US1303271A - durst - Google Patents

Description

1. AfD-URST.

EMERGENCY SAFETY BRAKE FOR ELEVATORS. APPLICATION FILED 0:21.21. I916- RENEWED Mn. 1. 1919.

1303271 Patented- 11513713, 1919.

2 SHEETS-SHEET.

' I INVENTOR wlmsssss L]&& A D6175 Z ATTORN EY m T N E V m ATTORNEY m/AZ/f 2SHEETS-SHEET Patented May13, 1919.

I LA.DURST. EMERGENCY SAFETY BRAKE FOR ELEVATORS. APPLICATIQN FILED OCT. 21. I916- RENEWED MAR. 7, I919.

WITNESSES [Jenn A. BURST, OFPORTLAND, OREGON.

nivrnnenncv SaIfET SC-BRAKE FOR. EL VATORS.

- f ,SiiecificatiblrqflettePatent" Patented May'13, 1919.

Application fi1ed 0ctober27, 191e, senainb. 128,088. Renewed March 7, 1919. Serial No. 281,291.

To all whomit may concern: a

Be it known that I, JOHN A. DURST, a citi" zen of the United States,residing at Portland,- in the county of Multnomah' and State ofOregon, have invented certain new and usefulImprovements in Emergency Safety Brakes for Elevators,of which thefollow ing is a specification;

This invention relatesto an improvement in safety brakes for elevators, and more particularly toan emergencybral're adapted to befitted in conjunctionwith an elevator and so arranged that as the elevatoris operating under normal conditions this brake mechanism is at all'times held 111 an inoperative position but as the hoisting cable ,or chain may break or is suddenly released, the brake will become operative to stop thefalling movementof the car'or lift and will maintain the s une againstdropping tothe bot tom of the shaft. 1

I An object of my invention is to provide a brake means of the type described which is so arranged that by itself it is not capable of settingto a braking position, and to arrange means along the Wall of the shaftin such a manner that as the car may be momentarily released from its suspension by the cable through slipping of'the same or is permanently released through breaking of the cable or breaking of some of ,the parts of the cable drum operating mechanismythe brake means will be gradually setand Will thus bring the car or lift to a gradual though positive stop.

A further objectis to provide means arranged in conjunction with the hoisting cable or chain attaching means for the car or lift that as the car or lift is suspended through the medium of this cable or chain the brake means is rendered inoperative, and as raising tension is exerted upon the cable or chain attaching means following the looking of the brake, the brake may then be man ually released through movement of the brake setting means. y

WVith the above and other objects in view, my invention consists in certain novel features of construction and combinations of parts which will be hereinafter set forth in connection with the drawings and then more particularly pointed out in the claims.

In the drawings y Figure 1 is a view taken transversely and horizontally through the elevator shaft and looking down upon the top of the elevator car.

Fig. 2 is a sectional View of the upper portion of the car having the brake mecha- Insm mounted thereon and which section is taken on the line 2-2 of Fig. 1. l a

Fig. 3 is a view similar to Fig.2 but showing the brakes released.

Fig. 4: is a, fragmentary detail view taken on the line H of Fig. 2. I

Fig. 5 is a detail sectional view of one of the brake shoes, i

Fig. 6 a fragmentary sectional View to show the arrangement of the 1 shoe setting means.

Fig. 7 is a fragmentary detail view to show the mounting of the shoe.

The elevator shaft is generally indicated at 1, ai1d the car orjlift by the reference character 2, it of course being understood thatthe shaft and the lift might be of any approved typeor of some special form to ing means and the mounting of the same, it

will be evident that variations might be resortedto without in any, manner affecting the successful operation of the device of my invention.

