US2932365A - Testing apparatus for safety mechanism for doors - Google Patents

Description

April 12, 1960 S. A. HORNUNG TESTING APPARATUS FOR SAFETY MECHANISM FOR DOORS Filed July 19. 1957 "I" @NFI ww.

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Br l ATTORNEY April 12, 1960 s. A. HORNUNG 2,932,365

TESTING APPARATUS FOR SAFETY MECHANISM FOR DooRs Filed July 19, 1957 2 Sheets-Shea?I 2 w y r M mw :A 6 mrlfAAis m m M- Tel I l l IIRK 4 J M I I I IIAH=T||EX d. Vn w H|||I|||||||E\ G. lllllllll J 6 MM -IHA f/,ll -J f M @11:11: WIIIIL? F m A I l l I l :Af lllllllr H Bz um TESTING -APPARATUS FOR SAFETY MECHA- NISM FOR DOORS Stephen Anthony Hornung, NewYork, N.Y., assignor to Otis Elevator Company, New York, NX., a corporation of New Jersey Application July 19, 1957, Serial No. V672,928 9 claims. (ci; 187,548)

The invention relates to a` device for monitoring safety mechanism, such as'safety mechanism for protecting againstv closing doors of elevator installations. It' is commonpractice in present day passenger elevator installations, where the closing of the'doors is etected automatically, to provide safety mechanism to avoid striking a transferring passenger with a clos-ing door. Automatically controlled doors provided with' safety mechanism may be closed at speeds faster than would otherwise be practical, which is desirable from a service viewpoint. However, if this safety mechanism` becomes inoperative there is the likelihood that a transferring passenger may be struck with considerable force by a closing door.

If the operation of the safety mechanism given priority over elevator'operation, when a safety mechanism failure occurs, the doors'may be retained in open position. This results in the car remaining inoperativeat a oor. As an alternative, the doors may be closed at a slower speed after' they have remainedfopen an .abnormally long time. However, in automatically controlled elevators if the failure s of an intermittent nature it may not be brought to the attention of service personnel Yfor s ome time. When notice of the poor elevator response is obtained, much time may be spent before the .cause is found to be inoperative safety mechanism. AThis .results in reduced elevator efficiency.Y

The prompt reporting of the inoperativeness or lack .of sensitivity ofthe safety mechanism allows the door to be closed at reduced speed at the expiration of normal .door open time. and pinpoints .the source'of the trouble immediately'. Also, ya test of the sensitivity of the safety FCC.

alarm is initiated and the speed of the doors in closing is reduced below normal closing speed. In carrying out the invention, according to the arrangement which will'be described, the safety mechanism'is stimulated a predetermined minimum amount to approxi.-l

, mate the effect on the safety mechanism of a persorrorv object in the path of movement of the doors in'closingl Features and advantages of the invention will be seen` from the above and from the following description of operation when considered in' conjunction with the draw# ings in which: l

Figurel is an "across-the-line simplified wiring diagram of a portion of elevator power and vcontrolcircuits;` 'Figure 2 is an across-the-line vsimplified wiring dia-` gram of one form of door protective mechanism which' together with the control circuits of Figure 1 embodies the" invention;

' Figures 3, 4 and 5 are across-the-line simplified wiring diagrams for other forms of door protective mechanism to which the invention is applicable; and,

Figures 1s, 2s, 3sA and 4s are spindle sheets for use in side-by-side'alignment with Figures l, 2, 3 and 4 respec-y tively, for locating the coils and contacts of these circuits. In View of the simple circuit involved, no spindle sheet is shown for the wiring diagram of Figure 5.

` For convenience, the invention will be described as I applied to the safety mechanism of the patent toW. H.

