US1114813A - Safety-switch. - Google Patents

Description

H. B. SHREVB.

SAFETY SWITCH.

APPLICATION FILED JAN.11, 1912 1,114,813, I Patented 0015.21", 1914.

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Be it known thatI, HARRY B. Smmvn, a citizen of the' United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new' and useful Improvements in SafetyfSWitches; and I do hereby declare that the following is a lfull, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters Iof reference marked thereon, which lform a part-of this specilication.

This invention relates to certain novel improvements in electric safety switches'more particularly intended for 'use in connection with elevator systems, movement of the elevatoi'when any of the doors or gates opening. into the elevatorshaft are opened or stand in open position.

The general featuresof thistype of switch are familiar and include a switchmechaiixed in the elevator-shaft and a member carried by the door or gate, .the switch mechanism heilig so arranged that the electric circuit controlled by the switch is broken whenever thev door or gate is opened and remains thus until the door or gate has been moved into closed and locked position, the member carried by the door engaging and operating' a movable member of the switch to close the circuit. The electric circuit controlled by the switch embraces the motorl which operates the elevator and also-a brake-mechanism which is normally inoperative as long as the electric circuit is closed.

The invention consists of the novel teatures of the switch as hereinafter described and more particularly pointed out inthe appended claims.

f In the drawings r-Figure 1 is a front elevation of Jthe improved switch mechanism with the front cover of the casing that in- 'y closes the switch mechanism removed, and

with the parts of the 'switch shown in position as when the circuit is open. Fig. i! is a similar view showing the parts in position as when the circuit is closed. Fig. is a View like Fig. 2-showin the parts of the switch in closed position ut with the members which operate it at ainal limit of 'their l Fig. 4 is a, view representing a through the switch in a l Fig. 5, Fig. 5. is va cross-section tbnnuglr- --the switch movement. .vertical section to stop or'prevent- Specification of Letters Patent. i Application inea new@ 111918. sensi nu. 741,412.

plate` 18` which is of Ufform Y rammed' oct. 27, 19111.

plane .indicated by. the line- 5,'-5 of Fig. v

Referring now to-that embodiment of my invention illustrated in the' drawings, 10'v1n. dicates a casing orhousing that incloses the switchmechanlsm and is adapted-.to be at-- tached tothe wall of the elevatorshaft'in 'a positionin alinement with a switch .operatf ing bar or arm 11 carried by the movable,v

door or gate. Thesev are so arranged relaf tively to eachother, that when. the dooris moved to closed position, the arm lllwill .operate the switch toelose the circuit.- l.

12 indicates'a blockof insulatingmaterial which extendstransversely ofthe-casing 10- and is rigidly connected to the-bottom wall 10a of-saidl casing in any suitabl manne'r.

On the front edge of said block 12-(the leftf l hand edge as shown '1n the drawings,)` are fixed ,two contact. members 13, 13 whichare `spaced apart and constitute terminals ,ofi the electric circuit of the elevator systemwSaid contact members .as shown are parts ofi dat bars 13, 13.*, which, having their endsbent 1' downwardlyand engaged against the iront.'

edge of said block, arey attached. by suitable screws to the top of the block, and have their other end parts bent. downwardly andl om' gaged against the rear edgeof saidblock and then odset parallel tothe bottom wall of the box 4and spaced therefrom to provide supports for binding posts 14, 14 by means-- of, which they areconnected with the conductor wires 15, 15 of the electric system. Said bars 13, 13, are so-dimensioned-and spaced part and the block 12 itself is lmade ofsuch' thickness that a.- snitable air space or gap for insulation purposes-is providedsbetween said bars and the bottomwall, side walls and cover .plate of the box.

16 indicates al vmovable insulationnbfoclr arranged to slide on the bottom wall or lie casing which. is preferably -provided with )arallel spaced bearing ribsl rising thereromr and. extending box. j

17, 17 indicate contact members fixed on the rear edge ofthe block 16 inline with the fixed contact members '13 13 and ad for. contact-'therewith v block i6 is moved toward the fixed block -12 longitudinally.v yof thel 'tor-that purpose. Said contact members 17,

as shown in thdrawi'ngs, form part 'foi a th the .legs

'ofv the fU-g bent dowmvardlyl against the rear.'

w en the movable apted edge o1' the block 16 and the transverse. member of the Ul engaged against and at` tached by suitable screws to the top face of,

said block. In this case, as in the case of the fixed contact members, the metal U-platev Y roviding the contact members 17, 17 and the movable block 16 itself areso proportioned and dimensioned with reference to the bottom and side walls of the casing and' the cover-plate thereof that an efficient air-A gap is provided for the purpose of insulating the contact members 17 17 and the part .of the plate connecting them from the -metallic walls of the casing.

