US680091A - Air-brake controller. - Google Patents

Description

No. 680,09l Patented Aug. 6, I901.

c. WANDS. AIR BRAKE CONTROLLER.

(Application filed A xg. 4, 1900.) (No Model.)

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Patented Aug. 6,190].

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AIR BRAKE CONTROLLER.-

(Application filed Aug. 4 1900.)

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No. 680,09l.

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7 UNITED STATES PATENT OFFICE.

JOHN C. WANDS, OF ST. LOUIS, MISSOURI.

AlR-BRAKE'CONTROLLER.

srncrnrcarrou forming part of Letters Patent No. 680,091, dated August 6, 1901.

Application filed August 4, 1900. Serial No. 25 ,914. No model.)

To all whom it may concern:

Be it known that I, JOHN C. WANDS, a citizen of the United States, residing at St. Louis, in the State of Missouri, have. invented certain new and useful Improvements in Air- Brake Controllers; and I hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, in which Figure l is a top plan view of devices embodying my invention shown in connection with an air-brakecylinder, its piston-rod, portions of the'cylinder levers, and the tie-rod connecting said levers. Fig. 2 is a side elevation of the same, showing the devices as attached to the bottom of a car. Fig. 3 is an enlarged partial View in plan of the lefthand end of Fig. 1, showing the screw-housing, spring-housing, and bracket which supports thesame, the latter in transverse section, the section being taken on the line 3 3, Fig. 4. Fig. 4 is an enlarged side view of the left-hand end of the devices as shown in Fig. 1, the bracket and spring-housing being in elevation, the -sliding fulcrum-block broken away, and the screwhousing in longitudinal section on the linea 4, Fig. 1. Fig. 5 is an enlarged partial end view of the devices viewed from the left of Figs. 1 and 2, parts broken away to show the paWl-and-ratchet mechanism for actuating the feed-screw.

Like symbols refer to like parts wherever they occur. I

My invention relates to that class of devices sometimes termed slack-adjusters, which have for their function the automatic elimination of slack from brake systems, whether the said slack arises from shoe Wear, stretch, or other cause. As is well understood by those skilled in the art, slack or lost motion in a brake system incident to service wear on shoes,*&c., and which is practically immaterial in hand-braking, is of vital importance in power-braking, where the slack is multiplied back onto the air-brake piston and may reach such an extent as to exhaust the working stroke of the piston without setting the brakes. This class of devices as heretofore generally constructed depends on using the excessive travel of some portion of the brake system distant from the power devices to actuate mechanism which shall either shorten up the connections between the levers of the systems or change the relative position of the fulcrums of the levers of the brakerigging, and such constructions are more or less liable to be rendered inefficient by unequal wear on the brake-shoes and other causes which vary the paths of travel of the pull-rods and the positions of the levers of the brake system, a slight variation of position being in many constructions sufficient to derange the operation of the devices. overcome the several objections, I combine with the fulcrum of the cylinder-lever mechanism actuated either by the piston-rod or lever connected thereto, whereby any excessive travel of the piston-rod causes such movement of the cylinder-lever fulcrum as shall eliminate the slack from the system at a point adjacent to the power devices, and such a construction embodies the main feature of my invention.

In carrying out my invention I prefer to employ in combination with a cylinder-lever a sliding fulcrum-block, a feed-screw for moving the same, pawl-and-ratchet mechanism for actuating the feed-screw, a connection between the pawl-and-ratchet mechanism and the piston-rod of the air-brake or like power mechanism,and retracting mechanism whereby the adjustment is effected on therelease or taking off of the brakes, and the same embodies a secondary feature of my invention.

There are other minor features of invention, all as will hereinafter more fully appear.

I will now proceed to describe my invention more fully, so that others skilled in the art to which it appertains may apply the same.

In the drawings, A indicates an air-brake cylinder; a, its piston-rod; B and B, cylinder-levers with which the brake system may be connected in the usual and well-known way, and O the tie-rod connecting the cylinder-levers, one of said levers B being connected with the piston-rod a, which operates the brake system, and the other,B,fulcrumed on the cylinder, the general arrangement chosen for purposes of illustration being substantially that of what is termed passenger equipment.

In carrying out my invention the fulcrum of the cylinder-lever B is made adjustable a at one end and may be supported at theother by a bracket 2, which may be attached to the bottom of the car in line with theairbrake cylinder A. The feed-screw housing 1 is slotted below to receive and guide the sliding fulcrum-block 3, its inner and outer ends being tubular to retain and journal the feed-screw which moves the fulcrum-block 3.

3 indicates a sliding fulcru m-block,to which one end of the cylinder-lever B'- is pivotally connected, said sliding fulcrum-block having a nut or threaded bore, through which the feed-screw 4 passes. Loosely journaled on the outer end of the feed-screw 4 is a hollow pulley or sheave 5, carrying in its interior .a

pawl 6, adapted to engage a ratchet-wheel 7, attached to the end of the feed-screw within the hollow sheave, whereby'the sheave may turn loosely on the feed-screw in one direction, but in its reverse movement causesthe feed-screw to turn with it. The projecting end of the feed-screw 4 is provided with an attached sprocket or hand wheel 4, and the projecting end of the pawl-shaft is provided: witha thumb-piece 6 whereby the pawl 6; may be disengaged from the ratchet 7 and the feed-screw turned manually when the sliding fulcrum-block 3 is to be adjusted for the applicationtof new for worn brake-shoes or for like purposes.

