US2077256A - Brake mechanism - Google Patents

Description

on 2.077.256 Searh HOOI April 13, 1937. A- F, @CONNOR 2,077,256

Y BRAKE MECHANISM Filed Feb. 14, 1934 254. PUSHNG d. FULLING IMPLEMENTS.

Patented Apr. 13, 1937 UNITED STATES 050.1 bn uuu:

PATENT lOFFICE.

BRAKE MECHANISM Illinois Application February 14, 1934, Serial No. 711,155

7 Claims.

My invention relates in general to brake-operating mechanism and has more particular reference to operating mechanism for railway car hand brakes. Y

An important objectA of the invention is to provide a winding mechanism of simplified construction facilitating assembly and hence reducing the cost of manufacturing the same.

Another important object is to provide a winding drum and associated gear for driving the same, said gear and winding drum being formed as an integral part for assembly in the winding mechanism, a further object being to form the winding drum with a helical winding track.

Another object is to construct the winding drum so as to quickly take up excess slack in the tension element or chain during the initial winding movement of the drum and thereafter gradually increase the tension force as the winding of the tension element on the drum progresses, a further important object being to form a winding drum having the aforesaid features and including an integral drum-driving gear of relatively light construction and consequently economical to manufacture without sacrificing requisite strength to resist strains and rough usage to which the mechanism may be subjected during use.

Another important object is, in conjunction with a pinion adapted for manual rotation as by a hand wheel and drivingly associated with a winding drum in a mechanism of the character mentioned in which the pinion has an associated ratchet, to provide a means in position to cooperate with the ratchet, including a pawl rotatable on a shaft and normally biased toward ratchet-engaging position wherein the shaft also is rotatable and carries a pawl-tripping finger xed thereon in order to cause the tripping finger to disengage the pawl from the ratchet when the shaft is rotated in one direction, a further object being to form the pawl-carrying shaft and the tripping finger as an integral element with one end of the shaft formed in non-circular fashion to fit into a corresponding non-circular opening in a manually operable handle whereby the pawl may be assembled on the shaft and the same assembled as a unit in building the structure and the handle finally applied to the end of the shaft.

Numerous other objects and advantages will be apparent from the following description, which, taken in connection with the accompanying drawing, discloses a preferred embodiment of my invention.

Referring to the drawing:

Figure l is a. view in vertical section taken longitudinally through the end of a railway car showing a device embodying my present invention in operating position;

Figure 2 is a view in vertical section taken substantially along the line 2 2 in Figure l in. order to show the internal construction of the device embodying my present invention;

Figure 3 is an enlarged perspective View of a combined winding drum and drum-driving gear forming a part of the device shown in Figure 2;

Figure 4 is a sectional view taken substantially along the line 4-4 in Figure 3;

Figure 5 is a view in horizontal section taken along the line 5-5 in Figure 2; and

Figure 6 is a view in vertical section taken along the line 6--5 in Figure 2.

To illustrate my invention, I have shown on the drawing a brake-operating mechanism adapted to be mounted in operating position as on the end of a railroad car II, said mechanism including a housing I3 adapted to be secured to the wall of the car II, andwinding mechanism supported within the housing I3 and adapted to be manually operated as by means of the handwheel I5 in order to tension a exible tensioning element, such as a chain I1. The tensioning element I'I is connected to the brake rigging of the car H in any suitable fashion. In the illustrated embodiment, it is attached to a draw rod I9, which, in turn, is connected to one arm of a tiltable bell crank 2| carried on the frame of the car II whereby to transfer the movement of the pull rod I9 to a rod 23, which is connected for operating the brake rigging. Obviously, any preferred equivalent of the bell crank 'powertransferring element may be employed, although it is desirable to use a transfer element of the form adapted to multiply the brake-applying force.` The brake-applying force, in the illustrated embodiment, is accomplished by forming the bell crank with a winding surface 25 having a progressive diminishing radius on which a flexible element 21 is wound as the brake-applying movement is transferred to the brake rod 23.

The housing I3 may be of any suitable construction and is formed for attachment on the wall of the car I I. The casing comprises a preferably drawn sheet metal backing plate 3l and .a cover 33, preferably formed as a casting, comprising a front wall having preferably integral means forming spaced side walls 35 and a preferably curved top wall 31, the free edges of said walls being formed for attachment to the backing plate in any convenient or preferred fashion,

so that the front of the cover is supported in spaced-apart relationship withv respect to the backing plate to form a housing provided with an opening 39 opposite the curved wall portion 31.

