US2017526A - Holding and release tripping mechanism for railway car hand brakes - Google Patents

Description

Oct 15, 1935. R w BURNETT 2,017,526

HOLDING AND RELEASE TRI IPPING MECHANISM FOR RAILWAY CAR HAND BRAKES Filed Aug. 5, 1929 4 Sheets-Sheet 1 Oct. 15, 1935. R. w. BURNETT 2,017,526

HOLDING AND RELEASE TRIPPING MECHANISM FOR RAILWAY CAR HAND BRAKES Filed Aug. 5, 1929 4 Sheets-Sheet 2 IIIIIl/IIIIII III 0d. 15, 1935. R w BURNETT 2,017,526

HOLDING AND RELEASE TRIPPING MECHANISM FOR RAILWAY CAR HAND BRAKES Filed Aug; 5, 1929 4 Sheets-Sheet 3 Oct. .15, 1935. R. w. BURNETT 2,017,526

HOLDING AND RELEASE TRIPPING' MECHANISM FOR RAILWAY CAR HAND BRAKES Filed Aug. 5, 1929 4 Sheets-Sheet 4 Patented Oct. 15, 1935 UNITED STATES PATENT OFFICE HOLDING AND RELEASE TRIPPING BIECHA- NISM FOR RAILWAY CAR HAND BRAKES 12 Claims.

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

A principal object of the invention is to provide improved holding and releasing means which will be durable in construction and efficient in operation, whereby the brakes may be readily and conveniently released either instantaneously by one movement of the releasing lever, or by a step by step release involving successive engagements of the holding member with the power mechanism.

The invention also contemplates a holding and releasing mechanism in which the holding mechanism is normally in engagement to resist reverse movement of the hand power mechanism but which is so arranged as to permit simultaneous operation of the releasing lever and hand wheel, whereby a graduated release of the brake may be had by manipulating the hand wheel while supporting the holding member out of engagement with the power mechanism.

A further object is to provide improved holding and releasing means in which the movement of the releasing lever in one direction will disengage the holding member, and move into frictional engagement with the power mechanism a retarding element adapted to retard the reverse movement of the hand power mechanism, thereby permitting, in addition to the instantaneous and step by step release, a graduated or retarded release without requiring the brakeman to grasp the hand wheel.

Further objects of the invention willappear from the detailed description of the embodiments of the invention shown in the accompanying drawings.

This application is a continuation in part of my copending application Serial No. 160,870, filed January 13, 1927. The present application, however, is not especially concerned with the combination of a particularly shaped winding drum and bell crank for transmitting the power to the brake rigging beneath the car, but relates particularly to improvements in the means for holding the hand power mechanism in brake setting position and for releasing the mechanism from that position.

In the drawings:

Fig. 1 is a front view partly in elevation and partly in section of a hand brake, together with the holding and releasing mechanism, constructed in accordance with my invention.

Fig. 2 is a. sectional view taken on line 2-2 of Fig. l.

Fig. 3 is a side view in elevation of the com struction shown in Fig. 1 looking towards the right hand edge of the said Fig. 1 and illustrat- 5 ing the manner in which the releasing lever is extended around the side of the housing.

Fig. 4 illustrates a hand power mechanism, together with the holding and releasing mechanism of the same general character as that illustrated 10 in Fig. 1, but illustrating the manner in which the releasing lever may be reversed in position whereby the weight of the lever will move the holding pawl into engagement with the hand power mechanism to prevent reverse movement 15 of said mechanism.

Fig. 5 is a, fragmentary view illustrating an arrangement andconstruction of holding pawl and releasing lever by which the releasing lever engages an end portion of the pawl remote from 20 the tooth end thereof.

Fig. 6 is a fragmentary view illustrating another modification in which the releasing lever bears against a projection extending beyond the holding edge of the pawl.

Fig. '7 is a front view of the holding and releasing mechanism modified so as to provide the holding pawl with a jaw portion for embracing and engaging a portion of the releasing mechamsm.