.mechanism before it is required to function minimizes 'the danger of injury'to passengers and makes practical :the use of preventive maintenance. All other factors remaining equal, this results in less costlymaintenance `and more efficient elevator service. It is, therefore, an object of the invention to provide .fa device which detects and reports .the -inoperativeness or faulty operation of elevator door safety mechanism. Another object of the invention is to provide a device :which will test the operation -of the safety mechanism .at a predetermined level of sensitivity before the safety mechanism is required to function.A l

Another object of the invention is to provide a device which will reduce the speed of vthe doors in closing ybelow the -normal closing speed, whenever the safety mechanism is detected as being inoperative or insensitive. A further object of the `invention is to maintain an alarm indication and the reduced door closing speed fonce they are initiated, until the car departs from that iloor at which the inoperativeness of the safety mechanism was detected, even though the safety mechanism :again become operative. Y

The invention involves a device to cause false operation of the'safety mechanism in order to test its effectivemess. Ifthe. safety mechanism fails to false operate, an i' Bruns et al., No. 2,634,828, granted April 14, 1953, with particular reference to the circuits of Figure 4. The electromagnetic switches employed'in the circuits v shown in Figures l through 5 are designated as follows;

B-Safety mechanism switch DC-Door close switch y DE-Door speed switch DO-Door open switch DP--Door protective relay DFX- Auxiliary door protective relayv vDR-Door control switch FR- Flicker relay MR-,Monitoring relay NT-Hall time switch KNT-Auxiliary hall time relay Throughout the description which follows, these letters willbe applied to the coils of the above designated switches and, with Vreference tonumerals appended thereto,to the contacts of these switches. The electromagnetic switches are illustrated in deenergized condition. Door control switch DR is a latching type switch and is illustrated in reset condition.

Referring iirst to Figure 1, the door power and control circuits are connected to direct current supply lines designated W+ and W-. Car running relay FE (not shown) is energized incident to starting the car and is deenergized incident to stopping the car. Door relay GHI (not shown) is energized incident to opening the door and remains energized until the door is in fully closed position. Field and brake switch H not shown) is energized incident to starting the car and is deenergized when the car is stopped. l

Clar position-indicator lamps LPl and LPS are provided, one for each'iloor served by the car and may be located ina panel at the building lobby. The alarm buzzer is designated BZ and may also be located at the lobby. Contacts CLI to CL3 and CB1 to CBS are provided, one CL contact and one CB contact for each oor served by the car. Brushes b1 and b2 engage the CL and CB contacts, respectively, in accordance with car movement 'to prepare the car position indicator lamp LPand buzzer BZ circuits Yfor the floor at which the car is to stop.

Doorfopen lim-it switch DOL, door close limit switch DCL and door speed limit switch DEL are actuated by Patented Apr. 12. 1960.

door movement and are illustrated for the closed position of the door.

Referring to Figure 2, the door protective circuits are connected to a source of singlephase alternating current represented by wires W11 and W12. SGT- and DPDT are constant voltage transformers for providing the desired value of alternating current voltage. The car door sight guard CSG and the car door strike jamb post guard CPGV are connected to the ungrounded side of the secondary winding of transformer DPDT, thus shielding the tubes from unwanted operation due to ground potential. The hoistway door sightgu'ardsHSG and the hoistway door strike jarnb post A are connected to the ungrounded side of the secondary winding of transformer SGT, thus shielding the doors against unwanted operation as they near closed positions. For simpliity,the hoistway door post guardsHPG and sight guards HSG are shown for only one licor in the building.

Also for simplicity, the circuit for one protective tube DPT and its associated apparatus is shown instead of the three protective tubes DPTl and DPTS and their respective associated apparatus shown and described in connection with Figure 4 of the BrunsgPatent No. 2,634,- 828. An adjustable point on voltage divider resistor RVD for the tube is connected by way of current limiting resistor RIB to the control electrode DPTE and conductive spot CS of the tube. The antenna CA for the tube also is connected to the control electrode DPTE and conductive spot CS. Direct current is provided through rectifier EDP for the anode-cathode circuits of the tube, approximately 150 volts being obtained with 120 R.M.S. volts from the transformer secondary winding which is insulicient in itself to cause a breakdown of the tube. A iilter network is provided by condensers QF1 and QF2 and resistor RF. To prevent any undesirable effect on the tube by action of stray fields, shielded conductors are employed with the shields connected to ground as indicated at points SGR. The Vtube is fired by eifecting an increase in antenna to ground capacity by the body capacity to ground of a person in the zone of inuence of the antenna. The physical construction of the protective mechanism is more fully illustrated and described in the aforementioned Bruns Patent No.

