USRE14797E - And john p - Google Patents

Description

(l. B. MILLS ANDI. P. NIKUNOW.

Reissucd Jan. 27, 1920.

14,797'. 2 SHEETS-,SHEET I.

v I Y .w l fr smju ...Il m uw @v2.32 .3.11% E .wn u. m Q m I m @NQ I S w ATTORNEY C. B. MILLS AND 1. P. NIKONOW.

WHEEL BRAKE. APPLICATION FILEn JULYZZ, 1918.

Reissued Jun. 27, 1920.

ATTRNEY afcit'zen of the onnsmn mmm, ora-sr MCKEEsPonT,

NEW YORK, N. Y., ASSIGNORS TO WESTINGHOUSE ELECTRIC AND COMPANY, GQIPOLATION 0F PENNSYLVANIA.

PENNSYLVANIA, AND JOHN P. NIKONOW, OF MANUFACTURING WHEEL-BRAKE. l

Original No. 1,804,471, dated q To all w'om t 'may concern.'

it known that we.

CHESTER B. MILLS,

legheny and State of Pennsylvania, and John Nikonow, a citizen of Russia, 'and a resident of New York, in the county of N ew York and State of New York, have invented a. new and useful Improvement in Wheel- Brakes, of which the following is a'speoification.

O ur invention relates to wheel brakes such as `are commonly used :in connection with elevators, hoists, and' rolling mills. A

Our invention has for its object to provvide an operating mechanism for brakes of the character aboveindicated `.which is simple and eliicient in operation and which reduces the power required to operate such brakes.

In the operaion of machinery which is motor driven, of control and safety, to use brakes which are automatic in operation and effective when applied. For example, in rolling; mills and blooming mills, where frequent. stops andreve-rsals are necessary, brakes are essential for savingtime in bring-ing the motors to rest before reversing' and in assisting in accuracy of control. lu the operation of elevators and hoists. brakes not only enable the attendant to stop the mechanism at any desired point, but automatically hold the loadin caseof failure of current supply from any cause whaterer.

It has been the practice, heretofore, torelease the. brake by means of an electromagnet havingr sufficient power to overcome the .tension of heavy spring-s which hold the brake shoes against a wheel when the magnet is not energized. The magnet must be large to furnish the power required and, on this account, it constitutes a. material item of thel cost of manufacture of the brake mechanism. lt is not practicable to use a smaller magnet with al power-reduction mechanism because of the greater yrange of movement required on the/part of the magnet armature and the resultant increase of the air gap to such length that the magnet would be ineffective.

agnetpperated brakes, furthermore, are

attended with considerable noise due to the .destructive 4hammering` of the armature Specification of Reissne Letters Patent. 'Reissued t November 14, 191,6, Serial No. 752,635, filed March 7, 19-13.

reissue led July 22, 1

United States, and a resident.v .of East McKeesport, in the county of Alit is necessary, for purposesv Jan. 2v, 1920.

Application, for 918. Serial No. 246,253.

when coming into engagement with the electromagnet, and to the brake shoes coming into sudden engagement, with excessive strains, against the brake wheel and against stops Vdesigned to limit their mov'em'ent. The noise due to the first-menticned,l source is particularly objectionable in connection with niagnet brak s operated ,by alternating current.

In our invention, we employ a small elec trie motor which is connected to the brake shoes by suitable gearing mechanism and levers. AA plurality of bui'l'ev'springs servo to cushion the force operating the lbrake shoes, absorbing the energy stored inthe lever 28, hereinafter referred to, during both the forward' and reverse movement. The motor operates to release theshoes from engagement with the brake wheel in opposis tion to the force of springs which normally maintain said engagement. When power is cut off from the motor, these springs, tending1 to return the'brake shoes into engagement with the wheel, cause the motor to reverse. This would have a tendency to bring the motor to a sudden stop at the instant when the shoes come into engagement with the wheel, followed 'by a reversal of the operating forces, continuing in a. vibratory engagement and disengagement of the shoes' and the wheel, or a hunting effect, which would considerably lengthen the cycle of'operation. We avoid these' diliiculties by providingv a one-way, slip-clutch connection between the motor and the operating mechanism. i to the sudden application of the motor torque, and the sudden release of the same, are in part prevented also by the buffer springs. f