The windingmechanism is supported within the housing between the backing plate and the front wall of the cover with the tension element I1 extending through the opening 39 in position to connect with the tension rod I9. The winding mechanism comprises a winding drum 4I and drum-driving gear 43 preferably formed as an integral element comprising a central bearing 45 having end portions 41 and 49 respectively opposite the drum 4I and gear 43 and adapted to receive bushings 5| spaced at the opposite ends of the bearing 45 whereby to rotatably mount the element on a shaft 53. The opposed ends of the shaft 53 are secured respectively in the back plate 3| and in the front wall of the cover 33, said back plate and front wall having openings 55 of noncircular configuration to receive the correspondingly congurated ends of the shaft 53. The perforations 55 and the ends of the shaft 53 are preferably circular throughout the major portions of their peripheries, the remaining peripheral portions being flattened as at 51 so that the flattened portions face upwardly in the assembly whereby the rounded portions of the perforations 55 may afford upward support upon the ends of the shaft 53, while the shaft is prevented from rotating with respect to the casing walls by the interaction of the flattened portions 51. This arrangement is easy to effect and facilitates the assembly of the shaft and the rotatable element thereon in the casing.

The backing plate 3| also is preferably dished inwardly toward the front wall of the cover 33 where the perforation 55 is formed in order to provide a strengthening embossment 59 in the sheet metal backing plate. The bearing 45 also is preferably formed with an annular integral recess 6I between the end portions 41 and 49, which, if desired, may be loaded with a suitable lubricant, as by filling the space with absorbent material saturated with oil in order to aiord lubrication between the bushings 5| and the shaft 53.

The drum-driving gear 43 comprises a web 63 preferably extending in a plane intersecting the axis of the bearing 45 at right angles, the edge of the web 63 being formed with a peripheral rim 65 in which gear teeth 61 are formed. The winding drum comprises spaced web portions 69 formed helically with respect to the axis of the bearing 45 to define a helical winding space 1| between the webs 69 adapted to receive the tensioning element I1, one end of which is attached to an anchor pin 13 extending between the webs 69, which are formed as at 15 to provide support bushings for the anchor pin. Where a chain is used as the tension element I1, the pin 13 is threaded through the end link of the chain as shown in Figure 2 of the drawing, said link lying with its plane extending between the planes of the webs 69. The winding drum also is formed with webs 11 extending between the webs 69 and lying substantially in planes extending radially stantially parallel with the axis of the bearing 45 and lie upon the outer edges of the webs 69,

which are flattened to provide link-supportingV surfaces extending at progressively decreasing distances measured vertically from the axis of the bearing 45 throughout the circumference of the winding drum, so that when the winding drumis turned in a counter-clockwise direction, viewing Figure 2 of the drawing, the chain will be wound upon the winding drum in a direction to draw the rod I9 upwardly, viewing Figure 1, to actuate the brake rigging to set the brakes with progressively increasing force due to the decreasing distance between the chain links and the axis of the bearing 45 as the chain is wound on the winding drum.

The webs 11 are extended as at 8| on one side of the Winding drum to the web 63 of the drumdriving gear, said web extensions 8| being integral With the drum and the gear web in order to strengthen the rotatable Winding element.

The web 63 also is formed with perforations 83 in order to reduce the weightof the element and save material without sacrificing requisite strength and a perforation 85 is formed in the webV 63 in alignment with the anchor pin support openings 15 in order to facilitate the application of the anchor pin 13 between the webs 69 of the winding drum. This pin is preferably riveted in place permanently during the assembly of the mechanism.

The drum-driving gear is drivingly associated with a gear-driving pinion 81 which is mounted in the upper portions of the housing I3, that is to say, the pinion 81 is mounted within the curved wall portions 31 of the casing. The pinion 81 is also preferably formed as an integral part of a rotatable element 89, which is journaled for rotation in the back plate 3| and the front wall of the cover 33 and carries an integral ratchet 9| formed thereon.