The manner in which the doors are controlled may vary considerably. In the particular circuits illustrated in Figure 1, the doors open automatically as a stop is made at a landing and close automatically upon the expiration of a given time interval. Auxiliary hall time relay XNT and hall time switch NT are both operated during the running of the car. As the car arrives at the landing at which the stop is being made, field and brake switch H deenergizes. Contacts H1 separate to disconnect the coil of auxiliary hall time relay XNT from the supply lines. The deenergization of this relay is delayed by the discharge of condenser QXNT. Contacts H2 close to complete a circuit by way of contacts XNT2 for the set coil of door control switch DR. Switch DR latches itself in operated condition. Contacts DRZ close to complete a circuit by way of door open limit switch DOL for the coil of door open switch DO. Contacts DOS and D06 close and contacts D04 open to establish a circuit for the armature DMA of the door operating motor through resistors RDMZ and RDM3 to open the car door and also the hoistway door. As the doors move a certain distance, door speed limit switch DEL closes to complete a circuit for the coil of door speed switch DE. ContactsDES and DES engage to short circuit resistance RDMF in circuit with door moguards HPG tor field winding DMF and resistance RDMS in circuit with armature DMA, respectively. As the doors near open position, door speed limit switch DEL opens and door close'limit switch DCL closes without eiect, As the doors reach open position, door open limit switch DOL opens to deenergize door open switch DO to break the circuit for armature DMA. Contacts D01 separate to deenergize door speed switch DE. Contacts DB4 engage to establish a short circuit for armature DMA to bring the door operating motor to a stop.

Upon the expiration of a given time interval, auxiliary hall time relay XNT is deenergized. Contacts XNT3 separate to disconnect theVV coil of hall time switch NT from the supply lines. Switch NT does not deenergize immediately, being delayed by the discharge of condenser QNT. Contacts NT2 close to establish a circuit by way of contactsfDRl for the reset coil of door control switch DR which is restored to unlatched condition. Contacts NT2 also complete a circuit by way of door close limit switch DCL and contacts DPI and D02 for the coil of door close switch lDC to initiate the door 'closing operation. A time interval is thus provided, namely the interval of relay XNT, Say three seconds, plus the interval of switch NT, say another three seconds, or a total of six seconds, from the time that the stop is made before the closing of the doors is initiated. This time interval is deiined as the door dwell period." Door close switch DC upon operation engages contacts DCZ and DC4 and separates contacts DC3 to complete a circuitfor armature DMA to clos'e the car door and hoistway door. As the doors move from fully open position, limits'witch DOL recloses 'without effect at this time. During the closing operation, limit switch DEL is again closed, causing operation of door speed switch DE. Contacts DES close to shortY circuit motor field resistance RDMF and contacts DB6 open to remove a short circuit for a portion of resistor RDMS. Asthe doors reach closed position, door close limit switch DCL opens, breaking the circuit for the coil of door close switch DC. Contacts DCZ and DC4 open to break the circuit for the door motor armature DMA. Contacts DCI and switch DEL open to deenergize switch DE. Contacts DB4 reengage to establish a Short circuitV for armature DMA to bring the door operating motor to a stop.

The protective circuits of Figure 2 are effective only while the car is stopped due tothe provision of contacts H3. Referring tothe circuits for tube DPT, there isa capacity network from antenna CA tov shield CSG and Ifrom antenna CA to ground. Thus a biasing voltage is applied to both the control electrode DPTE and the conductive spot CS adjacent the anode, which bias is due to a direct current potential taken from resistors RVDA, RVD and RVDB, andan alternating current potential which is a function of the ratio of the two capacity networks. This is adjusted 'so that the biasing voltage is just below tube breakdown value. Resistor RIB lis of such value as to effectively isolate the alternating current source from the direct current source. When a person enters or leaves the Ycar his body capacity ineiect increases the antenna to ground capacity and thus brings the potential of the conductive spot and control electrode -toA which itl is connected nearer to ground potential. When during the closing of the doors antenna CA comes within a predetermined distance of a person, the alternating current potential reaches a `value which causes breakdown of tube DPT. This 'completes the anode- 'cathode circuit of the tube which extends through the coil of door protective relay DP, causing thisV relay to operate. Upon operation, door protective relay DP causes the door to stop and then reopen as more fully described in connection with Figure 4 of the Bruns Patent No. 2,634,828.