Figure l is'an end view in elevation of the brake mechanism and a' wheel to which it is applied, Fig. 2 is a view, partially in plan The resulting shocksl and strains due` which may be of leerst f structure .andy

'which rotatably support a rod 3l.

is provided with holes 5 for lfastenin bolts. Two curved levers 6 and 7 are pivotal y sufpported by a pin 8' at the center of the base .brake shoe 11 is pivotally mounted upon a support 12, the pivots being substantially. diametrically opposite relative tothe wheel 1. The levers.A 6 and 7 are normally drawn toward each other by tension springs 13,`end coils of which engage grooves 14 of eye-bars 15 having axpivotal support on a rock shaft 16 mounted 1n the lugs 9 and 10 of the lever 6. Each of the springs -13 is attached to the lever 7 by a bolt 17 having an adjustable nut 18 provided. with grooves 19 which engage the end turns of thel spring.

The bolts 17 project through suitable openings in a r'od 2() which is rotatably supported in-the lugs S) and 10 of the lever 7. the outer ends of the bolts being provided with nuts 21. A rod 22 projects through a suitable opening in t-he.rod and is retained by nuts 23. its other end being screwed into a lug 24 that has a pivotal support between the bifurcations 25 of a collar 26. which is mounted upon the. rock shaft 16 and is fastened thereto by a pin 2T. One end of a lever 28 is attached` b v mean.; of a set screw 29 or other suitable device, to one end of the shaft 16. The opposite end of the lever 28 is provided with bifurcations 30 rack 32 has an extended portion 33 that projects through a suitable opening in the rod 31 and is held in'position b v two butfer springs 34- which are retained by an abutment 35 and a nut. '36, respectively. 'lhe purpose. of the springs 34 is to do awa) with the hammer blow which would otherwise obtain'both when the brake lcvcl's are brought into cnvgagement with thc stops 5l, as explained below, and when the brake shoes are returned into engagement with the wheel by thel force of the springsl- The cushioning effect ofl theibuli'er` springs 3-1 is transmitted to the various parts through the long lever 28. preventing undue shocks and strains on the machinery, and considerably reducing the noise incident to the/operationl of magnet brakes.

An electric motor 37,- Which is preferably of the squirrel cage induction type. is mounted upon the lever 7 and has its frame 38 integral therewith.` A collar 39 having. a cylindrical flange 40, is rigidly mounted on the armature shaft 41. A sleeve 42 is loosely mounted on the shaft 41 and has a. Bange 43 betweeIrWhich and the flange y is a roller clutchN of the usual construction having rollers 44 in grooves 45 in the ange 43,. plnlon 46 having teeth 47 l which mesh with teeth 48 on the rack 32, is

lthe pinion 4G.

Normally, the springs 13-draw the levers 6 and 7 toward each other with the shoes 11 engaging the wheel 1, as shown inA Fig. l. "hen current is supplied to the motor through anysuitable .lectrical connections, thev motor shaft is rotated counter-clockwise. as shown by the arrows in Figs. 1 andi 3. The flange l() engages the. rollers 41 and rotates the sleeve l2 and the pinion 46v to actuate the rack 32 upwardly and the rack, inl turn, actuates the lever 28 to rock the shaft 16 and the collar 26 in a` cqimter-clockwise direction. The collar 26 and the rod 22 now 'act as a toggle to separate the levers 6 and the rack downwardly. The motor is rotated l backwardly by the pinion 4G and the roller clutch, and continues to rotate freely after the shoes 11 have cl'igaged the wheel l b vk rcasoirof the one-way clutch ccmnection,

thereby avoiding the causing ofl lm due vstrains upon thc parts, and tln-.frevcrsal of the operating forces, or the hunting effect above referred to` by suddenly stopping thc motor. 'The kinetic energy store'd in the motor armature during' its reversal is thereby dissipated. and the motor is further brought comparatively quickly to a smooth stop by the frictional engagement of the various parts.

The brake is arranged to release th'` whccl 1 when the curl ci* is applied to the luain motor and to hold 'the 'whccl whenthe main circuit is broken. This rarrangement is made automatic by adapting the brake motor circuit tobe closed and opened simultaneously with'J that of the main motor, orl120 bv connecting the brake motor in shunt with the main motor.