The element 89 is formed with a bearing portion 93 journaled in a bushing 95inserted in a perforation 91 formed in the back plate 3| centrally of an embossed portion 99, which is formed in the back plate for the purpose of strengthening the same at this point. The bushing 95 also is secured in place by means of an annular-anchoring element IOI, which is seated in the ernbossment 99. The pinion 81 is preferably formed in the element 89 adjacent the bearing portion 93 in position to register with the toothed periphery of the drum-driving gear 43, the ratchet 9| being arranged on the element 89 substantially opposite the winding drum 4 I. The element 89 also is formed with a second bearing portion |03 journaled in a bushing |05, which, in turn, is mounted in a seat I 01 formed in the front wall of the casing 33. The element 89 also has a preferably integral tapered shank |09 extending outwardly of the front wall of the casing 33, said shank |09 being preferably squared to receive a correspondingly squared portion of the hand wheel I5, which is held in place on the shank |09 by means of a nut III secured on the threaded outer end II3 of the shank |09, the nut being retained inposition in any suitable fashion as by means of a cotter pin II5.

The actuating mechanism also includes a pawl I |1 co-operatively associated with the ratchet 9|, said pawl comprising a fitting rotatably mounted on'a shaft vI I9, which is journalled for rotation at one end in a perforation formed in a dished portion I2I on the backing plate and which, at its other end is journaled in and extends through a 254. PUSHING 6L PULLING IMPLEMENTS.

bearing I 23 formed in the front wall of the cover, the shaft I I9 has an end I 25 projecting outwardly of the front wall casing and formed in a noncircular fashion preferably square to fit into a correspondingly formed opening at one end of a handle I 21, by means of which the shaft II9 may be rotated in the casing.

'I'he pawl I I1 has a tip in position to engage the periphery of the ratchet 9|, and means is provided to normally urge the tip of the pawl into engagement with said ratchet, said means preferably comprising a weighted projection I29, which may be conveniently arranged to swing in the space adjacent the pawl and opposite the pinio-n so that the pawl is actuated by the gravitational effect upon the weighted portion |29, which is preferably formed integral with the pawl.

In order to raise the pawl from ratchet-engaging position, the shaft II9 carries a collar |3| lxed on the shaft adjacent the pawl, said collar having a pawl-raising finger |33`adapted to underlie the pawl so that as the handle |21 is moved in a counter-clockwise direction, viewing Figure 2, the pawl-actuating finger |33 will engage the underside of the pawl I I1 and force it out of engagement with the ratchet against the normal urge of the weighted projection |29. Y

It will be noted that movement of the pawl I I1 under the influence of the linger |33 will be limited by the curved top wall 31 so that the pawl and its projecting weight |29 cannot reach a position in which the weight |29 will urge the pawl in a direction away from ratchet-engaging position.

VThe pawl-actuating lfinger |33 also is preferably formed so that it engages the pawl before the handle |21 reaches a vertical position.

Clockwise movement of the hand wheel I5, viewing Figure 2, imparts a counter-clockwise movement to the gear 43 and the winding drum 4I Such movement, when the drum is in brakereleased position will cause the chain to be wound upon the helical winding groove of the winding drum with the link I 6I adjacent the end link of the chain resting upon the flattened edges |63 of the webs 69, which are relatively remo-te from the winding center of the drum. As the chain is wound upon the drum, the links |65, |69, |13, and |11 will progressively engage and lie upon the flattened winding surfaces |61, I1I, |15, and |19, which surfaces are progressively closer to the axis of rotation of the winding drum so that the center of the chain, during the rotation of the drum, moves inwardly toward the axis of the drum and consequently the tensioning force exerted on the chain becomes progressively greater due to the gradual reduction of the distance between the chain and the axis of the drum, so that force applied by the mechanism for the purpose of setting the brakes gradually increases'as the slack is taken up.

One of the important advantages of forming the winding drum with a helical winding track is due to the fact that as the chain is wound upon the track in setting the brake mechanism, the upper end of the rod I9 will be carried outwardly away from the car body of the car II. This movement will minimize the inclination imparted to the rod I9 as the bell crank 2| tilts during the brake-setting operation. The tilting of the bell crank 2| during brake-setting operation carries the lower end of the rod I9 outwardly away from the end of the car so that by employing a helical winding drum, the upper end is also carried outwardly with the result that the tilting of the rod I9 is minimized. This is of special advantage Deal Uli Uuml when and if the housing I3 and the winding mechanism therein is located near the bell crank Furthermore, the slack is taken up more rapidly during the initial brake-tensioning movement of the winding drum, since the chain, during this initial movement, is wound more rapidly on the drum, since its center is 'disposed at a greater distance from the axis of the drum than is the case during the final brake-tensioning movement.