`In'order to minimize the chances of a person being hit by a closing door and to obtain an indication'of the failure of the protective mechanism, the protective mechanism may be tested by causing tube DPT to conduct as if a person was detected in the path of the door.

.False operation of the protective mechanism toY test it may be caused by removing `the shield voltage applied to any' of the following: hoistwa'y-doorsight guard' HSG," ,a

post guard HPG, car door sight guard CSG, -and post guard CPG, or by increasing the biasing voltage appliedy to conductive spot CS and electrode DPTE.

In the preferred to lire is applied to the hoistway door sight guard HSG by closed contacts MRS which connect-the sight guard to a top on transformer SGT. This reduced shield potential on the hoistway door sight guard HSG has no etect ou the protective mechanism at this time since brake contacts H3 are open while the car is running, as previously mentioned. l

Incident to the car stopping at a floor, car running contacts FE1 open but are not effective at this time, being bypassed by the self-holding circuits MR1 through DPXI and GHI. As the car stops at the floor, contacts H3 close to render the protective mechanism effective. As the doors begin to open, door relay contacts GHI open without affecting monitoring relay MR. The aforementioned reduced shield potential applied to, HSG via the transformer SGT tap brings the antenna closer to ground and causes the tube to conduct energizing door protective relay DP. Contacts DPS close to energize auxiliary door protective relay DPX which is delayed inv dropping out through contacts DPX4.

Contacts DPXI open to breakthe self-holding circuit of monitoring relay MR thereby rendering any subsequent actuation of contacts DPXI, GHI or XNT1 ineffective. Contacts MR4 close and contacts MRS open to apply full shield potential to sight guard HSG, thereby removing the stimulant to false operation of the protective mechanism.

As the doorsbegin toppen, if the protective mechanism Ifails to operate under the stimulation of reduced shield potential which approximates the eiect on the mechaf nism of the presence of a personin the path of the closing` door, monitoring relay MR remainsenergized through self-holding circuit MRI, DPXI. Closed contacts. M R3 short circuit part of 'resistor RDM4 ina parallel with' door motor armatureDMA'to reduce the speed vof the,V door closing.l At the expiration of the time interval of auxiliary hall time relay XNT, contacts XNT1 close to maintain relay MR energized, even though during the door closing operation, tube DPT may conduct and cause contacts DPXI to separate. At the end of the door dwell period contacts NT1 close to complete the circuit to energize flicker relay FR through closed contacts MR2. Flicker relay contacts FRI and FR?. close and open to flicker the lamp LP, corresponding to the floor at which the car is stopped and to-ring buzzer BZ as an indication of the faulty operation of the protective mechanism. The alarm condition and reduced door closingspeed, once initiated, is maintained until contacts NT1 separate to break the circuit to ilicker relay FR as the car leaves the floor.

Arrangements for monitoring the operation of other forms of door -protective mechanism may be employed. To illustrate this, examples of other forms of door protective mechanism are illustrated in Figures 3 and 4. These circuits are arranged to be used with the door oper# ating circuits shown in Figure l below relay MR.'

Referring to Figure 3, the circuits there illustrated are for-the light ray type of protective mechanism suit# able for both sideopening and'ce'nter opening doors.

