US487092A

US487092A - Electric switch

Info

Publication number: US487092A
Authority: US
Publication date: 1892-11-29
Anticipated expiration: 1909-11-29

Description

5 Sheets- Sheet 1. l

um EN Tm AS. NC I Jn m .JL E d. d o M 0 m No.' 487,092. PatentedNov. 29, 1892.

v J.J.NATB.

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J. J. NATE.

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No. 487,092. Patent-ed Nov.- 29, 1892.-

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UNITED STATES PATENT OFFICE.

JOHN J. ATE, OF CHICAGO, ILLINOIS.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 487,092, dated November 29, 1892.

Application filed March 29. 1892. Serial No. 426,946. (No modelt) To all whom t may concern,.- switch I have shown diagrainmatically in Be it known that I, JOHN J. NATE, a citizen Fig. '7.

of the United States, residing at Chicago, in Similar letters of reference refer to similar 55 the county of Cook and State of Illinois, have parts throughout the different views.

invented a certain new and useful Improve- The hand-rope of the elevator, as is well ment in Electric* Switches, (Case No. 1,) of known, is adapted to shift the driving-belt which the following is a full, clear, concise, from a central point, where it is running upon and exact description, reference being had to an idle pulley, to either side. On one side 6o the accompanying drawings, formingapartof the belt is carried to a pulley which drives to this specification. the apparatus in one direction, on the other My invention relates to switches and rheoside kto a pulley which reverses the motion. stats for use with elevators which are operated The arrangement of pulleys by which this is by electric motors. accomplishedis well known and maybe found 65 It has for its object the adaptation of the illustrated in the American .Mechanical Dichand-rope now in common use to the purposes tonary (Knights) under the head of Beltof switching into and out of circuit the motor shifter, page 273, and as it constitutes no eswhich operates the elevator. sential part of my invention I do not consider A further object is the provision of means it necessary to describe it further. The hand- 7o for closing the circuit through the field of rope by which the beit is shifted from one zo the motor before closing the circuit of the pulley to either of the others moves vertically armature thereof, thus saving the time which up and down or horizontally through a ceris required to charge the field-magnets. tain range and is attached to one of the levers A still further object is to facilitate the use by which the belt-shifter is actuated. 75 of beltelevators to swiftly-moving elevators. I have found it necessary in adapting an Myinvention consistsofaswitchorswitches electric motor to the service of operating a of special design, working in connection with heltdriven elevator to provide an electric a resistance-box, means for connecting same switch the different contact-points of which v to the hand-rope, and the circuits by which connect with the resistances of a rheostat and 8o this apparatus is adapted to be connected ink adjust the different positions of the lever of 3o circuit with the motor. said switch to conform to the different posi- The accompanying drawings will serve to tions which the hand-rope occupies in startillust-rate my invention. ing, stopping, or reversing the motion of the Figure l is a top view of the switch of my elevator-car. Itis obvious that when the belt 85 invention. Fig. 2 represents a detail of the is running upon the idle-pulley and when the clamp to which the cord is attached. Fig. 3 elevator is stopped or just about to be started shows an alternative device which may be the `greatest amount of resistance should be used, in which the contact-points are arranged cut in the circuit of the motor, as at that time in a straightline instead of in a segment of the least power is required and the least 9o a circle. Fig. 4 shows a switch of different amount of current consumed. It is further 4o construction for the same purpose. Fig. 5 obviousthat as the elevator is movedin either shows a sectional elevation of the switch direction the most current should be conshown in Fig. 4,viewed from line a: Fig. 6 sumedwhen the most power is required, which shows the diagram of the circuits whichI ernis when the belt driving the elevator is shifted 95 ploy in connection with the apparatus of my to one extremity or the other of its lateral eX- invention. Fig.7 showsadiagram of circuits cursion. To accomplish this harmony of rewhich I employ in connection with the appalation between the current iiowing through ratus of my invention for switching in the the motor and the work required in moving field-circuit in advance of the operating-cirthe elevator is what I design by the appararoo cuit. tus shown in Figs. l, 3, 4, 5, 6, and '7.

5o It is obvious that switches similar to those Referring to Fig. l, the cord d is attached I have shown in Figs. l and 3 may be emat each extremity to the hand-rope of the eleployed to answer the same purpose as the vator. (Not shown.) The switch-lever b, to

which is attached the cord a, is adjusted to the range of motion which the hand-rope is required to have in order to shift the belts. It will be readily understood that any motion of the hand-rope shifts the switch-lever b in one direction or the other by means ofthe engagement between the cord ct and the said switch-lever b. The cord ct is attached to the lever b by means of a clamp b,which is pivoted to the lever b. A detail of this clampis shown in Fig. 2. The lever bcarries the contact-spring h2, which makes contact with the horseshoe shaped contact piece c and also with the contact-points c', e2, &c.,as the lever is swung. The contacts c2 c3 c4, dsc., on opposite sides of the contact-plate c are connected together, so that in whichever direction the switch-lever I) is swungthe contact-spring b2 will practically make the `connection bef tween the saine circuits when moved the same distance. The contact-point c is a deadpointf-that is to say, it is not connected into circuit at all, and therefore when the contactspring b2 is upon the contactfspring c the cir-` cuit is open.