Fig. 8 is a view similar to Fig. 7 showing the holding member disengaged from the ratchet teeth and showing also a retarding member moved into engagement with said teeth.

Fig. 9 is a view in perspective illustrating the 35 oflz'set position of the jaws of the pawl shown in Fi 8. i

Fig. 10 is a further modification showing the jaws of the holding pawl disposed in a single vertical plane, and

Fig. 11 is a view in perspective of the pawl shown in Fig. 10.

Referring first to Figs. 1, 2, and 3 of the drawings, wherein I have illustrated one embodiment of my invention in connection with a hand power mechanism adapted to be attached to the inner face of a railway car end wall. The power mechanism as shown in these figures consists principally of winding mechanism comprising a. winding drum l0 revoluble with a large gear ll about an axle II. The winding drum and gear H are journaled in the lower portion of a two part housing l3, consisting of a, front portion and a back portion l3 and M, respectively. The winding surface of the drum in is preferably in the form of a groove l5 of eccentric configuration, about which a flexible connector, preferably a chain I6, is adapted to be wound. One end of the chain is permanently attached to the winding drum at H scribed in detail in the present application. Rotational movement of the drum l0 and gear II is provided through a vertically disposed hand wheel I8 fixed to a shaft IS. The shaft I3 is provided preferably with a small pinion 20 and a ratchet wheel 2|. The shaft I9 is journaled in suitable bearings 22 in the housing l3 so that the pinion 20 will mesh with the large gear II. It will be seen that rotation of the hand wheel IS in clock-wise direction with reference to Fig. I will impart a turning action to the drum Ill and large gear II in the direction indicated by the arrow in Fig. 1, whereby the chain I6 will wind first upon the surface 23 of a small diameter and then upon a surface 24 of a larger diameter.

The winding mechanism is releasably held against reverse movement by'a ratchet mechanism consisting of the ratchet wheel 2| and a pawl or dog 25. The pawl is pivoted at 26 in a position so that the tooth end 21 thereof will.

drop into engagement with the teeth of the ratchet wheel. The pawl is formed at one side with a web 2! adapted to be engaged by a rocking jaw member 28, the latter of which is secured to a horizontally disposed rocking shaft 23. The shaft 29 is preferably positioned near the end of the pawl 25. An operating lever 30 is secured to the shaft 29 so as to rock the jaw member 28 into a position to press upon the pawl 25 and thereby hold it in a position to ratchet over the teeth of the ratchet wheel. Downward movement of the lever 30 rocks the jaw member in a manner to lift the pawl 25 out of its locking engagement with the ratchet wheel. The jaw member 28 is formed with a long jaw 3| and a short jaw 32 which together embrace the web 2! of the pawl. The long jaw 3| bears against the upper surface of the web 21 at a point near the pivot axis of the pawl. With this arrangement, the movement of the pawl, as it rides over the ratchet teeth will not produce any appreciable movement of the outer end of the lever 30. The short jaw 32 engages the under surface of the web 21 at the end of the web and relatively close to the pivotal axis of the jaw member, so as to provide maximum pressure against the: under surface of the web when it is desired to release the pawl. The operating lever 30 is preferably connected through a rod 33 to a foot lever 34. The upper end of the rod is provided with a removable clevis 35 so that the rod may extend through a coil spring 36, in position between the outer end of the lever 30 and a guiding bracket 31 adapted to be secured to the end wall 38 of the car. The spring 36 holds the lever 30 and the jaw member 28 in the position as shown in Fig. 1 so that the long jaw 3| is pressed with spring pressure against the upper surface of the web 21 of the pawl, thereby holding the pawl in engagement with the ratchet teeth. In order to provide suitable clearance between the end of the operating lever 30 and the periphery of the hand wheel l8, the end of the lever 30 is formed to project around the edge of the housing as shown in Fig. 3.