' An limportant advantage of our improvement over the devices now used, 'is that, while the stops 51 rmay be adjusted to' Compensate for the wear of the brake shoes, it need be done'only at long intervals, asy the rack allows the range of movement to be shifted along its length without any manlual adjustment. In the magnet brake, the wear i.. T his movement is limited by adjustable' stops 51 that are mounted on projections loo " Wheel, a motorliaving supporting` means inI .tionally engaging said wheel,

ofthe brake shoes causes the length Lof't-he air gap of the magnet to var and frequent' thereby made neces-` manual adjustment is sa l.Znother advantage of our invention is that the 'motoiis integral with the brake lever, which varrangement permits the entire structure .to be assembled as a= unit, thus 4avoiding .the inconvenience involved in mounting the motor separate from the brake and adjusting the connections between the twodevices. The total' ower used by the inotor is much less than' t at of a magnet because the latter` has a variable air gap, while that of the motor small and constant.

Although we i scribed one embodiment of our invention, it will bfi/understood that our invention is not connedtheret'o, or to the structural details herein shown and described,

Ve claim as our invention:

lrln combination, a wheel, brake slices adapted for frictional engagement with said common with one of said brake shoes, and int-.ins for operatively connecting said motor to 'said -brake shoes, said means comprising a rack and pinion and a plurality of levers. 2. Iii a. wheel brake, a plurality of brake shoes, a wheel adapted tor frictional engagement by said brake shoes, pivotally mounted levers for supporting said brake shoes, an electric motor. a pinion on the shat't of said motor, a slip clutch for connecting the pinion to the motor shaft. and a rack operatively connecting said pinion to said levers.

A3. In combinatio a. brake Wheel, a lever adjacent said whee having means tor engaging said wheel, and a motor on said lever having a rotatable element yieldingly operatively connected thereto. y

' 4. In combination, a brake Wheel, a. lever adjacent said wheel having means for engaging said wheeha inotorcarried by said lever and having a frame integral with said lever, and means comprising a rack and pinion motor to said lever.

5. In combination, a brake. wheel, levers on oppositel sides of said wheel, brake shoes on said levers, and a motor mounted on om` of said levers and .having a rotatable element yicldingly operatively connected to both of said-levers.

6. In combination. :i brake wheel, levers on opposite sides of said wheel, means for yildingly drawing said levers toward said wheel, a motor on one of said levers, and a spring and gear mechanism for vieldiiigly operatively connecting said motor to said levers.

7. In a Wheel brake. the combination with a Wheel, of a pair of brake shoes for fricpaii of pivotally'mounted levers for su| porting said have illustrated and de? `trictional engagement with said Y E brake shoes, an electric motor carried one ofsad levers and havin its .ne'cti com prisng a rack. d

8. In combination,

a pinion, a one-way clutch and frame integralVA therewith, and means or'operatively eon' ng-f'sald motor to said levers, said means,

k a wheel, a.l brake shoe. biased to frictional engagement. therewithya.v

motoraiid mover-running,one-way clutch for connectingsaid motor to said shoe.

9. In combination, a braking device, a reversible motor operable in one direction only to effect the operation of said device, :s ml a slip clutch connection between said device and said motor.

10. In combination, a brake wheel` a brakev shoe, means for biasing said shoe to engagement with said wheel, a motor adapted to be direction to releasel said en! vgagement and adapted to be driven by said' operated in one biasing means in the opposite direction and means permittmg continued predetermined rotation of saidmotor after said eii, ag lfe`` ment has been restablished. i

. 11. In combination. a hrakiiig; device biased in one direction, al motor for operating the same in the opposite direction and adapted to be drii-'en-thercby in said one direction and means for dissipatmg the 1neitia eiiergystored in the rotor of said motor.

V12. In combination,- a. braking devie biased in one direction and a motorfor op erating the same intlie and adapted to vbe dri-ven thereby in the one' y f opposite di rectioiii direction vand -tol be thereupon friction'ally"f" brought to a stop.