The movable insulation block 16 is mounted on 'a-reciproc'able plunger-rod 1 9vvhich is located midway between the two Contact members 17, 17. Said plunger-rod has reciprocatory bearing at its rear end in a sleeve 20 secured in a suitable aperture or recess opening through the front edge of the fixed insulation block 12. vThe Jforward end of the plunger-rod is, as shown, made integral with a buffer-block 21 that projects through and has' bearing in an opening formed in the front side vva.ll.10c of the casinv. Said butter-block has laterally extend# y ing shoulders 22 at its rear end which are adapted for engagement against the inner surface ofthe said front side wall 10 and -act to limit the outward movement of the plunger. The buffer-block 21 is in line with the movable arm 11 carried by the door or gate of the elevator-shaft and is adapted to l)be struck thereby when said door or gate is moved to closed position. y

The plunger rod 19 extends through and has bearing in a sleeve 23 fixed in a suitable aperture in the movable insulation block 16. Said sleeve is made slightly larger in intei-nal diameter than the diameter of the plunger-rod so as to provide a loose'bearing for said rod. This permits a loose lay of the movable switch member on .the p unger` rod adapting it to swing into a position at a" osition at right slight angle to its normal for a purpose angles to said plunger-ro presently to be explained.

The sleeve 23 has at its front end an inwardly extending flange 23 which forms-a seat for coiled springs 24 and 25 mounted on the plunger-1od,-the first, namely, the spring 24 being placed on said rod at the .rear of said angenand the second, namely, 'the spring 25 bein'g placed on 'said rod 1n front of said flange. The rear end of the 'spring 24 enga. es against the fixed insulin tion block 12 w ile the forward end of the spring 25 engages against the rear end of the buffer-block 21. The latter spring is heavier .than and is not so easily compressible as the spring 24, the purpose of which difference will nowaappear.

The operation of my improved switching mechanism is as follows: The wpartg-normall standin the relative-'positions indicate in'Fig. 1 when the door or.- gate is .in

I open position; In this position the movablecorita'cts 17 are separated from the ixed'contacts 13 and vthe -electric circuit open.

the door moves ytoward closed position the arm 11, just before the door or gate reaches wit out compressing the'spring 25 and bef fore the buier-block 21 an the plunger-rod 19 has reached the full .limit of its inward movement. A further movement of said buffer-block and plunger-rod will be'. permittedby. reason ofthe compressibility of the spring 25 which comes into action after. the contactual relation of the fixed and-sinovable y'contact members 'has been' broughtzirv about. Thus some variation '-in the finalpo.-

sition of the armll carried bythe 'door-vor.

gate ispermissible without danger of'lailure of the operation of the On account' ofthe flexibility of the movable insulation blockv 16 onthe'plungerfrod 19 and its capabilityof assuming a position at an angle to its right angular position on said rod, the proper closing of the switch is insured in case by reason of arcing or'otherwise between the opposing contact members'- a lug or excrecence 1s formed'on one or the other s o that one vpair of opposing contact `members are brought into engagement be- ,scfo're the other.

the two opposing contact members, one.o f

Under these circumstances which carries lthe said lug or excreccnce will engage' first before the plunger-rod has reached.- its linal position, and the othericontact` member of the movable switch member will becarried forward notwithstanding thel stoppage referred to until it is brought into engagement with its associated fixed "com tact member, the parts assuming suchtion as indicated in dotted lines in Fig.12'.f

I claim as my invention y parts -as described.

1. A switch device of the kinddescribed` comprising theV combination of a casing, of a fixed insulation block secured within said casing, laterally spaced contacts carried by.

said block, a movable insulation block in.

said casing, laterally spaced contacts carriedA thereby each in line with and adapted for contact with one of the rst named contapts, a reciprocable plunger in said casin '1 on which said movable insulation s loosely mounted, a buer 'fixed on said plunger projecting without said casing and provided with stops to limit its outward movement, a spring'interposed between said movable insulation biock and said fixed insulation block, and a more rigid. spring interposed between said buiier block and said movable insulation block.

2. AV switch device of the kind described comprising the combination of a casing, of a fixed insulation block secured within said casing, laterally spaced contacts carried by said block, a movable `insulation block in said casing, laterally spaced contacts carried thereby each in line with and adapted `for contact with one of the first named contacts,

a reciprocable plunger in said casinor on which said movable insulation blocc vis loosely mounted, said plunger bein provided with a buierat one end whic vprojects without said casing, means for limit ing the outward movement of said plunger,

and yielding means acting to resist movementl'of the mova'ble insulation block in either direction on said 3. A switch device o comprising the combination of a casing, of a fixed insulation block secured within said the kind described casing, laterally aced contacts carried by said block, a Inova le insulation block in said casing, laterally spaced contacts carried thereby each in line with and' adapted for contact with one of the rst named contacts, a reciprocable plunger in said casingl on which said movable insulation bloc is mounted, said plunger being providedwith a buffer at onev end which pro Y 'ects without said casing, means for limiting the outward movement of said plunger, ielding means interposed between said two -'insulation blocks acting to resist the movement of one toward the other, and yielding means interposed between said movable block and a fixed part of said plunger actto resist movement of said block toward the buffer end of said plunger, being capable of eater resisting the first named yielding means.

In testimony that I claim the foregoing as my invention I aiYiX my signaturev in the presence of two witnesses, this 30th day of December., A.. D. 1912.

HARRY B.- SHREVE..

ing

force than .Witnessesz GEORGE R. WiLniNs, T. H. ALiiznDs.

the latter

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