In some installations it is desirable that hand operating means, for example, hand wheel l8,

be provided on the inner and the outer walls of the car, so that the brake mechanism may be extended through the wall 38 of the car as in- 5 dicated at IS in Fig. 3 so that a hand wheel can be affixed thereto. In this connection the invention contemplates also the provision of a tripping lever on the outside of the car. This tripping lever is provided by afiixing to the end 10 29 of the shaft 23 a hand lever 30 shown in dotted lines in Fig. 1. The spring 35 will serve to support the weight of both operating levers in the position indicated in Fig. 1. In situations where it is desirable to provide means for foot 15 operation of the outside tripping lever 30*, a foot lever of the type shown in Fig. 1 may be applied to the outside of the car and connected to lever 30'.

Operation In applying the brakes, the hand wheel is rotated in a clock-wise direction with reference 'to Fig. I, thereby imparting a rotation of the winding drum in the direction indicated by the arrow so as to wind the chain I 6 upon the drum, first upon the surface 23 and .then upon the surface 24. During this movement of the winding mechanism the pawl 25 ratchets over the teeth of the ratchet wheel; the spring 36 exerting pressure upwardly against the lever 30 30 insures engagement of the pawl 25 with each of the ratchet teeth during the brake setting movement of the hand power mechanism. The brake setting operation can be accomplished with one hand of the operator while he holds onto the 5 car with the other hand. If it is desired to release the brake entirely and quickly, the lever 30 is pressed downwardly, either by hand or by means of the foot lever 34, so as to raise the tooth 32 of the pawl out of engagement with the 40 ratchet teeth, whereupon the pressure of the brakes against the car wheels together with the weight of the connector It produces a reverse spinning of the hand wheel and gear mechanism. This reverse movement can be interrupted 45 at any time by movement of the lever 30, either by hand or by the reflex action of the spring 36, into a position to move the pawl 25 into engagement with the teeth. This operation is ordinarily effected when it is desired to release the 50 brakes by a step by step operation-by successive movements of a lever 30 to disengage and permit reengagement of a pawl 25 with the ratchet teeth. When it is desired to effect a graduated release of the brakes, (a method employed 5 when a relatively small braking pressure is required and during which the operator manipulates the hand wheel to either increase or diminish the braking pressure as may be desired), the outer end of lever 30 is pulled downwardly and held in that position. This movement of the outer end of the lever causes the jaw end 28 to rock upwardly to disengage the pawl 25 from the ratchet teeth and support the pawl clear of the ratchet.

In Figs. 1, 2, and 3, I have illustrated a con: struction in which the lever 30 is so positioned that a spring or other force is necessary to hold the lever 30 and pawl 25 in normal operative position. If it is desirable to dispense with the use of the spring 36, the lever 30 may readily be positioned on the shaft 29 in the position indicated in Fig. 4, whereby the weight of the lever will be suflicient to hold the long Jaw 3| down 15 .tooth end of the pawl.

upon the pawl 25 and insure engagement of the tooth end of the pawl with the ratchet teeth during the brake setting operation of the power mechanism. With this embodiment the lever 30'' is raised to force the small jaw 32 into engagement with the under surface of the pawl and is rocked downwardly to move the long jaw into engagement with the upper portion of the pawl. In other respects the mechanism in Fig. 4 is identical with the mechanism shown in Figs. 1 to 3, inclusive.

In Fig. 5 I have shown a modified construction in which the jaw member 2|! is pivoted in a position above the pawl 45, the latter of which is formed with a tail 4| adapted to project between the jaws 3|, 32 of the jaw member. The tail 4| may be made of any suitable length, whereby the leverage action may be compounded to any extent desired. The operation of the trip lever 30 may be by means of a spring mechanism 35 as shown in Fig. 1, or the position of the lever 30 may be reversed from that illustrated in Fig. 5 to the position shown in Fig. 4 so that the weight of the lever will hold the long jaw in engagementwith the pawl 40.