Bearings 3 and 4: are mounted on the top of the car adjacent to the sides thereof and the toggle links 5 and 6 are connected with these bearingsand have the rods 7, 8, 9, and lOmounted therein to be capable of endwise sliding movement, it being understood that aplurality of bearings 3 and toggle links 5 are provided to mount the rods 7 and 8 at one side of thecar in such a relation that theyare alined, While the rods 9 and 10 are mounted in a similar mounting at the opposite side of the car. These rods 7, 8, 9 and 10 have the brake shoes 11, 12, 13, and 14 carried on the ends thereof and secured in any suitablemanner, it being preferable that these shoes be made somewhat after the manner shown intFjigsfe and 7 so that -jthey slide 7 through *squared"bearings in the upper end in similarly formed sockets of the brake shoes, the "parts being thus so mounted that the rods are-held against turning movement.

means of screws as indicated at 15, or in any other suitable way and 1t 1s preferable that the outer faces of each of the brake Sl'lOSS'lJB provided with a roughened surface as shown -at16.. Y

7 center thereofand is made of sufiicient-size and strength that it willsupport the entire 1 weight of thecar. A yoke 18 is connected aroundthisrod or bolt 17and is mounted to r be capableof free. sliding movement along the length thereof, and a coil sprin "1;9 is

mounted between the upper sideof this-yoke 18 and a cap 2O which is 'mountedfion. the

upper end of the rod or bolt 17 and held in attheends thereof andwith the end of the oke 18 and thus as d-rawin tension is ex- 3 i a erted upon this yoke 22the pulling strain is exerted-against the spring 19. A cable receiving eye25 isformedasa part of the yoke 22 and the supporting and hoisting cable or Chainffor the elevator can. be connected through this eye; By arranging the parts as has beeniabove set fortln when the cable or chain is connected through the eye 25 and is holdingrthe car in suspension, the spring 19. willbe compressed sufficiently that the yoke 18 will bear against the lower end of the rim of thecap 20 and consequently the car will be, positively held in suspensiom but as the tensionof the" cable or chain may be slacked, or maybe released,,the springs 19 will ex- 'pand to move theyoke 18 downwardly to the position shown in Figs,2 and 4, the opposite extreme. position being shown in Fig. 3.

The yoke 18 has the bearing lugs or ears e tending th efr m .0 ppo e ides a d theoperatinglinks 27 and 28 are connected with thesebearingears to befcapable of swinging movement and at their. outer ends are ferked as' indicated at 29 and 3O sothat they will connect with the inner ends of the rods]. 8, 9 and .10, it however being under-v stood that the rodsa-re arranged to have free sliding movementthrough the forked. ends of the operating links. Brace links 31 and 32 .are connected with the operatin'g'link 27 7. adjacent to the mounting of the same in conjunction with the yoke 18' and are branched outwardly. to have their free ends received around the rods 7 and 8respectively adjacent to'the outer-endsthereof, and s milar brace links 33 and 34; are connected with the operating link 28 and are extended to have their spread ends received around the rods 9 and 10, the-connection of the brace links being such that the several rods are allowed to have the endwise sliding movement therethrough.