vembodiment of the invention, the shield voltage applied to the hoistway door sight guardv PHTI 'fand- 'PHTZ `'are indicative fof4 a plurality ofl photo tubes', such asth'e 918 type, positioned' on oneside vof the car door entrance to scan an area of average person height'. Llvand'LZ are pinpoint sources of light for the photo'tubesarranged onA the opposite side of the entrance in linerespectively with the photo tubes for which l they are provided. The photo tubes are arranged to act through an amplifying tube AMT having its control gridY connected to the point X. This tube may be a pen'tode such as 6SJ7 to provide a high gain. The coil of safety mechanism switch B is in the anode-cathode circuit of tube AMT. So long as the light ray for each tube PHT is not obstructed, a positive potential exists at point X to cause sutiicient current flow through tube AMT to' operate safety mechanism switch B. Thus contactsv B2 are separated. Contacts H4 close-when the ca'r-V stops at `ai licor `and lremain closed -until the car kdeparts from that liioor. Upon' obstruction of one or more ofthe light rays by-passenger transfer, the potential at point X is reduced sufficiently to cause the deenergization of 4safety mechanism switch B. Contacts B2 engage to cause operation of door protective relay DP which in turn engages con` tacts'DP4 to cause operation of auxiliary door protective relay DPX. Relays DP and DPX control the doory operating circuits of Figure l to prevent the then closing of the door or'if closing, to return it to open position as described in Brunsv Patent No. 2,634,828. Also, if any of the light sources or photo cells are inoperative or tube AMT fails to conduct properly, contacts B2 engage to open the doors. In this case the doorswill remain open after the door'dwell period has expired.

Referring now to Figures 1 and 3, while the car is running, monitoring relay MR is energized through car running contacts FE1. Closed contacts MR6 insert the full value of resistor R1 in series with light sources L1 and L2. The excitation for the light sources L1 and L2 is reduced to a value which will bias tube AMT to conduct less current than the minimum current requiredl tol maintain switch B energized. The sensitivity of the photo tubes PHTI and PHTZ is testedin this manner. Therefore, switch B is in deenergized condition while the car is running. Contacts B2 are not effective at this time since the circuits of relays DP and DPX are inoperative auxiliary hall time relay XNT, as previously mentioned.-

When the car slows fdown, contacts FE1 open'without aifecting relay MR due to self-holding circuit MRI, GHI.l As the doors begin to open prior to the car coming to a stop, contacts GHI separate breaking the circuit of relay MR through self-holding contacts MRI. 1 Contacts 'MR open and contacts'MR7 close to-short circuit part of re-l sistor R1 to apply full voltage to light sources L1 and L2. The bias of tube AMT is reduced causing it to conduct and energize switch B. As the car stops, contacts H4 close putting the door protective mechanism into opera-Y tion. Contacts B1 close without effect since contacts MRI are already open. y' I As the doors begin to open, although the excitation of the light sources L1 and L2 isreduced, as previously de# scribed, the protective mechanism may fail to' false operate. This failure may be due to tube AMT continuing to conduct, relay B failing to deenergizeor contacts`B2 being stuclt together. Whatever the reason for the failure may be, if contacts VB1 are closed, as contacts FE1 open and contatcs GHI separate incident to the car slowdown and the door opening, relay vMR remains energized. At the expiration of the time interval of auxiliary hall time relay XNT, contacts XNT1 close to maintain relay MRene'rgized. `At the expiration of the door dwell period, the door closes at reduced speed and an audible and visual alarm is initiated, as previous-r ly described.v r'Without this described pretest of the protective mechanism,y if. during closing movement of the door-the light beam is` interrupted, with contacts B2 stuck 7 together, the door will continue to close at full normal doorV 'closing speed with the protective `mechanism inoperative. Y f

Referring to Figure 4, the door protective `circuits therein lustrated are based on the circuits of Figure of the patent to Lubkin No. 1,982,442 granted November 27,

contacts GHl separate incident to c arj slowdown and door opening, relay MR remains energized. Contacts XNTI 1934. A capacitor Q50 made up of trough TRSI and plate PLS'S extends vertically over a scanning area along the front edge of the car door. Q62 is a shielded compensating condenser variable in accordance with the position of the doors forv preventing unwanted operations. Connections to one side of capacitor Q50 andcondenser Q62 are led through shielded cables to box B061. This box, the shield for condenser Q62, the cable sheaths, the other side of condenser Q62 and capacitor Q50 are connected to ground. Within box B061 is a triode vacuum tube OST86 with its grid and anode connected to a tuned circuit made up of` condenser Q88 and inductance 1N87, this being utilized to generate high frequency oscillations. RET96 is a triode vacuum tube with its input circuit conducted across inductance I l104. The coil of switch B is connected in the anode-cathode circuit of tube RET96. Inductances IN87 and IN104 are inductively coupled so that the generated high frequency oscillations are induced in inductance INI04. In parallel with inductance INI04 are capacitors Q50 and Q62 to form in conjunction with condenser QI13 a tuned circuit TC112. Condenser Q116 in parallel with condenser Q50 is prevented from affecting tuned circuit TC112 during normal operation of the door protective mechanism by open contacts MRS, whose operation will be explained later. With no person in the entranceway the tuned circuit is in resonance with the generated high frequency oscillations causing sufficient current flow in the coil of switch B to maintain this switch in operated condition. When a person or object in the entranceway alters the electrostatic eld due to capacitor Q50 and thus detunes the tuned circuit TC112 from resonance with the generated oscillations, the current flow is reduced sufficiently to cause switch B to deenergize and complete the circuit for the coil of relay DP. As previously explained, this relay controls the door operating circuits to prevent the then closing of the door or if closing, to return it to open position.