In Fig. 6 I have illustrated another modification in which the end portion of the pawl 42 is provided with a forward projection 43 at the The jaw member 44 is provided with a small jaw 45 for engagement with the under portion of the projection 43 and is formed with a long jaw 45 for engagement with the upper portion of the pawl 42 near its pivotal axis. With this arrangement, the jaw member may be positioned above the ratchet wheel without interfering with its operation. This modification is illustrated in connection with the use of the foot lever and spring 35 but is readily susceptible to change in accordance with that illustrated in Fig. 4 by merely reversing the position of the trip lever, so that the weight of the lever will hold the long jaw of the jaw member down upon the upper portion of the pawl.

It will be observed that I have illustrated in each of the preceding embodiments a' rocking jaw member adapted to embrace a portion of the holding pawl. This condition may be readily changed so as to provide the pawl with the jaw for embracing a portion of the tripping lever. A modification of this character is illustrated in Figs. 7, 8, and 9 wherein 41 designates the ratchet wheel of the holding and releasing mechanism, 48 the holding pawl, 49 a cam member for bearing against the pawl. and 50 a tripping lever for moving the cam member to difierent angular positions. The holding pawl 48 is formed with upper and lower jaws 5|, 52 which together embrace a part of the cam member. When the tripping arm 50 is in the position indicated in Fig. '7 a long finger or cam member 53 bears down on the upper surface of the short jaw 52, so as to hold the tooth end 54 of the holding pawl in engagement with the teeth of the ratchet wheel. It will be observed that the member 53 bears against the small jaw 52 at a point near the pivotal axis of the pawl. Consequently the ratcheting movement of the pawl over the teeth of the ratchet wheel will not produce major oscillating movements of the tripping lever. In order to permit the tripping lever to swing through a relatively large arc, the short jaw 52 is offset laterally with relation to the long jaw 5| so that when the tripping lever is moved to a position to lift the holding pawl out of engagement with the ratchet. the long finger 53 will clear the side face of the long jaw 5| as illustrated in Fig. 8. During this movement of the tripping lever the short finger 55 of the cam member is brought into engagement with the bottom surface of the long jaw 5| near its end, so as to effect a compound leverage. on the pawl 48 to lift it out of engagement with the teeth of the ratchet. The pawl 48 is preferably formed with a tail portion 56 adapted, when the pawl is lifted out of engagement with the teeth, to bear frictionally against the teeth of the ratchet wheel so as to retard and control the reverse movement of the power mechanism. The tail portion 55, it will be seen, is brought into engagement with the ratchet wheel by the continued swinging movement of the trip lever immediately after the tooth 54 of the pawl is disengaged from the ratchet. Hence, the movement of the trip lever in one direction releases the pawl from its holding po- 20 sition and moves another element, the tail 55, into frictional engagement with a moving part, the ratchet wheel, of the power mechanism. Preferably, the short cam member 55 is so positioned that it is necessary to move the trip lever 5|! -beyond the vertical center to efiect disengagement of the tooth 54 from the ratchet teeth. With this arrangement the weight of the lever 50 provides a counter-balance for the pawl member to hold it out of engagement with the ratchet teeth, whereby a graduated release of the brakes, by manual manipulation of the hand wheel to increase or release the braking pressure, may be had without requiring the operator to support the holding pawl out of engagement with the teeth of 35 the ratchet. application of pressure on the lever, when it is in the position indicated in Fig.

8, further tilts the pawl 48 in a direction to force the tail 55 of the pawl into frictional engagement with the ratchet with sufilcient pressure to retard 40 the reverse movement of the power mechanism.

