US1132770A - Safety device for elevators. - Google Patents

Description

E. L. GALE, Sx. SAFETY DEvIL` Fon ELEVATORS.

APPLIUAI'ION FILED APR. l1. 1908.

Patented Mar. 23, 1915.

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Patented Mar. 23, 1915.

APPLICAWU ,f

E. LIGALE, SR. SAFETY DEVICE POR ELEVATORS` APPLICATION `1I.EDAi"R.11. 1908.

1, 1 32,770. Patented Mar. 23, 1915.

SSHHIITSWSHBET 3. lll-j n l UN'TEE STATES PATENT FFICE.

ERNEST L. GALE, SR., OF YONKERS, NEW YORK, ASSIGNOR T0 OTIS' ELEVATOR COMPANY, OF JERSEY CITY, NEW' JERSEY, A COREORATION OF NEW JERSEY.

SAFETY DEVICE FOR- ELEVATORS.

Application filed April 11, 1908.

T0 all rr/rma it may concern.'

Be it known that I, Enno-vr L. GALE, Sr., a citizen of the United States, residing at Yonkers, in the county ot \Vestchester and State of New York, have invented a new and useful Improvement in Safety Devices for Elevators, of which the following i. a specification.

.My invention relates to safety devices for elevators, and more particularly to that torni of brake mechanism in which gripping Jaws carried by the elevator car are arranged t0 grip guide rails extending along the sides of the elevator sha'it.

Une ot the objects of my invention is to provide siniple and etlicient means for automatic-ally operating an elevator safety device of the character referred to, when the car approaches either ol its limits ot trav el.

Another object ot the invention is the provision of means for positively locking the brakes in their applied positions whenever the hoisting ropes become slack, and for holding such brakes locked until the tension in the ropes is restored.

A further object of the present invention is to provide in connection with a safety device automatically operated by governor mechanism upon excessive speed of the car, automatic means operated at the limits of travel of the car in either direction for operating said safety device independently ol the governor mechanism.

Other objects oi' the invention will appear hereinafter, the novel conlbinations ot elements being set forth in the claims.

A sa letv device having brake mechanism ol' the character referred to is shown, for example, in the patent to John, No. 665,2Q5, granted January 1, 1901, for an improvement in emergency brakes, and the present invention involves various improvements in meansl for controlling and operating such brake mechanism,

hReferring to the drawings, VFigure 1 is a general view, largely diagrammatic, of an elevator system embodying one, form of my invention; Fig. 2 is a. part sci-tional elevation on an enlarged scale o'l an elevator rar to which my invention applied: Fig. 3 is a plan view of brake mechanism shown in Fig. 2; and Fig.-l is a detail view ot a, niodification.

The elevator car is raised and lowered Specification of Letters latent.

Patented Mar. 23, 1915.

serial No. 426.436.

by means ot two or more cables B, C, attached at one end to the car, passing over the overhead sheaves 11, 12, the driving sheave 13 ot' the motor M, and the overhead sheave 14, and attached at their other ends to the counterweight 5. Any type of hoistng apparatus may be used.

The motor M, .which maybe of any type ada] ted for operating elevators, is here shown as a direct current electric motor adapted to receive current from the positive and negative mains (designated -land connected to any suitable source of direct current supply. The mechanism for controlling the motor comprises the potential switch l), the reversing switches R, R, an accelerating magnet K, a sectional starting resistance L, and a manual controlling switch S in the car.

