US1169015A - Elevator safety device. - Google Patents

Description

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I. P. DRAWBAUGH.

ELEVATOR SAFETY DEVICE.

APPLICATION FILED MAY 24. 1913.

Patented Jan. 18, 1916.

2 SHEETS-SHEET I.

awuzwtoz Mc THE COLUMBIA PLANOGRAPH 60., WASHINGTON. n. C

I. P. DRAWBAUGH.

ELEVATOR SAFETY DEVICE. APPLICATION FILED MAY 24,1913.

1 1 69,0 15 Patented Jan. 18, 1916.

2 SHEETS-SHEET 2- Am a?) THE COLUMBIA PLANoGRAPu 50., WASHINGTON. D. C-

MICE-1 ISAAC r; DRAWBAUGH, or us QUEEN, ARKANSAS.

ntnva'ron' SAFETY DEVICE.

To all whom it may come 2%.

Be it known that I, ISAAC P. DnAwBxUoI-r, citizen of the United States,residing at De Queen, State of Arkansas, have. invented certain new and. useful Improvements in Elevator Safety Devices, of which the following is a specification.

, This invention relates to an improved apparatus to be used as an emergency brake for the car or cage of an elevator shaft.

The primary object of the invention is to provide simple and inexpensive means for positively and automatically stopping the elevator car or cage should the lifting cable become broken or the operating mechanism deranged.

A furtherobject of the invention resides in the provision of pneumatic means arranged upon the top of the car or cageto act as a cushion therefor, this arrangement absorbing the shock and jolt that would otherwise be manifest were the said means not provided.

The invention still further resides in the provision of a safety attachment for elevators which may be applied to the cars or cages of the ordinary construction without altering or changing the car to any material extent. I

The above and additional objects are ac complished by such means as are illustrated in their preferred embodiment in the accompanying drawings, described in the following specification and then more particularly pointed out in the claims which are appended hereto and form a part of this application.

In describing my invention in detail reference will be had to the accompanying drawings, wherein like characters denote like or corresponding parts throughout the several views, and in which Figure 1 isa side elevation, one of the compressed air cylinders being shown in section of a device constructed in accordance with my invention, the car or cage of the elevator being broken away; Fig. 2 is a top plan view of the brake operating mechanism, the elevator guides being shown in'section; Fig. 3 is a.

section on line 33 of F ig.*2; Fig. alis an end view illustrating the arrangement of the brake shoes; Fig. 5 is a detail perspective view of one of the brake shoes; and Fig. 6 is an enlarged section on line 66 of Fig. 2.

Referring now to the drawings, wherein is illustrated the preferred form of my invention the numeral 1 designates the elevator I Specification of Letters Patent. "Patented Jan. 18, 1916, Application filed May 24, 1912. Serial No. 769,670. i

cage or .car to which is secured in any suitable manner a pair of vertically extending cylinders 2, the said cylinders being disposed upon the top of the car or cage, one near each side thereof, and provided with a pistonrod 3 havinga piston l secured to its lower extremity within the cylinder 2. The rods 3 are secured to a. suitable metallic casing 5 through the medium of nuts 6. arranged over the upper extremities of the said rods, the

latter projecting from the cylinders at the p top thereof and extending through the casing 5 as is clearly shown in Fig. 1 of the drawings. The usual guide beams 6 are positioned one upon each side of the elevator car, the said beams extending throughout the entire length of the elevator shaft for it guiding the elevator during its travel. Cut out portions 7 are formed within the extremities of the casing'5 within which the guide beams 6 are fitted, the said beams adapted to frictionally engage suitable brake shoes Sdove-tailed as at 9 within the casing ends 5, one upon each side of the cut out portions 7 formed. therein, the mechanism for operating the said brake shoes to be here.- inafter fully described.

