 26 to either side of the vertical center will serve to raise the pawl l2l out of its holding position. The releasing lever 26 may be oi any suitable length, preferably it extends downwardly a distance sufficient to permit operation by a brakeman while the latter-` is'` standing on the ground. The fact that the releasing lever 26 may be operated 'bymoveinent -in either direction makes it possiblefor the brakeman, when standing on the car, to release the brakes by using his foot to operate the lever 26.

The pawl member 21 is formed also' with a tail portion 29. adapted to engage the ratchet wheel to limit the swinging movement of the pawl and also to provide means for exerting frictional retarding force on the ratchet wheel so` as to control the reverse spinning movement ofthe hand wheel and winding mechanism during'the brake releasing operation. In this connection Ithave provided a second releasing lever 30 pivoted preferably on the same axis as the pawl 21. The lever.30 is provided with a boss 31 adapted, when the lever is inthe position illustrated in Fig. 1 to bear upon the upper portion of the pawl 2l so as to maintain it in its ratchet engaging position and which when the lever 30 is moved to the position indicated in Fig. 2 will bear against a shoulder 31a of the pawl so that the lever 30 will serve as a counter weight tending to raise the pawl out of engagement with the ratchet when the braking pressure on the ratchet is released either by rotation of the hand wheel in a direction to set the brakes or b'y manipulation of the releasing Vlever 26. When the lever 30 is in the position indicated in Fig. 2, the reverse spinning movement 'of the winding mechanism may be retarded by exerting pressure downwardly on the lever thereby forcing the tail-piece 29 of the pawl into frictional .engagement with the ratchet wheel.r The Ylever 30 mayalso be used to release the pawl independently of the operation of the lever 276.

Operation of the holdng'and'releasing mechansmrY-Assuming that the brakes are fully set vwith the holding pawl in a position to prevent reverse movement of the windingV drum the pawl may be lifted out of its holding position by movement of the releasing lever 26 to either side of its vertical axis. If it is desired to eliect a step by step release the holding 'pawl 21 may be` permitted to reengage with the ratchetv gear 20 by a return movement of the lever. 26 to its normalvertical position whereupon the weight oi the pawl together with the additional weight of the lever 30 will cause the pawl to reengage the ratchet. If it is desired to effect an instantaneous release the lever 30 may be moved to the yposition indicated Vin Fig. 2 whereupon a single, operating movement. of the lever 26 will disengage the pawl and ratchet so that the weight of the lever 30 will support the pawl out oi engagement with the ratchet; The same resultA can be obtained, for example when a graduated release is vdesired throughmanipulation of rthe vhand wheel, byrrotating the hand wheel in ,a

direction'to, release the Abraking pressure, from the tooth 230i the pawl whereupon the weight of the lever 30 will rlift the pawl and support i in the position indicated in Fig. 2. The release of the brakes may then be controlled by the manipulation of the hand wheel 19 or if desired by the downward pressure on the lever 3c so as to iorce the tail portion 29 of the pawl into frictional engagement with the ratchet. The lever 30 may be used indpendently or theV lever 26for lifting the pawl 21 out of its holding position when the braking pressure on the pawl is such not to require compound leverage to effect said release.

While I have illustrated my invention in connectionvwith one specific embodiment, it will be obvious to persons familiar with this art that various modifications may be made in structure without departure trom the spirit of the invention. It will therefore be understood that my invention contemplates all such modications coming within the scope of the appended claims.

I do not claim'herein the holding and releasing arranged hand wheel said combination is claimed in my said copending application Serial No. 281,688, (Patent 1,939,953, dated December mechanism in combination with the vertically formed at one `end with an extension terminating in' a foot and at the other end with a tail-'piece adapted to be moved into engagement with the -ratchet when the pawl is moved to its ratchet releasing position, anV operating lever pivoted near its upperY end and formed .with a cam operable by a brakeman standing on the ground, to lift the pawl out-of its holding position, a holding andtripping device pivoted on the same axis as the pawl adapted inone position tobea'i against the pawl to ,maintain it'in its holding position and` in another position to bear against thetail portion of. the pawl to support Vthe pawl in its released position. Y 2. Holding and releasingmechanism for railwaygcar hand brakes comprising a `ratchet wheel, a pawl pivoted yto engage the ratchet wheel to hold it against movement in one direction formed at one end with an extension terminating in a foot-piece and formed at the other end with a Vtail adaptedftov be movedinto engagement with said ratchet when the pawl is moved to its ratchet releasing position, a normally vertically `disposed operating-rodvformed witha c am portion'for engagement with said foot-piece ofthe pawl and Vadapted upon swinging movement ofthe lever to p upon the upper portion of thepawl to maintain it in engagement with the ratchet and in another position to supportthe pawl out of Aits holding position during the releasing operation ofv the handpbrake.V ,Y n

3. Holding Y and releasing mechanism` forA railway lcar hand brakes comprising a ratchet wheel rotatable about a horizontal axis, a pawl pivoted to engage said ratchet to hold it against reverse movement and formed at one end with la tailpiece and means for releasing the hand brake under control of the operator comprising alever pivoted on the same axis, as the -pawl for lifting the pawl out of its vholding position and adapted upon continuous movement thereof to force the said tail portion of the pawl into frictional engagement with said ratchet.

V4. Holding and releasing mechanism for a rail- Way car brake comprising a ratchet, a pawl for holding the ratchet against reverse movement when the brakes are in set position, a lever for forcing the pawl from engagement with the ratchet against braking pressure between said elements, and a lever which in one position tends to establish and maintain engagement between the pawl and ratchet and in another position to lift and hold the pawl out of its ratchet holding position when the said braking pressure between the pawl and ratchet is relieved.

5. Holding and releasing means for a railway car brake comprising a ratchet, a pawl for holding the ratchet against reverse movement when the brakes are in set position, a lever provided with a cam to bear against said pawl for disengaging the same from the ratchet, and a member which in one position tends to establish and maintain engagement between the pawl and ratchet and in another position to automatically lift and hold the pawl in a position free of the ratchet upon release of the braking pressure on said pawl.

6. Holding and releasing mechanism for a railway car brake comprising a ratchet, a pivoted pawl for holding the ratchet against reverse movement when the brakes are in set position, a lever pivoted on a diierent axis from the pawl engageable therewith to disengage the ratchet from the pawl, and a member which in one position tends to establish and maintain engagement between the pawl'and ratchet and in another position to lift and hold the pawl out of its ratchet holding position when the braking pressure between the pawl and ratchet is relieved.

7. Holding and releasing mechanism for a railway car brake comprising a ratchet, a pawl for holding the ratchet against reverse movement when the brakes are in set position, an operating rod pivoted to hang in a vertical position and provided with a cam adapted to bear against the pawl and to disengage it from the ratchet when the rod is turned to an oblique position, anda member which in one position tends to establish and maintain engagement between the pawl and ratchet and in another position to lift and hold the pawl to a position free of theratchet when the braking pressure between the pawl and ratchet is relieved. A i

RICHARD W. BURNETI.

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