US1963115A - Releasing and holding means for car hand brakes - Google Patents

Description

R. W. BURNETT June 19, 1934.

RELEASING AND HOLDING MEANS FOR CAR HAND BRAKES Original Filed May 28, 1928 Patented June 19, 1934 UNITED STATES PATENT OFFICE RELEASING AND HOLDING MEANS FOR CAR HAND BRAKES Richard W. Burnett, Chicago, Ill.

12 Claims.

This invention relates to hand brake apparatus for railway cars and more particularly to improved mechanism for holding the hand brake in and releasing it from its brake setting position.

A principal object of this invention is to provide improved holding and releasing mechanism in which parts thereof are so constructed and arranged with relation to the normal position of the operator and with relation to the form and arrangement of other parts of the hand-brake apparatus as to insure maximum efficiency in the operation of the apparatus and also to'insure greater safety to the operator by making it impossible or at least very inconvenient for him to operate the holding and releasing means in an unsafe manner.

A further object is to provide, in hand brake mechanism having a holding pawl and a trip lever therefor, spring means adapted to cooperate with the holding and tripping members to hold the pawl in both its holding and releasing positions and `which also serves, by pressure exerted on the tripping member, to avoid excessive oscillations or accidental overthrow of the tripping lever during the rateheting of the pawl over the ratchet.

A further object is to provide spring pressed mechanism for performing the functions above noted, which spring mechanism and the cooperating parts of the holding and tripping mechanism are so formed and associated that the spring pressure, for resisting reverse movement of the lever from either of its extreme positions, is effective only when the trip lever is near the position assumed during the brake setting operation or near the position which the lever assumes during the brake releasing operation.

The invention has for further objects such other new arrangements, constructions and combinations of parts hereinafter described and claimed for carrying out the above stated objects and such other objects as will appear from the detailed description of the embodiment of the invention shown in the drawing.

This application is a division of my copending application Serial No. 281,088, filed May 28, 1928 (Patent No. 1,939,953 dated December 19, 1933) filed as a continuation in part of application Serial No. 10.248, filed February 19, 1925; and claims, among other novel combinations, the combination of a webbed hand wheel and trip lever arranged back of said wheel, disclosed but not claimed in my copending application Serial No. 109,061, filed May 14, 1926.

(CI. 18S-81.1)

The invention is illustrated in one specific embodiment in the accompanying drawing, wherein:

Fig. 1 is a front view of a railway car hand brake mechanism, with parts broken away, to illustrate the winding mechanism and the arrangement of my improved holding and releasing means.

Fig. 2 is a plan view of the mechanism shown in Fig. 1 with the hand wheel omitted and with 05 the upper portion of the housing broken away to illustrate the relative positions of the holding and releasing means, and

Fig. 3 is a fragmentary view illustrating the upper portion of Fig. 1 with the holding and 70 releasing members moved to disengage the pawl from the ratchet, but before the pawl and lever have reached their position of rest.

The type of hand brake mechanism herein shown is adapted to be secured to a vertical wall of a railway car so that the hand wheel will rotate about a horizontal axis and in a plane substantially parallel to the wall on which the mechanism is supported, although the said brake mechanism may, if desired, be arranged 30 at an angle to the wall of the car.

In the drawing the hand power mechanism is enclosed in a preferably two-part housing, the front member being designated by the reference character 10 and the back member being designated by the reference character 11. Journaled in the housing is a horizontal shaft 12 upon which is rotatably supported a winding drum 13. A chain 14, or other exible connector is attached at one end to the brake mechanism underneath the car (not shown) and is attached at the other end to the winding drum. This attachment is indicated at 15 on Fig. 1, so that a turning movement of the drum will cause the connector 14 to be wound about the surface of 95 the drum and thereby apply brake setting power to the brake rigging. The drum may be of any suitable configuration, though it is preferably of such size and shape that the first turning movement serves to effect a quick take-up in the slack and that the further movement of the drum and back members of the housing and one end of the shaft extends through the front portion of the housing and is provided with a hand wheel 18 formed with a webbed central portion which provides hand grips adjacent the rim of the wheel.