The emergency brake mechanism as shown on the drawings embodies a construction substantially like that Set forth in the patent to John, ilo. 665,225, before referred to, and to which reference may be had for a detailed description of said mechanism. The brake mechanism carried by the car, and here shown as located beneath the tloor ot the car, comprises pairs of pivoted jaws G, 6 adapted to grip the vertical guide rails or l`-irons 7, 7 extending vertically through the elevator shaft on opposite sides of the car. Between the two pairs of clamping jaws is a safety drum D, having a longitudinal bore screw-threaded to receive the threaded ends of the shafts E, F. lin line with the shafts E, E are shafts (i, G having cams lll, Il adapted to operate the clamping jaws. The adjacent ends of the shafts (l, E, and G', E' are screw'- threaded to receive the internally threaded sleeves il, N. The shafts G, E, E', (i are all secured against rotary movement and have their adjacent ends reversely threaded, so that if the safety drum D or the sleeves N, N' are rotated in one direction, the cams ll, ll will be moved outwardly to operate the gripping jaws, and it rotated in thc reverse direction. the cams will be retracted thus relieving the gripping eliect of the jaws. An endless rope or cable 8 passes around a lower pulley 9, held dow vard by the spring 10 to keep the rope t. t, and an upper pulley The pulley 15 s connected to a governor, such as shown in the patent to John above referred to, and which is tion sheave 17 and connected at 18 to the cable 8. Any undue speed of the car will cause the governor to operate a grip to stop the cable 8, whereupon theA cable 16 will rotate the safety drum D and apply the brakes. A device for applying the brakes manually in case of an emergency is provided, as follows: In a convenient position within. the elevator car is an emergency lever 18 secured to a rock-shaft 19, having rock arms 20 connected by links 21 to arms 22 formed on or secured to the sleeves N, N'. By moving Vthe'emergencylever 18 to the right (Fig. 2), the sleeves N, N are rotated in a direction to move the cams outward and apply the brakes.

The various parts thus far pointed out are not new, and form no part of the present invention, except as combined and associated with the various novel features hereinafter described.

Secured to the safety drum D, or formed integral therewith, is a ratchet wheel 23. A pawl 24 mounted for longitudinal movement in guides 25, is adapted to engage the ratchet wheel 23 and prevent backward r0- tation. A bracket 26 secured to the top of the elevator car, carries direction sheaves 27, 27', beneath which the cables B and C pass and extend in an approximatelyhorirontal direction to the edges of the car where they are secured. Pivoted to the roof of the car beneath the cables are levers 28 and 28', having rollers 29 at their inner ends. Springs 30 hold the rollers 29 in engagementwith the cables' B and C. The outer ends of the levers 28,28' are connected by cords or links 31, 31 to the horizontal arms of bell-crank levers 32, 32', respectively. The other ends of the bell-crank levers are connected to the pawls 24 and 24'. The pawl 24 vis similar to the pawl 24, and is located in position to coperate with a vratchet wheel 23' carried by the sleeve Y. The cables B and C, when taut, hold the pawls retracted as shown, but when the cables are slack the springs 30 pull the outer `ends of the levers 28, 28 downward and permit springs 33 to move the pawls into engagement with the ratchet wheels. The springs 30 maybe omitted, if desired, the springs 33, if made the proper strength, being suiiicient to operate the pawls.

In order to apply the brakes automatically as the car approaches the upper and lower limits of its travel, I provide the mechanism now to be described. y

At the lower right-hand edge of the car (Figsl and 2) is pivoted a lever 35, the

upper end of which carries a roller 36 in position to engage the stationary cams 37, 37 as the car nears its limits of travel. The lever 35 forms a catch to hold a weighted lever 38, pivoted at 39, in the osition shown with the weight 40 raised. ivoted at its lower end to the lever 38 is a link 41, slotted at its upper end to receive a '-pin 0n the end of a rock-arm 42, secured to a shaft 43. The shaft 43 carries at its ends toothed wheels 44 and 44', meshing respectively with pinions 45, 45' secured to the sleeves N, N'. Whenever the roller 36 engages either of the cams 37, 37', the catch 35 is released from the weighted lever 38 which immediately operates through the connections just described, to rotate the sleeves'N, N and apply the brakes. The pin-and-slot connection between the links 21 and arms 22 permits this automatic operation without moving the manual lever 18. Irikewisefthe pin-and-slot connection between the link 4l and arm 42 permits the brakes to be applied manually and without unlocking the weighted lever.

In connection with the emergency brake mechanism just described, I may 4provide means for automatically cutting off the current from the motor and applying the motor brake whenever the emergency brake is. applied. This result is accomplished in the present instance by opening the circuit of the potential switch magnet when the emergency is applied. To this end a switch V comprising stationary contacts 47, 47' and a bridging contact 49, is connected in circuit with the magnet'coil 48 of the potential switch. The contact 49 is carried by an insulated stem 5() extending into' the path of one of the gripping jaws, and adapted to lift the contact when said jaw is operated. This switch might, of course, be connected for operation to any suitable moving part of the emergency brake mechanism.

A general statement of the operation of the entire elevator system will now be given to bring out more clearly certain features of the invention.