Rack bars 35 and 36 are mounted in any suitable manner to extend vertically along The brake shoesrmaybe secured n place by V the sides of the elevator shaft and are so positi'oned that they lie adjacent to the approximate inner ends of the sets of rods 7 and 8, and 9 and 10 respectively. The rods 7 and 8 have oppositely disposedscrew threads on the approximate inner ends thereof and a gear wheel 37 which has a somewhat elongatedsleeve hub 38 is internally screw threaded, the screw threads at the opposite ends of the bearing sleeve being right and left hand to lit the opposed threads of the rods 7 and 8. A gear wheel 39 which is similar to the gear wheel 37 and is similarly screw threaded, is mounted on the inner end of the rods 9 and 10, which rods are provided with right and left hand screw threads. These gear wheels 37 and 39 are made of such size that as the drawing tension is exerted upon the yoke 18 to raise the same, the operating links 27 and 28will swing the rods which are carried by the toggle links 5 and 6 sufiiciently inwardly that the wheels will be disengaged from the teeth of the rack bars 35 and 36, but as the drawing tension through the eye 25 is released, the spring 19 will force the yoke 18 downwardly and consequently the operating links27 and 28 together with the brace links connected therewith will cause the mrious rods to be moved outwardly in a swinging path around the pivotal connection of tho toggle links 5 and 6 with the bearings 3 and 4k in consequence of which the gear wheels 37 and 39 will be bronght to mesh with the teeth ofthe racks35 and 3.6. As the gear wheels mesh with .the teeth of the rack, downward movement of the car will cause these gear wheels to be turned upon the screw threaded inner ends of the rods 7 and 8, and :9 and 10, and as these rods of the two pairs are oppositely screw threaded, the rods 7 and 8 will be extended from their approximate position as will also the rods 9 and 10 and the brake shoes 11, 1'2, 13 and 14 will be consequently moved outwardly. Wear plates 40, 41, 42, and 43. are connected on the sides of the elevator shaft 1 and are extended vertically in such mounting that as the brake shoes are moved outwardly through the actuation of the mechanism as hereinbefore described. these brake shoes will have their roughened faces as indicated at 16 engaged against the wear plates and consequently a braking action r This locking of the brakes against the that the brakeshoes will be brought out agalnst the wear plates w th a gradual braking pressure and thus the downward movement of the car will be somewhat gradually slowed down and the car will not be brought to asudden and abrupt stop.

There is of course the possibility that the threads of thevarious rods having the brake shoes ethereon mightbe stripped orthreads within the hubs 0f the wheels 37 and 39 might be injured in such a way that the parts would not operate upon turning of the gear wheel, and also that othercauses might prevent proper operation of the parts, and to guard against such occurrences and against the holding of the brake shoes when they should be set, it ispreferable that the springs 44 be fitted around the various rods between the ends of the brace links 31, 32, 33, and

34, and the inner ends of the brake shoes 11, 12, 13, and 14 in suchrelation that as the rods may be free through any cause, these springs will force the brake shoes out against the wear plates and consequently; a braking action willybe accomplished which will inclicate the improper operation of the parts 'or thatportions of the structureare defective.

wear plates will hold the car not only against downward movement, but also will prevent upward movement of the same even when the cableor chain is again tightened sufficiently to draw the yoke 1811p against the tension of the spring 19 to a degree that the gear wheels37 and 39 are released from the meshing engagement with the teethof the rack bars 35 andBG, and therefore it becomes necessary to turn the gear wheels '37 and 39 manually or otherwise to again withdraw the rods 7, 8, 9 and 10 from the extended position in which they bring the brake shoes to the locking engagement against the wear plates. A door 45 PIQ. vided in the top ofthe car and 11118 thus possible for a mechanic or other person to go up onto the top of the car and make adjustment of a new hoisting cable or chain and after the proper pulling tension is exerted against the spring, to manually turn the gear wheels 37 and 39 to draw the rods back to substantially the relation shown in Fig. 1 where the brake shoes are again set in the inoperative position and are released from all braking action.

From the foregoing it will be seen that I have provided an emergency brake for elevator cars which is so constructed and arranged that during proper and normal operation of the elevator the emergency brake means has no effect whatever and the car may be operated and controlled without recourse to such braking means, but immediately the tension of the hoisting cable or chain is slackened as is sometimes occasioned by slipping of the ho1st1ng mechanism or by breaking of the chain or cablefthe brake means will be brought into operation and thexemergency brakes will be gradually and then positively set. to lock the car against falling movement, the operation of the parts being automatic. 1 i r While in the foregoing I have shown and described only one specific form of the invention, it will be understood thata number of changes and variations might beresorted against parts of the elevator shaft when the rods are extended, a rack bar mounted on the elevator shaft, a gear wheel having an oppositely threaded internal bore mounted on the threaded ends of said rods, the mountmg for SillCl rods being so arranged that movement of thesame to throw the gear wheel into and 'outof mesh with the teeth of the rack bar is permitted, a connection from the hoist tonormally hold the rods in such position that the gear wheel is out of mesh with the rack bar, and means to move the parts to an opposite position;

upon slacking of the hoist cable.