It will be seen from the above description that a turning movement of the hand wheel in a clockwise direction with reference to Fig. l, will impart, through gear 17 and gear 16, a rotary movement to the winding drum 13 in the direction indicated by the arrow in Fig. 1. This movement of the winding drum winds the connector 14 thereon in a direction to set the brakes. In Fig. 1 the winding drum is illustrated in the position which it assumes when the brakes are in their fully set position.

In order to hold the winding mechanism from reverse movement during the brake setting operation and also to permit the hand power mech-. anism to be released either instantaneously, a step by step release, or by a. graduated or retarded release under the control of the brakeman, I have provided improved holding and releasing mechanism forming the principal subject matter of this application. This mechanism comprises preferably a pawl 19, a holding and tripping member 20, an operating lever 21 and spring mechanism 22 for holding the member 20 in engagement with the pawl. The pawl 19 is preferably formed integral with a horizontal shaft 23 the latter of which is journaled in the housing in a position, preferably, above the ratchet 24. The pawl is formed with a tooth or nose piece 25 adapted to engage the teeth of the ratchet wheel.` The pawl is also provided with a tail piece 26 which acts as a stop to prevent overflow of the pawl and also acts as a brake through its engagement with the ratchet wheel. The operating lever 21 is secured to the rock shaft 27 outside of the housing in a position between the hand wheel 18a and the front portion of the housing. The webbed central portion of the wheel compels the brakeman to reach over the wheel to operate the trip lever 2l. On this rock shaft is fixed the holding and tripping member 20, one end 28 of which is adapted to bear upon the upper surface of a web 29 at one side of the pawl, the arm 28 of the member 20 being preferably of such length that its bearing point is near the pivotal axis 23 of the pawl. The other end 30 of the holding and tripping member engages the under surface of the web 29 near the toothed end of the pawl when the operating lever 21 is turned approximately 180 to the right from the position shown in Fig. l. By forcing the operating lever downwardly at the end o! its movement to the right, the nose piece 25 of the pawl 19 can be disengaged from the ratchet wheel 29 against the braking pressure existing between the pawl and ratchet. If the operating lever is turned so as to merely bring the holding and tripping member 30 against the under surface of the web 29, the brakes may be released by relieving the pressure between the pawl and the ratchet by slight movement o1' the hand wheel 19 in a direction to set the brakes, the pawl being lifted out of its holding position by the weight of the over balanced position of the lever together with the pressure of the spring yoke 32 against the rockshaft 31 at one side of the pivotal axis of said rock-shaft. If it is desired to effect a step by step release, this can be accomplished by forcing the tooth 25 of the pawl out of engagement with the ratchet and immediately permitting it to re-engage with the ratchet. If it is desired to retard the releasing action of the power mechanism, the brake-man exerts pressure downwardly on the trip lever 2l when the latter is turned to the release position. This pressure on the lever 21 compresses the spring 33 and moves the tail portion 26 of the pawl into frictional engagement with the teeth of the ratchet wheel. The fact that the holding and tripping member engages the toothed end of the pawl at a relatively short distance from the pivotal axis of the rock shaft 27, when the latter is turned to the releasing position, makes it possible to exert great pressure on the pawl to release it from the ratchet. Such arrangement also makes it practicable to exert a retarding pressure on the mechanism by forcing the tail portion 26 of the pawl into frictional engagement with the ratchet wheel. The rock shaft 27 has a section 31 which lies within the yoke 32 on a spindle 33. The spindle 33 extends within a tubular guide 34 projecting from the inner wall of the housing. A coiled spring 35 is interposed between the housing and the yoke so as to force the yoke toward the rock shaft. The portion 31 of the rock shaft 27 is preferably formed with flat side portions 36 and 37 which are preferably so formed as to be slightly oblique to the inner face of the yoke when the operating lever 2l approaches its extreme left or right movement with respect to Fig. l. However, when the lever 21 reaches its normal releasing position the surface 37 bears flat against the inner face of the yoke and prevents the Weight of the lever from moving the tail of the pawl into rubbing contact with the ratchet, such rubbing contact being effected by the brakeman pressing downwardly on the lever 2l. Ihe Obliquity of the surfaces 36 and 37 provide bearings against the inner face of the yoke at one side of the center of the shaft 27, thereby providing in effect a crank arm portion against which spring pressure is exerted when the tripping lever 21 is in the position indicated in Fig. 2 or in Fig. 3. The spring 35 therefore, exerting pressure against the rock shaft at one side of the center thereof, resists any tendency of the shaft to revolve in a reverse direction after it has been moved to the limit of its left throw and exerts pressure on the flat surface 37 of the shaft to support the pawl 19 and the lever 21 in their normal position of release. 'I'his spring pressure also serves to maintain the holding and tripping member 20 in engagement with the web 29 of the pawl. Consequently when the pawl 19 is in the position indicated in Fig. 1, the spring exerts a downward pressure on the'pawi through the holding and tripping member 20, thereby minimizing the oscillations of the operating lever 21 during the ratcheting movement of the pawl and avoiding accidental overthrow of the tripping lever.