Referring to Figures l and 4, while the car is running, monitoring relay MR is energized through car running contacts FEI and is maintained energized through selfholding circuit MRI, GHI. Closed contacts MRS conneet condenser Q1\16 in parallel with condenser Q50 of tuned circuit TC112. Condenser Q116 has a value of capacity selected to approximate the effect of the body capacity of a person in the path of a closing door at a predetermined distance from the front edge of that car door on capacitor Q50. This selected value of capacity is sucient to detune the tuned circuit TC112 from resonance with the generated oscillations. Thus, current ow is reduced suiciently to cause switch B to deenergize. The operation of the protective mechanism is tested at a predetermined level of sensitivity -in this manner. Contacts B1 are not effective at this time since the circuits of relays DP and DPX are inoperative due to open contacts H4. When the car slows down, contacts FE1 open without `affecting relay MR. As the doors begin to open prior to the car coming to a stop, contacts GHI separate breaking the circuit relay MR through self-holding contacts MRI. Contacts MRS open removing condenser Q116 from thecircuit of T0112, returning that circuit to resonance with the generated oscillations to cause sufficient currentto ow in the plate circuit of tube RET96 to energize switch B. As the car stops, contacts H4 close putting the door protective mechanism into operation. Contacts B2 close without effect since contacts MRI are already open. With condenser Q116 disconnected, as previously described, if contacts B2 remain closed to indicate a failure of the protective mechanism, .as contacts FE1 open and 7.5

close ,at the expiration of the auxiliary hall time relay time interval. Relay MR controls the door operating circuits ,to reduce the closing speed of the door and initiate an alarm indication, which once initiated is maintained by closed contacts XNTI, as previously explained.

p Anarrangement for monitoring the operation of still another form of door protective mechanism is illustrated in Figure 5. This circuit is arranged to be used with the door operating circuits shown inFigure 1, wherein all contacts designated DPX are to be considered contacts designated DP. The circuits of Figure 5, with the exception of monitoring antenna MA are the subject matter of the yco-pending application of Lew H. Diamond, etal., Serial No. 697,370, iied November 19, 1957. TRBI and TRBZ designate transformers. AMI to AM3 designate amplifiers. VDI and VD2 designate voltage doublers. PI and P2 designate potentiometers. An alternating voltage source is connected from line BO to ground G, this source being indicated hy block OSC. The anodcs of amplifier tubes AT1, ATZ are connected to supply line B+. Current for the coil of relay DP is provided from alternating current supply lines AC1, ACZ. The four antennae UA1, UA2, LAI and LA2 form capacitances to ground. They are arranged in pairs and are positioned one above the other along the leading edge of the car door.

The antennae of each pair are connected directly to the opposite side of the diagonal of a bridge, with each antenna connected in a different bridge circuit from the one in which is connected the next succeeding antenna. Each bridge is adjusted to provide substantially zero voltage across its diagonal w'nen no object, such as a person, sought to be protected, is in the field of inuence of the antennae connected lin that bridge. When such person comes into the ield of influence of one or more antennae, there is sufi'lcient change in capacity in one leg with respect to the other of one or more bridges to cause a suicient signal voltage to appear across the diagonal of the bridge, which when ampliiied energizes relay DP. Relay DP in turn is caused to operate mechanism to bring the door to a stop if closing or to prevent its closing if it is in open position.