The potential switch P may be closed by means of the handle 52, which will close a circuit from the positive main through contacts 53, switch V and magnet coil 48 to the negative main, which circuit will remain closed during the normal operation of the elevator. The shunt field circuit will also be closed through wires 86 and 87. To start the car, the controller switch S is closed by moving the-lever 54 onto either contact 55 or 56, depending on the direction the car is t0 be moved. If lever 54 is moved to the left, a circuit will be closed through the reversing switch R as follows: from the positive main through contacts 53, wire 57, switch arm 54, Contact 55, wire 58, magnet coil 59 of the reversing switch R, contacts 60 to the negative main. The reversing switch will now be closed and establish a circuit through the motor M, as follows: from the positive main through contacts 53, wire (31, starting resistance L, wire (32, centacts 63, 64.-, wire G5 to the motor, through the motor windings, wire 66, contacts 67, 68, wire G9, and contacts 60 to the negative main. At the same time a circuit is'closed through the magnet coil of an electromagnetic brake lV. rlhis circuit is as follows: from the positive main through contacts 53, wire 6l, magnet coil 70, Wire 71, contacts 72, 67, 68, wire 69 and contacts 60 to the negative main. rThe coil 70 being excited will lift the brake shoe 73 and permit the motor to run at slow speed, the starting resistance L being at this time in the motor circuit. The accelerating magnet K which has its vri u ding connected across the motor terminals will operate in a well known manner to successively close the switches 1, 2, 3 and at and gradually shortcircuit the sectional starting resistance L as the speed of the motor increases, permitting the motor to run up to full speed, To stop the motor in the normal operation thereof, the switch S is opened, which permits the reversing switch R tc open. and cut off current from the motor and brake magnet coil 70 so that the brake W will be applied and the moving parto brought to rest. If the switch lever 34 is moved to the right, the reversing switch R will be operated and close a circuit through the motor in the reverse direction, and thus reverse the motor.

The electric system of motor control just described is susceptible of numerous modifications and additions known to those Askilled in the-art, and is simply illustrative of one of the many systems of control which may be used in connection with my invention.

lf. at any time, the speed of the car becomes excessive, owing to an undue speed oi the motor, slipping or breaking of the cables. or other cause, the cable 8 will opcrate as before explained to rotate the safety drum D and apply the gripping jaws to the guide rails 7, 7. At the saine time the gripping jaws 6 will lopen the switch V, causing the potential switch P to Open and cut off all current from the motor and the brake lV, thus aiding in bringing the car quickly to rest, and, in case the hoisting cables are broken, preventing the motor ruiming independently of the car.

By operating the hand lever 18, the opera` tor iy apply the emergency brake zu, any time without interferingr in any way with the automatic devices. In case the manual and :uitomatic devices are operated simultaneously, their effect is simpiy added. as the cams ll and ll are moved oiftward to a greater extent. .lf the car is at any time carried beyond its normal limits of trim ci se pawls 24, 24 lock the safety drum D and 75 the sleeves N and N' against backward rotation. This is an important feature, as it absolutely prevents the operator from slaclving the gripping jaws and permitting the.

car to drop, as might otherwise occur, before the cables have been tightened. It also overcomes a positive evil found in connection with devices now in common use, in which the gripping jaws are released by ineans of a lever pin inserted through an opening in the floor of the car and engaging openings in the periphery of the safety drum D. lVith the latter arrangement, the operator may, when there is slack in the cables or when they are broken, rotate the safety drum backward step by step until the car con'nnences to drop, and then fail to remove the lever from the safety drum. As the lever prevents the drum from being rotated forward to again apply the brake, there is nothing to prevent the falling of the'caand consequent disaster. The present invention vovercmnes these objections and insures tight cables and consequent support for the car when the gripping jaws are released. The pawls 2.4, El permit a free forward rotation of their rate-het wheels so that they cannot hinder thc tightening of the gripping jaws.

ln Fig. *t l have shown a modified construction by which the limit stop mechanism is caused to operate whenever the safety drum is automatically operated. AS here shown, a hell-crank lever 80, pivoted at h1, has one arm extending down behind a lug 31'/ formed on the catch lever 35. The other arm of lever 5.() carries a roller 853, beneath which the safety drum cable 17 passes. When the {overnor cable 8 operates to place tension on the cable 17 and rotate the safety drum l), the lever 8() releases the catch lf' and permits the limit safety mechanism to operate independently of (he safety drum. flhis insures the automatic applica- Lion of the brakes, even in case the safety drum l) should stick or for any other reason fail to operate.