' A shaft 10 extends across the elevator shaft and is journaled within suitable bean ings 11, thelatter being adjustably secured as at 12 to the casing 5 so as to position the extremities of the shaft adjacent the guide beams 6 of the elevator mechanism. Rollers or friction wheels Bare-keyed or otherwise secured upon the extremities of the shaft 10 and are adapted to frictionally engage the sides of the guide beams 6 for imparting H rotary movement to the shaft 10 during the travel of the elevator car throughout the length of the shaft. A governor, designated in its entirety by the numeral 14: is arranged upon the shaft 10 near one end thereof, the said governor comprising the usual weight members 15 pivotally secured to suitable arms 16 in turn pivotally secured to a bracket 17 fixedly secured to the shaft 10. A second 7 pair of arms 18 are pivotally secured to the weight members 15 and extend to a second bracket 19 slidably. arranged over the said shaft 10 and normally held in spaced relation to the stationary bracket 17 through the medium of an expansion spring 20 ar ranged overthe said shaft, one end of which engages suitable lock nuts 21 threaded on the saidshaft whileits opposite end bears against the said slida-ble bracket 19.

- levers 22 are normally supported by the v The means for operating the brake shoes 8, the said means being controlled by the r0- tation of the governofl-l,comp-rises a pair of bell crank levers 22, the saidrlevers being pivotally secured as at 23 within a cut out p0rt 0n2e Qft c sing 5, one near .ea hend "thereof or adjacent the guide beams 6. The said two levers 22 being ina'duplicate butone will be described in detail. A pair of seg- -mentajl raeks= 25 are fonmed integrally with theiibellnoranlklever 22, thessa'id raeks being arrangedin spaced relation so was to engage rack bars '26 -for ned upon the brake shoes 8 and extendingthroughout the entire length of theinner facethereof. il he said racks-25 are normally held in ,mesh with the rack bars-26' through the medium ofa t 'i g ger arm 27 broken centrally #as ;at :28 =to sperm-it pivotal movement thereof and :terininative at its lower-extremity in a longitudinally ex- -r0d"29 jonrnaled within suitable brackets30 arranged uponthe upper face of the easing 5 and extending to a point above the I said casing adjacent the -said -mem bers -15 0f the governor, the opposite end of the said rod from that of the trigger arm 27 being provided with a lever 81 adaptedto be engaged by lugs formed uponthe said :weightlineinbers 15 of-the-gow ernorasthe latter are rapidly revolved in .a manner to "be he-reina fter fully set forth. 'fl he inner or free ends of :the bell crank trigger-arm 27 of the trip meehanisnnthis arrangement holding the -racks, 25 inoperative With respect to the'rack bars 26 of the brake shoes. Spri-ng's 33 are secured to each of'the levers 22 for rocking thesaid levers 0r swinging the same upon their pivot supports '23 when the trigger-arm 27 is withdrawn from engagement with-the free ends of the said levers, the tension of the springs movingthe racks 25 and lifting :the brake shoes '8 so as to wedge the same betweenthe guide beams '6 andthe extremities :of the casing 5 as is clearlyshown in Fig. Aof-the drawings. 'To increase the frictional e11- gagement between the said shoes and the guide *beams 6 the engaging faces of the said shoes 8 are serratedas at 34:.

Having described indetail-the construction of the apparatus or device, the 1 opera- 'tion of the same will now=beifully set forth.

Should the supporting cable or rope oft-he elevator car for-any reason break, .orshould the operating mechanism become deranged, theaveight ofthe car or cage will c'ausethe same to drop or F fall, 1 this 1 movement of the car rapidly rotating the friction rollers 13, in turn imparting a like movement to the shaft 10. 'As the shaft 10 rotates abnormally fastthe weight members ofetheigovernor 14; expand until the lugs 32 thereof 1 engage the lever 31, such engagement throwing the trip arm 27 out (if-engagement with Letters Patent, is

the free ends ofthe operating bell crank levers 22. The free extremities ofthe bell crank levers being unsupported the tension ofathe springs 33 will swing the racks 25 upon their pivotal support, this movement of .theracks elevating the brake shoes ,8 and wedging the same between the-inner faces of the cut .ontiportions 7 and the guide members 6 and thus preventing further movement of the car 1.

To absorb the ShOGlCallGlmIGllBVf-B the strain upon the casing 5 themechanism carri-ed thereby, the compressed air cylinders, 2 have been provided. As thewbrakes areapplied in the manner above set forth'zthe said cylinders 2 are free toanovenponthe piston rods :which .are stationary and as the piston t is :clrawn toward the upper extremit of the said .scyl'i'nders the =.air contained within the latter is compressed thereby forming .a cushion for :the car body and preventing serious injury to the occupants thereof.