a 2. An emergency safety brake for elevators of the cable hoist type comprising rods' mounted adjacent to the sides of the elevator car, rack bars mounted onthe wall of the shaft, sald rods screw threaded at their inner ends and provided with brake shoes at their outer ends, gear wheels pro vided with internally screw threaded hubs mounted on the screw threaded ends of said rods, means with which the cablehas connection to normally hold said gear wheels out of mesh with the teeth of the rack bars carried on the sides of the shaft, and means to move said gear wheels into engagement with the teeth of the rack bars upon slacking of the cable to thus cause turning of the gear wheels and consequent extension of the bars to bring the brake shoes thereof into operative position.

. 3. An emergency safety brake for elevators of the cable hoist type comprising rods mounted adjacent to the sides of the elevator car, rack bars mounted on the wall of the shaft, said rods screw threaded at their inner ends and provided with brake shoes at their outer ends, gear wheels provided with internally screw threaded hubs mounted on the screw threaded ends of said I to bring the brake shoes into operative rela 'tion. r

rods, means with which the cable hasconnection to normally'hold said gear wheels out of mesh with the teeth of the rack bars carried on the sides of the shaft, means to move said gear w-heels into engagement with the teeth of the rack bars upon slacking of the cable to thus cause turning of the gear wheels and consequent extension of the bars to bring the brake shoes thereof into operative position, and wear platesarranged upon the side of the elevator shaft to have the brakeshoes-close thereagainst in the brakf ing' action. r

V An emergency safety brake for elevators of the .cablehoist type comprising a pair of rods'fo-r each side: of the elevatorcar, means by which said rods are mounted to be capable of bodily movement toward andaway from the sidesof the elevatorthereof bored and provided with right and Copies of thisv patent may be obtained for left hand screw threads mounted on the threaded ends of the rods, rack bars mount ed at the sides of the elevator shaft, operating links connected with the rods to cause movement thereof laterally,- a yoke with which the cablehas attachment so arranged that as the cableexerts tension against said yoke the rods and gear wheels will be brought inwardly from the sides of the elevator shaft, and a spring mtroducedto exert bearing tension against the-yoke in such a manner thatas the tension of the cable is slackened the gear wheels will be moved into mesh with the teeth of the rackbars and consequently the'rods will be extended from the screw threaded hubs'of the gear wheels 5. An emergency safety brake for elevators of the cable hoist type comprising a pair of rods for each side of the elevator car, means by which: said rods are mounted to be capable of bodily movement toward and away from the sides of the elevator shaft, said rods provided at their outer ends with brake shoes and at their inner ends provided with right and left hand screw threads;. gear wheels having the hubs thereof bored and provided with right and left hand screw threads mounted on the threaded ends of V the rods, rack bars mounted at the sides of the elevator shaft, operating links connected with the rods to cause movement thereof laterally, a yoke having connection with the operating links and to" which the cable has attachment so arranged that as the cable exerts tension against said yoke the rod and gear wheels will be brought inwardly from the sides of the elevator shaft, a spring introduced to exert bearing tension against the yoke in such a manner that as the tension of the cable is slackened the gear wheels will be moved into mesh with the teeth of the rack bars and consequently the rods will be extended from the screw threaded hubs of the gear wheels to bring the brake shoes into operative relation, means by which the movement of the yoke is stopped as the drawing strain of the cable is placed thereon and a positive suspension for the car is accomplished, and means against which the brake shoes work when extended to the braking position.

In testimony whereof I aflix my signature in presence of two witnesses.

JOHN A. DURST.

Witnesses:

GEO. F. VVnIsNER, Mrs. Gno. F. WEISNER.

five cents each, by addressing the Commissioner of Patents, Washington, 1L0.

Images