For the purpose ot' making the contact between the contactespring b2 and the contactpoints c2 c3 c", the., secure I preferably divide. the contact-spring h2, making thereof a jaw and raising the contact-points sufficiently from the base dof the switch to allow the lower member of the jaw to pass freely bef tween the base of the switch and contactf plate, as shown in Fig. 5. When the arm b2 is in the position shown in Fig. I, there is no current liowing in the circuit tothe motor, and the position of this arm corresponds to the central position of the belt-that is to say, that position in which the beltruns upon the loose pulley. As the switch-lever is moved in either direction by the motion ofthe handrope this contact-spring b2 upon the arm b engages successively with the contact-points (2 cs c4, dsc., which contact-points are connected with the resistances of a rheostat-contact c2, including all the resistances of the rheostat contact c3, a less number of resistances, and so on to the last contact-point of the series where no resistances of the rheostat is included in the circuit. I preferably make the lastl contact-plate of the series longer than the others, so as'to permit a certain amount of motion on the part of the hand-rope and therefore'of the switch-arm. NVheu the switch-arm is carried to the extreme limit, the belt will have been shifted to one or the other of the fixed pulleys and will therefore be tending to the ut, most to carry the elevator up or down, as the case may be. In either case the motor should then be receiving its full supply of current, and this is exactly what is accomplished by means of this device. Alternative forms of switches for this purpose are shown in Figs. 3, 4, and 5. In Fig. 3 instead of arranging the contactspoints c2 c3 c4 c5 c, dac., in a circular forni I arrange them longitudinally, connect ing the contactplates on each side of the cenfiancee tral dead-point c' together, the saine as in the fortnerswitch. (ShowniuFig. l.) Thecontactarm b is attached firmly to thehand-rope and slides in a groove and carries the contact spring h2 up or down by means of a cord attached to the hand-rope of the elevator. The horseshoe contact-plate of Fig. 1 appears in Fig. 3 as the long strip c, with which the contact-spring h2 makes contact. It will be readily seen that, the arm Z) occupying the position shown in Fig. 5, the circuit is open and the belt of the elevator is upon the idle-pulley. As the arm is carried in either direction the circuit is tirst.- closed through all the resistance of the rheostat,which resistance is gradually removed as the switch passes to either limit of its excursion, impelled by the handrope, until all resistance is cut out and the motor is receiving its full supply of current, at which time the elcvatonhclt will be upon one or the other of the fixed pulleys and tending;l to move the elevator up or down.

The form of switch shown in Fig. et and in section on linel x of Fig..5` is similar to the form shown in Fig. l, except that a wheel is substituted for the switch-lever, this Wheel having a grooved periphery, about which is wound the cord a, whichis att-ached at either end to the main rope of the elevator. The Africtional or other engagement between the cord aand the wheel b serves to swing the con tact-spring b2, and the operation ot' this switch will be readily understood from the descriptions already given.

I shall now proceed to describe the arrangement of circuits to which this apparatus is adapted and to show particularly an impor-` tant feature of my invention, which consists of cutting into circuit the field-magnet ofthe mot-or in advance of the main operatingcircuit.

Referring to Fig. G, which shows the rheostat, the switch, and motor diagrammatically `in connection with the circuits, e care the `two sides of the main circuit, in which the motor is located. A switch c is placedin one side of the circuit and adapted to open the same when the circuit is not in use-as, for instance, at night. The motorf, which I pre-` fer to use, is a shuntwound motor adaptedto be used with a crt-rent of constant potential. The circuits g g lead from the motor t0 the binding-posts h 7L of the switch, and thence, respectively, to the horseshoe-shaped contact.- plate c and the contact-plates cl2. As before stated, corresponding contact-points c2 ci c, dro., on opposite halves of the circular switch are connected together and in turn to the different resistance-cols fr r o" o" of the rheostat, one terminal ofthe rheostat being con nectcd to the contact-plates cl2. It results from this arangement that the movement of the arm b in either direction over the surface of the switch from the contact -point c makes contact through the contact-spring b2 betweenl contact-points c2 c3 c4, die., which are connected through the coils of the rheostat with circuit IOC g and the horseshoe contact-plate c, which is connected to the circuitg. The motoris thus cut into circuit with more or less resistance, the resistance of the rheostat being cut out as the switch-arm b passes farther and farther from the contact-plate c. The same arrangement of circuits is shown in Fig. 7, with the additional feature of a switch for opening and closing the field-circuit of the dynamo before the circuit is closed through the armature. To accomplish this purpose, the cord a, passing around the circumference of the switch-wheel b3, is joined to the main rope e2 by means of eyes 7e k, through which the cord passes freely. Knots or the equivalent thereof serve as stops at the end of the cord a to prevent the end passing through the eyes. I allow a few inches play of the cord a, making it longer than is absolutely required to pass over the surface of the circumference of the wheel h3. As a result of this there will be a certain amount of lost motion between the main rope and the wheel b3, and it is this which I make use of to operate a switch to close the circuit through the field of the motor before closing armaturecircuit. As a convenient form of such switch I may use a wheel Z, as shown in Fig. 7, around which I pass the main rope itself. This switch, however, has only the function above described-namely, to open and close the circuit through the eld, which is the circuit g', as shown in the diagram. It will be readily seen that upon any motion of the main rope after the elevator has been stopped the wheel l will be moved slightly in advance of the wheel 3,