I wish not to be limited to the exact constructions disclosed, as various changes in the details oi' construction and arrangement of parts might be made wit-hout departing from the spirit and scope of the invention.

`\\"hat l claim as new and desire to secure hv uct-ters latent of the United States is:-

i. ln an elevator, the combination with a car, of a motor, a hoisting cable, a bra-ke,

4applying the brake,

means independent of the hoisting cable for applying the brake, and means held inoperative tension on the cable forlocking the brake in applied position.

2. In an elevator, the combination with a car, of hoisting cables, a brake, speed controlledneans to apply the brake, and means to lock the brake in applied position, upon release of tension on the cables.

3. In an eleyator, the combination With a car, of hoisting cables,l a brake, means independent of the hoisting cable for'apply- 'ing the brake, and a device associated with said cables for automatically locking the brake.

Ll. In an elevator, the combination with a car, of a motor, driving connections between the car and motor, a brake, appliances for operating the brake independently of said driving connection, and means controlled by said driving connections for locking the brake in operated position.

5. In an elevator, thecombination with a car, of a motor, a cable, albrake, speed controlled brake o )era ting mechanism, and means controlle l by the cable for locking. said mechanism.

G. In an elevator, the combination with a car, of a motor, a cable, a retarding device for the car, specd'controlled appliances for operating said device. and means controlled by the cable for holding said device in an operated position.

,7. In an elevator, the conibination-with a car,`0f a motor, a cable, a brake rafried by the car, means for automatically applying said brake when thev speed of the car beccnies excessive, and appliances 'for preventing,r the release of the brake while there is slack in the cable.

8. In an elevator, the combination with a car, of a motor, a cable, a brake carried by the car, manually operable mechanism for and means held inoperative by tension on the cable, but automatically operable whcn the cable ais s lack to prevent release of the brake.

9. In an elevator. the combination with a car, of a motor', a cable, gripping jaws carried .by the car, stationary members in the elevator shaft` mechanism for operating said jaws to grip said members, and a slack cable device for preventing release of the jaws when there is slack in the cable.

10. Inan elevator, the combination with a motor, of'a car, a cable, gripping jaws, a 'safety drum, operating connections between the' drum and gripping jaws, means .for automaticallyfrotating the 'drum and operaring .the gripping jaws when the speed Qt the car becomes excessive, ratchet teeth car ried by said drum, a pawl, mechanism betvveen the pawl and cable forfholding :ne pawl inoperative .when the. cable is' nndei tension, and means for moving the pawl into preaches its limit 12. In an elevator, the combination with a v car, of a motor, a suspension cable secured at one end to the car, a. direction sheave carried by the car :and with which the cable engages, a movable member carriedby the the brake mechanism car, means for holding said member in contact with the cable between said sheave and the point of attachment oi the cable to the car, and brake mechanism controlled by saidA member.

13. In an elevator, the combination with a car, of driving mechanism therefor, a brake carried o v the car, and mechanical means l'or auton'iatically operating the brake with gradually increasing pressure when the car is carried beyond its normal limit of travel in either direction..

14. In an elevator, the combination with a ear, of hoisting mechanism, a retarding device arried by the car, means for operating said device when the speed of the car becomes exc-e. live, and additional means for autoinaticallj,- operating said device as the car approaches its limit of travel.

l5. ln an elevator, the combination with a car, of hoisting mechanism, a brake carried by the car, a. manual device for operatingr the brake, and means for operating the bra lie automatically with gradually increasingr pressure as the car approaches its limit of travel.

1G. In an elevator, the combination with a car, of a motor, a cable, a brake carried by the car, means for automatically applying the brake as the car approaches its limit of travel, and a device controlled by the cable for locking the brake in its applied position while there is slack in the cable.

1T. In au elevator, the combinationwith a car, of hoisting mechanism, a brake carried by the car, speed controlled means for operating the brake, additional brale operating m ans, operating means inoperative throughout the normal travelof the car, and a stationary cam in the path of movement of! said trip,.