Operation-The brakes are set by a twirling movement in a clockwise direction of hand wheel 18e, the brakeman producing the twirling movement by the use of one hand while holding on to the car with his other hand. A single twirling movement of the wheel will take up the slack in the brake apparatus and bring the brake shoes against the car wheels with some braking pressure. During this movement the ratchet wheel 24 turns under the pawl 19. The pawl rises over the successive teeth of the ratchet wheel, engagement of the pawl with the ratchet being insured by the weight of the operating lever 21 and by the pressure exerted by the spring 35. Assuming that the brakes have not been suiliciently set by this first movement of the hand wheel, the brakeman takes another hold on the wheel with his right hand and by turning the wheel in clockwise direction, revolves the winding drum 13 as far as may be necessary to create the desired braking pressure between the brake shoes and the wheels of the car.

To obtain an instantaneous release, the operating lever 21 is swung to the right until the portion 30 of the tripping member engages the under surface of the web 29. In this position the lever 21 may be forced downwardly to lift the pawl 19 out of its holding position, thereby permitting the instantaneous release of the brakes. If desired further downward pressure may be exerted against the ,lever 21 so as to force the retarding tail 26 of the pawl into frictional engagement with the ratchet, as previously described. A step by step or notching off release may be obtained by bringing about a momentary disengagement of the pawl from the ratchet wheel, followed by a re-engagement with the next tooth of the ratchet. This is accomplished by disengaging the pawl in the same manner as above described, but quickly returning the lever 21 to a position to permit the pawl 19 to fall by gravity into engagement with the ratchet.

To obtain what has been termed a graduated release, that is, a release of the brakes under the control of the brakeman, which may be desirable in driving the car, the holding and tripping member 20 is turned so that its portion 30 bears against the end portion of the web 29 of the pawl. On account of the pressure between the pawl and the ratchet the engagement of the pawl with the ratchet is not disturbed. However, as soon as the pressure between the pawl and ratchet is relieved, by giving the hand wheel 18a a slight movement of rotation in the brake setting direction, the holding and tripping member 20, by reason of the weighted end 21 of the tripping lever and by reason of the pressure exerted by the spring 35 against the rock shaft 27, will lift the nose 25 of the pawl out of its holding position and move the flat surface 37 of the shaft 31 into engagement with the inner face of the spring yoke 32 and thereby support said pawl in a position above the ratchet teeth. The braking pressure may now be controlled through manipulation of the hand wheel. The brakeman may relieve the pressure by allowing the hand wheel to turn in a counter clockwise direction and if necessary, he may again increase the pressure.

The invention is illustrated herein in one specific embodiment and the detailed description and the manner and direction in which the various parts operate to produce the desired results are made in view of the specific construction shown. Obviously the pawl and other parts of the mechanism might be arranged in different locations or otherwise modified from that shown in the drawing, wherebyr the releasing movement of the pawl might be effected by a downward or by a lateral pressure of the releasing mechanism on some part of the pawl, It should be understood, therefore, that I contemplate all such modiications in structure and arrangement and operation of the various parts which come within the scope of the appended claims.