In Figs. 10 and 11 I have illustrated an embodiment similar to that shown in Figs. '1, 8, and 9, but so modified, that the side face of the jaws 5|, 52, are in the same vertical plane. In this modification, the cam member 49, during its rocking movement, is confined within the space between the jaws 5|**-52 of the pawl 48. Preferably the distance between the lower surface of jaw 5| and the upper surface of jaw 52 is such 50 that, when the pawl is raised out of engagement with the ratchet and the retarding tail 56 is pressed against said ratchet, the end 53 of the cam 49 will not contact with the upper jaw 5|. The end of the long jaw 5|, like that of the cor- 55 responding jaw of Fig. 7, is formed with a curved surface for bearing upon the surface 49 of the tripping cam 49. The tripping lever 50" is so positioned that its we ght serves to hold the end 53 of the cam down against the jaw 52 and con- 60 sequently maintains the pawl in engagement with the ratchet.

The operation of this modified construction is the same as that of Figs. 7 and 8, except that the lever 5|! cannot be moved into a position in which its own weight will hold the tooth end of the pawl disengaged from the ratchet.

-'While I have illustrated my invention in connection with several specific embodiments, it will 70 be understood that I do not wish to limit myself to the specific structures shown and described except insofar as the state of the prior art may require, or the claims contain expressed limitation.

I claim: l

l. Ina railway car and brake, the combination with hand power mechanism operable in one direction to-set the brake, of means for holding said mechanism in and releasing it from its brake setting position, comprising a pivoted holding member and areleasing member, one of which is formed with a portion embracing a part of the other and engaging therewith at spaced locations on the same side of the pivotal axis thereof but at different distances from said pivotal axis, whereby movement of the releasing member in one direction exerts multiplied leverage on the holding member and when moved in another direction exerts pressure on the holding member to hold it movably in its normal brake holding position.

2. In a railway car hand brake, the combination with hand power mechanism operable in one direction to set the brake, of means for holding said mechanism in and releasing it from its brake setting position comprising a pawl pivoted for engagement-with a moving part of the power mechanism and a releasing member pivoted on a dififerent axis from the pawl and including a pair of jaws for embracing a portion of the pawl and adapted when moved in one direction to engage the end portion of the pawl at a location remote from its pivotal axis to lift it out of holding position and when moved into another position exerts pressure on the pawl nearer its pivotal axis to retain it movably in its holding position.

3. In a railway car hand brake the combination with hand power mechanism operable in one direction to set the brake, of means for holding said mechanism in and releasing it from its brake setting position comprising a pawl pivoted for engagement with a moving part of the power mechanism and a pivoted releasing member pivoted on an axis separate from the pawl and including a rocking member formed with a long jaw and a short jaw which together embrace a portion of the holding member; said long jaw being adapted to bear against a portion of the pawl to retain it movably in its holding position and the short jaw being adapted to exert pressure on the pawl to lift it out of its holding position.

4. In a railway car hand brake, the combination with hand power mechanism operable in one direction to set the brake, of means for holding said mechanism in and releasing it from its brake setting position comprising a pawl pivoted for engagement with a moving part of the power -mechanism and a pivoted releasing member in cluding a rocking member recessed to provide a pair of jaws for embracing a portion of the pawl and a lever for operating said rocking member, the said rocking member being adapted when rocked in one direction to exert pressure against an end portion of said pawl to lift the pawl out of holding position and when rocked in another position to exert pressure nearer the pivotal axis of the pawl to hold it movably in its normal holding position, and a spring member for holding said rocking member in its last mentioned posi-'- tion.

5. In combination with the brake rigging of a railway car, manually operable means for setting the brake and means for holding said mechanism in and releasing it from its brake setting position comprising a ratchet member operable with said brake setting mechanism, a pawl pivoted to engage said ratchet to hold said mechanism in the brake setting position, and means for releasing the pawl from its engagement with said ratchet, comprising a rocking member on an axis separate from the pawl and formed with jaws embracing a part 01' said pawl and adapted to engage therewith at difierent distances from a a railway car, a manually operable mechanism 15 for setting the brakes comprising a winding drum provided with a large-gear; means connecting the brake rigging with the winding drum and adapted to be wound thereon to set the brakes,