13. ln combination, ay wheel, means for:

operating the same, brake shoes adapted for' wheel, a motor and means for causing said motor to actuate said shoes without shock.

14. The combinationwith 'a' motive mechanism and a braking device therefor, of means-foi' biasing said'device in one direction,ia motor for operating the saine in the opposite direction, and means for cushioning the action of said motor: 1

15. In combination.. a wheel, brake shoe; adapted to engage isaidwlieel", a spring for Forcing said slio'cs into engagement with said wheel, :1,motor foi-releasing said engagement and means including a springfor overcoming the force of saidfirst spring.

16. The combination A plurality of pivotally mounted brake Shoes for frictionally engaging said .WheeI, an y.-lectric motor, linkage mechanism for connecting said motor to said brakeshoes, and

a slip-clutch connection between `seid mech'- f the shaft of said motor, means ACn l biased in one direction,

connecting said clutch'v element to said shoes, and means for causing said. shaft to engage said clutch clement when said motor is operated to release said. brake and for causing said clutch element to engage said shaft to rotate said motor during the resetting ot'A said bra-ke. v v

125. In combination, a brake wheel, a bra ke shoe adapted to 'engage said wheel. a stop for said shoe. a motor for actuatingsaid brakeshoe into engagement with said stop, and means for cushioning the Jforce otsaid engagement.

19. In a wheel brake. the combination with a,\\'heel, a pair of levers pivotally mounted on opposite sides of said wheel, brake shoes carried by said levers, and means for biasing said shoes into engagement with `said wheel, of toggle links pivoted to said levers,` an ai'in secured to one of said links, an electric motor, means for operatively ycon- 'necting said arm'to said motor, and means forl cushioning the operative4 force of said 'motori 20. In combination, a wheel, brake shoes adapted to engage said Wheel, means for forcing said Shoes into engagement with said gwheel, means Afor releasing said engagement,

adjacent to said vengaging said wheel, and a motor having a and means for dissipating the energy stored' by.` the action of both said two first means.

Q1. In combination, a brake wheel, a lever wheel and'having means for rotatable element yieldingly operatively connected to said lever.

22. In combination, a braking deviceJ a motor -toi' operin the opposite directii'in and said one dispring for ating the same adapted to be driven therebyY in rection, and means comprising a stopping said motor.

23. In combination,

otally mountedvon opposite sides of said wheel and provided with brake shoes, an electric motor, a pinion on the shaftv of said motor, a rack meshing with said linked to said levers, and a spring controlled bv said rack for stopping said motor.

`24. In combination, a braking device,.a stop therefor, a motor for actuating said device into engagement with said stop, and

a wheel, levers piv-v pinion and means for gagement. v

25. In combination, a brake wheel, motive me-ans therefor, a brake shoe adapted for engagement therewith, a motor fort actuating said shoe, and means for cushioning the force of said engagement.

26. In combination, a braking device, a motor for operating the same, means for ii'iechanically connecting said motor to said device, and yielding means controlled by said connecting means for controlling` the operation of said motor. 1

27. In combination, a vbraking device, a

" motor for operating the same in one direction audadapted to be driven thereby in the other direction, and av pair of springs for controlling the operation of said motor in said two directions. Y

28. In combination, a brake .biased for setting thereof,a torque motor to release said brake and to be driven thereby upon resettin thereoffand meanssupplementing the resistive force of said brake to stall said motor upon release of said brake.

29. The combination v.with a brake shoe, and an electric motor, of means for operatively'connecting said motor to said shoe, said means comprising a device operable to permit the backward rotation of said motor, upon the opening of `its circuit, without -actuating said brake shoe.

30. The combination with af Wheel, of a plurality of pivotal-ly mounted brake shoes for ,frictionallyy engaging 'electric motor, linkage mechanism for connecting said motor to said brake shoes, means for permitting the motor to rotate backwardly without actuating said mechanism.

31. The combination with a wheel', a brake shoe for enacting with said-wheel, a motor and meanscomprising a one-'Way clutch for operatively connecting said motor to said shoe, whereby said motor is permitted to rotate backvvardly by reason of its inertia without actuating said shoe.

In testimony whereof we have hereunto subscribed our naines thisA 6th day of July,

cushioning the force of said ensaid wheel, an

and

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