:It-will be seen fromuthe above, taken in connection with the accompanyingdrawings that the entire brake mechanism is controlled by the rotation of thefrictionmb'llers from engagement :wi-thg the :free ends 'of the operating levers .22 and that :the vprovision of 1 the springs '33, 1 disposedxas 1 they are with respect to the 1 said operating levers, -will-operate thesegmental racks 25 and vertically slidethe -rbnake shoes until :the same become wedged against :theguide beams 6 0f the elevator mechanism.

In reduction :topracticegI have found that the form of my invention, illustrated in-the drawings'and' referned to in theabove .description, :{LS the preferred embodiment, is the most efiicient and practical; yet realizing that the conditions concurrent with the adoption .of:my device will necessarily vary, I desire to emphasizethe fact that various minor changes in details of construction, proportion =-andarrangement of parts may be resorted to, 'when required, without sacrificing any ofwthe advantages of any invention, as defined in'ithe appended claims.

:HaVing-thus fullydescribed my invention, what Iclainras new;and desire to-secure by 1. An emergency brake for elevator cars including a {plurality of friction rollers, guide beams upon which the rollers ride, rack carrying brake shoes -m0va ble into and out of engagement with said beams, and means controllable by movement of said rollers adapted to engage the shoe racks to force the shoes'againstthebeams.

2. An emergency brake for elevator cars including a wedge shaped shoe,'teeth formed upon the shoe, a guide beam extending longitudinally of the elevator shaft, a segment engaging the teeth of said shoe, means nor mally maintaining the segment inoperative, means controlled through movement of the elevator to actuate said last mentioned means, and means operating"automatically to move the shoe in engagement with the beam upon a release of the control means for the segment,

3. An emergency brake for elevator cars including a pair of wedge shaped shoes, guide beams extending longitudinally of the elevator shaft, teeth formed upon the respective shoes, a segment engaging the teeth of each shoe, trip means normally maintaining the segments inoperative, and means controlled through movement of the ele vator car to actuate said trip means to provide for movement of the respective shoes into engagement with the respective guide beams, as and for the purpose set forth.

4. An emergency brake for elevator cars including a wedge shaped .shoe, teeth formed upon the said shoe, a guide beam extending longitudinally of the elevator shaft, a segment engaging the teeth of said shoe, trip 4 means normally maintaining the segment inoperative, a friction roller engaging the said. beam, and means controlled through movement of said roller to actuate said trip means and provide for movement of said shoe in engagement with said beam.

An emergency brake for elevator cars including a pair of wedge shaped shoes, teeth formed upon the respective shoes, guide beams extending longitudinally of the elevator shaft, a segment engaging the teeth of each shoe, spring actuated levers rigid with the respective segments, trip means engaging the respective levers to hold the latter inoperative, and means controlled through movement of the elevator car to actuate said trip means.

6. An emergency brake for elevator cars including a pair of brake shoes, guide beams extending longitudinally of the elevator shaft, means engaging said shoes for moving the latter into frictional engagement with the respective guide beams, trip means normally, holding said last mentioned means inoperatlve, friction rollers engaging the respective beams, and governor mechanism operable through movement of the friction" rollers to actuate said trip means.

7. An emergency brake for elevator cars including a pair of wedge shaped shoes, teeth formed upon the respective shoes, guide beams extending longitudinally of the elevator shaft, a segment engaging the respective teeth of the said shoes, said seg-- ments being actuatable to move the said shoes into frictional engagement with the operate said trip means and release said levers.

S. An emergency brake for elevator cars including a pair of wedge shaped shoes,

teeth formed upon the respective shoes,

guide beams extending longitudinally of the elevator shaft, a segment engaging the teeth of each shoe, a lever rigid with each seg ment, spring means engaging the respective lovers to actuate said segments and move said shoes simultaneously into engagement with the respective beams the mo- I ment said levers are released, trip means normally maintaining the levers inoperative, rollers adapted for frictional engagement with the respective beams, governor mechanism aetuatable through rotation of said rollers, the said governor mechanism being engageable with said trip mechanism when rotated at a predetermined speed to actuate said mechanism and release said levers to provide for movement of the respective shoes, as and'for the purpose set forth.

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

ISAAC P. DRAWBAUGH.

' lVitnesses: I

LomN Green, D. L. Cowman.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

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