a small gearmeshing with the large gear, means 20 for rotating said small gear, a ratchet wheel on said gear, a pawl engaging the ratchet and formed at one side with a flange, a pivoted jaw member disposed near the tooth end of said pawl, and provided with along jaw and a shorter jaw which 25 embraces the flange of said pawl, a lever operatively connected with said jaw member to oscillate the same; the jaw member being so arranged with relation to the pawl that the short jaw thereof bears against the flange at a point near 30 the end of the pawl and the long jaw bears against the flange at a point near the pivotal axis of the pawl, and a spring positioned to press against the lever to force said jaw member in a direction to force the said long jaw against the pawl.

7. In a railway car hand brake, the combination with hand power mechanism operable in one direction to set the brake, of means for holding said mechanism in and releasing itfrom its brake-setting position comprising a pivoted hold- 0 ing member and a releasing member pivoted on an axis different from the holding member and provided with an arm engaging the holding member, the said holding member being provided with spaced jaws which embrace said arm and engage 5 opposite sides thereof at different distances from the pivotal axis of the releasing member; the engagement of the holding and releasing members at the greater distance from the pivotal axis of the releasing member being adapted to retain 50 the holding member movably in its holding position.

8. In a railway car hand brake, the combination with hand power mechanism operable in one direction to set the brake, of means for hold- 55 ing the power mechanism in and releasing it from its brake-setting position comprising a holding member and a releasing member, one of which is provided with a portion embracing a part of the other, whereby movement of the releasing 0 member in one direction moves the holding member out of holding position, and means on the holding member movable by the continued movement of the releasing member into frictional engagement with a moving part of the power mech- 5 anism to retard the reverse movement thereof.

9. In a railway car hand brake, the combination with hand power mechanism operable in one direction to set the brake, of means for holding said mechanism in and releasing it from its 7 brake-setting position comprising a pawl pivoted for engagement with a moving part of the power mechanism, and a rocking member including a cam arm pivoted on a separate axis from the pawl and engaging the pawl at locations spaced 7 longitudinally of the arm for holding said pawl in and releasing it from its holding pomtion, said pawl being provided with spaced jaws between which said cam arm is confined during its rocking movements.

10. In a railway car hand brake, the combination with hand power mechanism operable in one direction to set the brake, of means for holding said mechanism in and releasing it from its brake-setting position comprising a pawl formed at one end with a retarding tail adapted to be moved into frictional engagement with the power mechanism and at the other end with a tooth for engagement with a moving part of the power mechanism, and a cam member pivoted on a separate axis from the pawl and adapted to engage the same to hold it in and release it from'its holding position, said pawl being formed with spaced jaws between which said cam is confined during its movements from one position to another.

11. In a railway car hand brake, the combination with hand power mechanism operable in one direction to set the brake; of means for holding said mechanism in and releasing it from its brake-setting position comprising a pawl formed at one end with a tooth for engagement with a moving part of the power mechanism and formed at the other end with a tail portion and a member pivoted on a different axis from the pawl and provided with spaced jaws embracing said tail portion and having surfaces for engaging opposite sides of the portion embraced at different locations from said pivotal axis. of the pawl,

wherebymovement of the jaw member in one direction moves one of its laws into engagement with the tail of the pawl at a location remote from the pivotal axis of the pawl to force said pawl setting position comprising a-pivotally supported 15 holding member anda releasing member pivotally supported on an axis different from the axis of the holding member; one of said members being provided with a portion embracing a part of the other and having a bearing surface 20 for engaging said other member at a point-remotefrom the pivotal axis of the holding-member and a bearing surface for engaging said other member at a point nearer the pivotal axis of the holding member, whereby movement of the releasing 25 member in one direction effects engagement of said first mentioned bearing surface to force said holding member out of its holding position and movement of said releasing member in another direction eifects engagement of the other of said 30 bearing surfaces to exert pressure on said holding member to maintain itmovabiy in its brake holding position.

RICHARD W. BURNETT.

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