8 indicates a spring case or pocket carried by or mounted on the bracket 2, which supequivalent means for retracting the bridle. or flexible connection between the piston-rod Between the sheave5 and a and sheave 5. the spring-case 8 the bracket 2 carries a pulley 9, around which the flexible connection or bridle passes, and a pulley 10 for a similar purpose is interposed between the sheave 5 and the piston-rod a.

Arranged parallel with the path of the gpiston-rod a and at the limit of its normal working travel is a rock-shaft 11, properly supported-as, for instance, from the car-botto1nand said rock-shaft is provided with one arm 11*, which stands in the path of the piston-rod, and a-second arm 11", which may have an eye and with which theilexible connection or bridleleading from sheave or .pulley 5 is connected, either directly or preferably through an intermediate pull-rod 12, which may pass through a guide 12 or be otherwise suitably supported against sagging.

13 indicates a bridle or flexible connection between the sheave 5 and the rock-shaft 11, which latter is actuated by the excessive travel of the piston-rod a and in turn actuates the sheave'5 in one direction. The bridle or flexible connection 113 is connected at one end to the arm 11 of the rock-shaft and after passing over pulley 10 is connected at an intermediate point to the sheave or pulley 5,

then passes over pulley 9 on bracket 2 and has its other end connected to the retractingspring inclosed within the spring-case 8, the length of the several connections 12 and 13 being such that when the rock'shaft 11 is rotated by excessive movement of piston or the sheave-5 will be rotated (and will turn loosely on feed-screw 4) and the spring within the spring-case 8 will be put under-sufficient tension to retract the bridle (or connections 12 and 13) and reversely rotate the sheave 5 when the piston a makes its instroke or the brakesare released.

The construction and combination ofthe devices being substantially such as hereinbefore pointed out, they will operate as follows to eliminate slack or lost motion from the brake system: Thelocation'of rock-shaft 11 and its arm 11 being in the path of and at the-extremeof the normal outward travel of'the piston a, and the length of the flexible connections or rod 12 and'bridle 13 between the arm 11 of the rock-shaft 1'1 and the sheave 5 and between the sheave 5 and the retracting-spring housed in spring-housing 8 being such that when the rock-shaft is actuated by the excessive travel of the piston a the sheave 5is-rotated (loosely) on the feedscrew 4, the pawl 6 sliding over the teeth of ratchet 7, andthe retracting-spring in casing '8 being put under tension, (or compression,

as ;the case may be,) it follows that the release of the brakes or inward movement of piston at will permit the operation of the retracting-springto reversely rotate the sheave 5 and through'the ratchet mechanism 6 7 1'0- tate the feed-screw 4, thus causing a movement of the sliding :fulcrum-block 3 proportionate to the excessive movement of piston a in its outwardstroke. This movement of the fulcrum-block 3 so changes the position of the fulcrum of the cylinder-lever B as to compensate for any wear or lost motion in the brake system and thereafter reduce the movementof the piston a, to its normal travel.

Having thus described my invention, what I claim, and desire to secure by Letters Patout, is-

1. In an air-brake controller, the combina* 'tion with cylind er-levers and an air-brake piston, of a movable fulcrum for one of the cyl-' inder-levers other than that connected with the piston-rod, means for causing the travel of said movable fulcrum, and a contact connection arranged in the path of the piston= rod for transmitting the excessive travel of the piston to the devices which actuate the movable fulcrum; substantially as and for the purposes specified.

2. In an air brake controller, the combina tionwith-cylinder-levers and an air-brake pis ton, of a movable fulcrum-block for one of TIO the cylinder-levers, a feed-screw for actuating the movable fulcrum-block, pawl-andratchet mechanism for actuating the feedscrew, and a bridle or flexible connection interposed between the pawl-and-ratchet mechanism and the air-brake piston; substantially as and for the purposes specified.

3. In an air-brake controller, the combination with cylinder-levers and an air-brake piston, of a movable fulcrum-block for one of the cylinder-levers, a screw-feed and a pawland-ratchet mechanism for actuating the movable fulcrum-block, a bridle or flexible connection between the pawl-and-ratchet mechanism and the air-brake piston, and means for reversely actuating the pawl-andratchet mechanism on the instroke of the piston; substantially as and for the purposes specified.

4. In an air-brake controller, the combination with cylinder-levers and an air-brake piston, of a feed-screw housing mounted on the head of the air-brake cylinder, a sliding fulcrum-block for one of the cylinder-levers,

and a feed-screw carried by the feed-screw housing, a loose sheave, and a pawl-andratchet mechanism carried by the feed-screw, a rock-shaft, a retracting-spring, and. suitable connections between the rock -shaft, sheave, and retracting-spring; substantially as and for the purposes specified.

5. In an air-brake controller, the combination with cylinder-levers and an air-brake piston, of a movable fulcrum-block for one of said levers other than that connected with the piston, a rock-shaft arranged in the path of the piston-rod,and means for actuating the movable fulcrum-block from the rock-shaft, i lubstantially as and for the purposes speci- In testimony whereof I affix my signature, in presence of two witnesses, this 30th day of July, 1900.

JOHN C. WANDS.

Witnesses:

WM. H. SCOTT, J. G. ALEXANDER.

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