,and any motion of the wheell will serve to close the circuit g through the contact-points m and The advantage of this construction is that it gives the field-magnets an instantls time to become charged prior to the closing of the circuit upon the motor, thus facilitating the operation of the motor.

It will be readily understood that any one of the alternative forms of switches which I have represented may be used in combination with another switch of the same kind or with another switch of any of the other modes of construction suggested to accomplish the purpose of closing the field-coil circuit before the operating circuit is closed. The dead-point c', upon which the switch-contact rests when the elevator-belt is running upon the idle-pulley, is made of considerable length to permit the closing of the field-circuit switch before the contact-spring b2 passes off from the deadpoint c. The lengthening of the open contactplate c may serve to permit the closing of the iield-magnet circuit without the addition of the lost motion between the cord a and the handle, if desired. If desired, the circuit may be left closed through the motor-field at all times, thus leaving the motor in constant readiness for operation. A further advantage of charging the field-magn et before the circuit is closed through'the armature is that it avoids thesparkingatthecommutator-brushes. The

rheostat may be placed in one case with the switch or itv may be mounted separately, as preferred. To avoid destructive effects of sparking at the points of contact between the contact-plates c2 c3 c4, dac., and the contactspring b2, I make use of carbon contact-points.

Hitherto belt driven elevators have not been adapted to use for swift passenger service because of the sudden strain to which the belts are subjected in starting the elevatorcar at the requisite speed. By the use of my device the belt may always be driven at full speed and the load put upon it as fast as the belt can carry it, or the speed of the belt and the power transmitted thereby may be gradually increased and the strain of sudden starting at f ull speed obviated.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent,'is-

. 1. The combination,with a main circuit and an electric motor, of a rheostat in circuit with the armature of said motor, said rheostat being provided with duplex contact-points arranged symmetrically upon either side of the dead-point, a contact-arm connected with the hand-rope of an elevator' and adapted to traverse said contact-points, a switch in circuit with the field of said motor and connected with said ha nd-rope, said switch being adapted to close the circuit through the field-coils of said motor before said contact-arm is moved from said dead-point, whereby as the handrope is moved in either direction circuit is closed through the field-coils in advance of the circuit through the armature and an increasing current is sent through the armature, substantially as described.

2. The combination, with the hand-rope of an elevator, of a switch adapted to close the circuit through the field-coils of an electric motor when moved in either direction, a rheostat in circuit with the armature of said motor, said rheostat being provided with duplex contact-points arranged symmetrically upon either side of a dead-point, a contact-arm adapted to traverse said contact-points and connected with said hand-rope to permit of lost motion, whereby when said hand-rope is moved in either direction the circuit through IOO the field-coils may be closed in advance of the circuit through the armature and an increasing current sent through the armature, substantially as described.

3. The combination, with the hand-rope of an elevator, of a switch adapted to close the circuit through the field-coils of an electric motor when moved in either direction, a rheostat in circuit with the armature of said motor, said rheostat being provided with duplex contact-points arranged symmetrically upon either side of a deadpoint, a contact-arm adapted to traverse said contact-points, said contact-arm being connected with a rope passing by its ends through eyes attached to said hand-rope, said rope being provided with enlargements upon its ends, said enlargements when said rope is drawn taut being ata greater distance apart than are said eyes, so that the rope passing through said eyes may not partake of the motion of the hand-rope until it shall have moved through a certain distance, 1 whereby circuit may be closed through the field-coils in advance of the armature and an i increasing current sent through the armature,

substantially as described.

et. The combination, with the hand-rope of an elevator, of a switch attached to a Wheel,

eithers-ide of adead-poin15,9l contact-arm adapt-` ed to trave rsesaid con tact-points and attached to a wheel encircled by a rope passing by its ends through eyes carried upon ysaid handrope, said ends being provided with enlarge- .ments which when pulled taut are a greater distance apart than are said eyes, whereby when `said handel-ope is moved in either direction circuit will be closed through the fieldcoils in advance of the armature and an increasing current .sent through the armature, substantially as described.

In witness whereof I hereunto subscribe my name this 19th day otMarch, A. D. 1892.

JOHN J. NATE. Witnesses:

GEGRGE McMAHoN, GEORGE L. CRAGG.