I claim:

1. Holding and releasing means for railway car hand brakes comprising a ratchet operable in one direction during the brake setting operation, a pivoted pawl for engagement with the ratchet to hold it against reverse movement, power multiplying tripping means pivoted on an axis separate from the axis of the pawl for forcibly disengaging the pawl from the ratchet against braking pressure, and spring means engaging said tripping means to exert pressure on the pawl through said tripping means to support both the pawl and the said tripping means in their ratchet releasing positions.

2. Holding and releasing means for railway car hand brakes comprising a ratchet operable in one direction during the brake setting operation, a pivoted pawl for engagement with the ratchet to hold it against reverse movement, holding and tripping means including a hand lever operable in one direction to exert downward pressure on the pawl and in another direction to exert upward pressure against the pawl, and spring means engaging said holding and tripping means to support it in its releasing position of rest independently of its engagement with said pawl.

3. Holding and releasing means for railway car hand brakes comprising a ratchet operable in one direction during the brake setting operation, a pivoted pawl for engagement with the ratchet to hold it against reverse movement, pivoted holding and tripping means including a cam having a long arm and a short arm and manually operable in one direction to move said long arm into engagement with the pawl at a location near the pivotal axis of the pawl and in the other direction to move the short arm into engagement with the pawl at a location more remote from the said pivotal axis, and spring pressed means engaging the holding and tripping member to exert downward pressure on the pawl through said long arm and to exert upward pressure on said pawl through said short arm. v

4. Holding and releasing means for railway car hand brakes, comprising a ratchet operable in one direction during the brake setting operation, a pivoted pawl for engagement with the ratchet to hold it against reverse movement, and holding and tripping means for maintaining the pawl in engagement with said ratchet and for lifting the pawl out of engagement with said ratchet comprising a rock shaft, a cam on said shaft adapted in one position to bear down on the pawl and in another position to engage the under side of the pawl, and spring means positioned to exert pressure against said rock shaft at one side of its plvotal center when the said cam approaches the limits of either of said positions.

5. Holding and releasing means for railway car hand brakes comprising a ratchet wheel operable in one direction during the brake setting operation, a pivoted pawl for engagement with the ratchet to hold it against reverse movement, holding and tripping means for maintaining said pawl in its ratchet holding position and for supporting it in its ratchet releasing position comprising a rock shaft formed on opposite sides with flat surfaces, a cam on said shaft adapted in one position to bear down on the pawl to maintain the pawl in its holding position and in another position to engage the under side of said pawl to support it in its ratchet releasing position, and spring means positioned to exert pressure against one of said flat surfaces to support the pawl free of the ratchet.

6. Holding and releasing means for railway car hand brakes comprising a ratchet operable in one direction during the brake setting operation, a pivoted pawl for engagement with the ratchet to hold it against reverse movement, hold- Sil ing and tripping means for the pawl comprising a rock shaft, a cam on the rock shaft adapted in one position of the shaft to engage the top of the pawl and in another position of the shaft to engage the under surface of the pawl, and a spring positioned to exert force on the holding and tripping means at a point eccentric to the pivotal axis of said rock shaft to resist reverse movement of said holding and tripping means from its holding and its releasing positions.

7. Holding and releasing means for railway car hand brakes, comprising a ratchet operable in one direction during the brake setting operation, a pivoted pawl for engagement with the ratchet to hold it against reverse movement, holding and tripping means for the pawl comprising a rock Shaft. a cam on the rock shaft adapted in one position of the shaft to engage the pawl to insure its engagement with the ratchet and in another position of the shaft to engage the pawl to support it in a position free of the ratchet, a spring pressed member positioned to bear against said shaft; said shaft being provided with a flat surface against which said spring pressed member bears to support the pawl free of the ratchet in a position intermediate the limits of its releasing movement.