It will be noted that the handle I 21, unless forcibly shifted, tends to remain in the position illustrated in Figure 2 of the drawing, thus permitting the pawl to normally engage the ratchet under the influence of the weight |29. As the hand wheel I5 is rotated in a clockwise direction, viewing Figure 2, in order to wind the chain I1 on the drum 4I, the ratchet 9| will likewise be shifted in a clockwise direction, the pawl ||1 seating in successive notches of the ratchet so as to prevent releasing movement when the hand wheel is released and holding the brakes in set position. When it is desired to release the brakes, it is only necessary to raise the handle |21 in order to disengage the pawl from the ratchet whereupon back tension in the brake rigging will rotate the winding drum in a clockwise direction and the pinion and ratchet in a counter-clockwise direction, viewing Figure 2, until the brakes are fully released.

If the handle |21 is released when to the right of the vertical plane through the axis of its pivot, its weight will return it to the position shown in dotted lines. The pawl likewise will return to ratchet-engaging position to automatically condition the apparatus for the brake-tensioning operation. If the handle, when released, is on the left hand side of a. vertical plane through its pivot, its weight will urge it to a position pressing the pawl against the curved portion 31 0f the casing out of ratchet-engaging position.

The construction is unusually simple and inexpensive to manufacture and the casing has inherent rigidity rendering it particularly well adapted to support the windingmechanism firmly and securely during rough usage to which such apparatus is subjected.

It is thought that the invention and numerous of its attendant advantages will be understood from the foregoing description and it is obvious that numerous changes may be made in the form, construction, and arrangement of the several parts without departing from the spirit or scope of my invention or sacricing any of its attendant advantages, the form herein described being a preferred embodiment for the purpose of illustrating my invention; but I do not, herein, claim the novel features of the casing, per se, since the same comprises subject matter claimed in my co-pending application, Serial No. 711,154, filed of even date herewith, Patent No. 2,016,388, issued October 8, 1935.

Having thus described my invention, what I claim. as new and desire to secure by Letters Patent is as follows:

l. A brake-operating mechanism comprising a rotatable winding drum having spaced webs forming a helical winding channel extending once around said drum with the opposed ends of the channel in staggered relationship, strengthening Webs interconnecting the spaced webs, the peripheral portions of said spaced webs extending at varying distances from the axis of the drum, and a exible element on said drum in position to be wound up in said channel when the drum is rotated.

2. A brake-operating mechanism including a rotatable winding ldrum comprising an integral element including a hub, spaced webs extending from said hub and forming a helical winding channel extending once around the drum with the opposed end of the channel arranged in offset relationship, and a web forming a driving gear extending from said hub, strengthening Webs on said hub interconnecting said gear and channelforming webs, a flexible brake-operating member connected to said drum in position to wind in said channel when the drum is rotated, said member being secured on an anchor pin mounted in and. extending between said channel-forming webs, and said gear-forming web having a perforation through which the anchor pin may be inserted into place between said channel-forming webs.

3. A winding drum comprising spaced webs forming a helical winding channel extending once around said drum with the opposed ends of the channel in overlapping relationship'.

4. A brake operating mechanism including a chain, a chain winding drum comprising a hub and spaced webs on said hub forming a helical winding channel for receiving alternate links of the chain, driving means integral on said hub for turning said drum to wind the chain thereon, and strengthening webs interconnecting said spaced webs and said driving means, said helical Winding channel having a pitch such that the chain is wound upon said drum in the direction of the tensioning force on said chain.

5. A brake operating mechanism comprising a.

link chain, a chain winding drum comprising af 'that the chain may extend in said plane after winding on said drum.

6. A brake operating mechanism including a link chain, a chain winding drum comprising a hub and spaced Webs on said hub forming a helical winding channel for receiving alternate links of the chain between said webs and the remaining links laterally on the peripheral edges of said webs, said helical winding channel comprising one turn on the drum with the opposite ends of the channel in overlapping relationship.

7. A brake operating mechanism including a link chain, a chain winding drum comprising a. hub and spaced webs on said hub forming a helical winding channel for receiving alternate links of the chain between said Webs and the remaining links laterally on the peripheral edges of said webs, said helical winding channel comprising one turn on the drum the pitch of Said channel being less than its width.

ARTHUR F. OCONNOR.

Images