1S. In an elevator, the combination with a car, of hoisting mechanism, al brake carried by the car, a manually operabl'efflever; brake operating mechanism ,betweeifsaid lcver and the brake and means cooperating with a poition'of said mechanism for autoallyl increasing pressure as the car apof traveh 19. In ari elevator, the combination with ggcar, ofhoisting mechanism, aybrekecarf a trip to hold said additional vmatically operating the brake with graduried by the car, a Stationary electromagnetic brake for the hoisting,r mechanism, means for operating the car brake at preetermined points in the car travel, menne for anton matically opening` the energizing circuit of the stationary brake when the car brake is operated.

20. In an elevator, the combination with a car, of hoistingr mechanism, a brake carA ried by the car, a stationary electromagnetic brake, mechanism for tnieintiingh the cnr brake at predetermined` points in the car travel, Ineens for automatically opening` the circuit of the stationary brake when Seid mechanism operated, enti menne for con trolling the ooeration of the stationary brake independently ol the operation ol' the car brake.

2l. In an elevator, the combination 'ith a car, of a motor, dririnT conncitifiins be tween the car and motor` a brake carried by the car, an electro-magnetic brake, a circuit for Said electro-magnetic brake con trolled by said car brake, and means for simultaneously controlling the operation el' the motor and both ot' said brakes regardless of the direction of car travel.

22, In an elevator, the combination `with a car, of hoisting mechaniSn'i, a car brake, an electromagnetic brake `for the hoisting mechanism, means for Sinniltaneonssly operating said brakes, and menne l'or operating one of said brakes at predetermined pointe in the car travel..

23. In an elevator, the combimition with a car, of hoisting n'icchanism, acar brake, an electromagnetic brake l'or the heieting mechA anism, mechanism for applying the ca r brake for both directions; ot' car travel, means for effecting the operation oi the electromagnetic brake when saiil mechanism optiated, and independent means for controlling' the circuit of the electromagnetic brake.

24. In'an elevator, the combination with a car, of an electric motor, connections lietween the car and motor, a cnr hrnlrc, :in electromagnetic brake for the motor, mechatnism for operating the car brake, automatic means for opening the circuits ol the motor and brake magnet when said mechanism is operated, and means for operating the car brake at predetermined points in the car travel.

Q5. In an elevator, the combination with a car, of a motor, a car brake, an electromagnetic brake for the motor, means for independently operating said brakes independently ol the direction of car travel, a switch controllin the cir-:nit of the electromagnetic larme, unil means for automatically operating t'ahl switch when the car brake is operated.

21". In an a car. an rent supply, a

Stor. the combination with i. l potentn switch between the mote intl said iice of Supply, a brake carried hy the car, n @uns for operati-ng' Said hrzilse regni-dices: of the direction of car travel, cnil means for ell'ecting the opening iii'l invite .chen the brel-:e is operated.

In an el' .'ator, the combination with a car, of :in electric motor, an electroii'iagrenie brake, a honrce of current supply, an electric switch between seid source of supply nml theI motor and brake ningnet circuits, a liralrc carried liytlie car, means for apply# ingtlie car hraiie for both filirections of car travel` nml means for automatically openinc Said Lawitch when the car liralie is applied.

2S, In a traction elevator system', the com binntion el a cnr, an electromagnetic potential switch. an emergency brake carried by the cnr, mechanism for operating said brake lor both directions of car travel, a switch in the circuit of the magnet winding oli the potential switch, nml means for automatically opening said switch and ef l'ccing nn opening of the potential Switch n'lien the cnr lnnke is operated.

il), ln an elevator, the combination with a car, oi' aii ele.ctii: motor, a brake carried ln the ear, .speed controlled means for effecting: the operation of said brake, an emergency device lor operating said brake, :unl nir-:ins ois-crateri by said emergency flerice to cnt oli' the current to the motor upon the application of the einergcntry device.

QW. ln an eleiator, the combination with n car, ol a motor, a brake carried by the car, a hunil-epernhle emergency device for operntingj tlnx miel brake, and means operated by the noli-ation of the Said brake to clit off the motive power to the motor.

In te:.timon\' hei-col', l have signed my mime to thie @pccilieation in the presence of two snhscrihing witnesses.

nimeer i.. GALn, en.

Witnesses (lilas. M. Nissen', lnnw'r Il. (laan, Jr.

toi', a source of cur-

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