8. Holding and releasing means for railway car hand brakes comprising a ratchet operable in one direction during the brake setting operation. a pivoted pawl for engagement with the ratchet to hold it against reverse movement, holding and tripping means for the pawl comprising a rock shaft, a cam on the rock shaft adapted in one position of the shaft to engage the top of the pawl and in another position of the shaft to engage the under surface of the pawl, an operating lever secured to said rock shaft and normally extending upwardly from said shaft, a spring pressed member positioned to bear against said shaft; said shaft being provided on opposite sides wlth flat surfaces normally oblique to said spring pressed member and against one of which said spring pressed member bears to support the cam and said lever in a position to hold the pawl free of the ratchet.

9. Holding and releasing means for railway oar hand brakes comprising a ratchet operable in one direction during the brake setting operation. a pivotal pawl for engagement with the ratchet to hold it against reverse movement, holding and tripping means for the pawl comprising a rock shaft, a cam on the rock shaft adapted in one position of the shaft to engage the top of the pawl and in another position of the shaft to engage the under surface of the pawl, a yoke slidably supported in a guide member and positioned to embrace a portion of said shaft, a spring positioned DISCLAIMER CAB HAND BRAKES.

passais between the yoke and a fixed member to force the yoke against said shaft; the portion of said shaft embraced by the yoke being formed with at surfaces positioned on opposite sides of the shaft, whereby said bearing face of the yoke is pressed against one side of the rock shaft at a point eccentric to its pivotal axis when the holding and tripping means is engaged with the top of the pawl and bears against the flat surface on the other side of said shaft to support the pawl and cam in their released positions.

l0. Holding and releasing means for railway car hand brakes comprising a ratchet operable in one direction during the brake setting operation. a pivoted pawl for engagement with the ratchet to hold it against reverse movement, holding and tripping means for the pawl comprising a rock shaft, a hand lever for operating the same, a. cam on the rock shaft having a long arm adapted to bear down on the pawl at a point near its pivotal axis and formed with a short arm adapted to engage the under surface of the pawl at o. point near its end to lift it out of engagement with the ratchet, a yoke slidably supported in a guide member and positioned to embrace a portion of said shaft, a spring positioned between the yoke and a fixed member to force the yoke against said shaft; a portion of said shaft embraced by :he yoke being formed with a flat surface normally oblique to a bearing face of said yoke, vhcrebv said bearing face of the yoke is pressed against the rock shaft at a point eccentric to its pivotal axis when the holding and tripping means is in a position to engage the top of the pawl.

ll. Holding and releasing means for railway car hand brakes comprising a ratchet operable in one direction during the brake setting operation. a pivoted pawl for engagement wiih ino ratchet to hold it against reverse movement, niv-- oted tripping means operable in one direction to disengage the pawl from the ratchet and having capacity for further movement after the pawl is disengaged, and spring pressed means engaging said tripping means to support it in a pawl re leasing position at a location intermediate the limit of its pawl releasing movement.

12. In apparatus for manually operating railway car brakes, the combination of a hand wheel vertically arranged on the car, a shaft connected with said hand wheel, and means for holding and releasing said shaft comprising a hand operated lever arranged back of said hand wheel. said hand wheel being formed with openings adjacent the rim of the wheel to provide hand grips at said rim and with webs which compel the brakeman to reach over the wheel in order to manipulate the tripping lever.

RICHARD W. BURNETT.

RnLnAsxNe AND Hopnmo MEANs non Disclaimer filed April of Richard W. Burnett.

Hereby entere this disclaimer to claim l2 in said specification.

[Oficial Gazette May 25, 1943.]

ing and tripping means for the pawl comprising a rock shaft, a cam on the rock shaft adapted in one position of the shaft to engage the top of the pawl and in another position of the shaft to engage the under surface of the pawl, and a spring positioned to exert force on the holding and tripping means at a point eccentric to the pivotal axis of said rock shaft to resist reverse movement of said holding and tripping means from its holding and its releasing positions.

7. Holding and releasing means for railway car hand brakes, comprising a ratchet operable in one direction during the brake setting operation, a pivoted pawl for engagement with the ratchet to hold it against reverse movement, holding and tripping means for the pawl comprising a rock Shaft. a cam ori the rock shaft adapted in one position of the shaft to engage the pawl to insure its engagement with the ratchet and in another position of the shaft to engage the pawl to support it in a position free of the ratchet, a spring pressed member positioned to bear against said shaft; said shaft being provided with a flat surface against which said spring pressed member bears to support the pawl free of the ratchet in a position intermediate the limits of its releasing movement.

8. Holding and releasing means for railway car hand brakes comprising a ratchet operable in one direction during the brake setting operation. a pivoted pawl for engagement with the ratchet to hold it against reverse movement, holding and tripping means for the pawl comprising a rock shaft, a cam on the rock shaft adapted in one position of the shaft to engage the top of the pawl and in another position of the shaft to engage the under surface of the pawl, an operating lever secured to said rock shaft and normally extending upwardly from said shaft, a spring pressed member positioned to bear against said shaft; said shaft being provided on opposite sides wlth flat surfaces normally oblique to said spring pressed member and against one of which said spring pressed member bears to support the cam and said lever in a position to hold the pawl free of the ratchet.

9. Holding and releasing means for railway oar hand brakes comprising a ratchet operable in one direction during the brake setting operation. a pivotal pawl for engagement with the ratchet to hold it against reverse movement, holding and tripping means for the pawl comprising a rock shaft, a cam on the rock shaft adapted in one position of the shaft to engage the top of the pawl and in another position of the shaft to engage the under surface of the pawl, a yoke slidably supported in a guide member and positioned to embrace a portion of said shaft, a spring positioned DISCLAIMER CAB HAND BRAKES.

between the yoke and a fixed member to force the yoke against said shaft; the portion of said shaft embraced by the yoke being formed with at surfaces positioned on opposite sides of the shaft, whereby said bearing face of the yoke is pressed against one side of the rock shaft at a point eccentric to its pivotal axis when the holding and tripping means is engaged with the top of the pawl and bears against the flat surface on the other side of said shaft to support the pawl and cam in their released positions.

l0. Holding and releasing means for railway car hand brakes comprising a ratchet operable in one direction during the brake setting operation. a pivoted pawl for engagement with the ratchet to hold it against reverse movement, holding and tripping means for the pawl comprising a rock shaft, a hand lever for operating the same, a. cam on the rock shaft having a long arm adapted to bear down on the pawl at a point near its pivotal axis and formed with a short arm adapted to engage the under surface of the pawl at o. point near its end to lift it out of engagement with the ratchet, a yoke slidably supported in a guide member and positioned to embrace a portion of said shaft, a spring positioned between the yoke and a fixed member to force the yoke against said shaft; a portion of said shaft embraced by :he yoke being formed with a flat surface normally oblique to a bearing face of said yoke, vhcrebv said bearing face of the yoke is pressed against the rock shaft at a point eccentric to its pivotal axis when the holding and tripping means is in a position to engage the top of the pawl.

ll. Holding and releasing means for railway car hand brakes comprising a ratchet operable in one direction during the brake setting operation. a pivoted pawl for engagement wiih ino ratchet to hold it against reverse movement, niv-- oted tripping means operable in one direction to disengage the pawl from the ratchet and having capacity for further movement after the pawl is disengaged, and spring pressed means engaging said tripping means to support it in a pawl re leasing position at a location intermediate the limit of its pawl releasing movement.

12. In apparatus for manually operating railway car brakes, the combination of a hand wheel vertically arranged on the car, a shaft connected with said hand wheel, and means for holding and releasing said shaft comprising a hand operated lever arranged back of said hand wheel. said hand wheel being formed with openings adjacent the rim of the wheel to provide hand grips at said rim and with webs which compel the brakeman to reach over the wheel in order to manipulate the tripping lever.

RICHARD W. BURNETT.

RnLnAsxNe AND Hopnmo MEANs Fori Disclaimer filed April of Richard W. Burnett.

Hereby entere this disclaimer to claim l2 in said specification.

[Oficial Gazette May 25, 1943.]

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