Monitoring antenna MA is provided to span the two centrally located antennae UA2 and LAI, and is rendered effective during each initial door opening operation to cause sufficient decrease in impedance of one antenna of each bridge to ground to cause operation of relay DP. By means of door limit switches DLI and DL2, the monitoring antenna is connected to line BO while the doors are in closed position and in open position and during door closing, thereby rendering the monitoring antenna ineffective to cause operation of relay DP during this time. Monitoring antenna MA is connected to line BO by shielded cable, with the shield, not shown, connected to ground. During the initial door opening operation, when the car stops at a oor, these limit switches disconnect the monitoring antenna from line BO, enabling the antenna by means ofthe capacitance coupling to ground of its wire in the grounded cable to bring ground potential sufficiently near the center antennae UA2 and LAI to cause operation of relay DP.

Limit switch DLI is a toggle switch which opens when the door reaches approximately one-quarter inch of closed position and remains open until the door reaches approxi- 'mately one-quarter inch of open position, at which point it closes and remains closed until the door again reaches, roughly, one-quarter inch of closed position. Limit switch DL2 is set to open at approximately one-half inch of door opening movement and close as the door arrives approximately within one-half inch of fully open position.

When the door starts to open ata floor at which a stop is being made, limit switch DL2 opens, disconnecting monitoring antenna'MA ,from line BO. Assume that the detecting mechanismis'functioning properly, Vthis causes operation of relay DP to open contacts DPXI (Figure l)l opening operation, relay MR remains energized to close the door at slow speed and initiate an alarm as-previously explained, advisingthat the detecting mechanism is not functioning properly. 1 v Asmany changes could be made in the above construction and many apparently Widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrated and not in a limiting sense.

What is claimed is: 1. In a control for opening and closing an elevator door, door actuating means for moving said door in an opening direction at a given speed and for closing s aid door at either of two predetermined speeds, protective mechanism responsive to the presence of an object in the path of the door duringV its closing movement and effective to control further movement of said door, testing means normally adapted to actuate said protective mecha-` nism momentarily to its operated condition during the opening of said door, and control means operatively responsive to the operationof said protective mechanism in responsevto said testingmeans for causing said door actuating means to close said door at the slower of said two predetermined speeds under conditions where said protective mechanism fails to operate in response to said testing means and to close said door at the other of said speeds under conditions where said protective mechanism operates in response to said testing means.

2. In a control for an elevator door in which power actuated mechanism moves said door in its opening and closing movement, said closing movement being in accordance with either of two predetermined modes of operation, protective mechanism mounted on said door responsive to the presence of an object in the closing path of the door and effective to control subsequent movement of said door, testing means operative during the opening movement of said door for subjecting said protective mechanism to controlled conditions designed to cause its actuation, and control means operatively responsive to the reaction of said protective mechanism to said controlled test conditions andetfective to cause said power actuated mechanism to close said door in accordance with one of said two predetermined modes of operation and effective to the lack of reaction of said protective mechanism to said controlled test conditions to cause said power actuated mechanism to close said door in accordance with the other of said two predetermined modes of operation.

3. In combination, an elevator door control, said door control having protective mechanism'etfective when actuated to cause stopping of the elevator door during its closing movement, testing means effective to test the operation of said protective mechanism incident to the car stopping at al iloor landing, and circuit controlling means operable from a lirst condition to a second condition, said circuit controlling means when in said rst condition being to reduce the speed of closing said door below normal closing speed, said circuit controlling means being actuated to said second condition by said operation of said protective mechanism in response to said testing means.

false operation to render said `4. In-combination, an elevator door control, 'sa'iddobri control having protective mechanism for stopping the elevator door during its closing movement, alarm initiating means, means for reducing the speed of the door during its closing movement, testing means to test the operation of said protective mechanism incident to the car stop` ping at a floor, and circuit controlling means lresponsive to initial door opening and actuable by operation of said protective mechanism in response to said test by said testing means to render said alarm initiating means, said speed reducing means and said testing means inoperative.

5. In a control for a door of an elevator car in which mechanism is provided wihich is responsive to an object being in the path of said door to detect the presence of said object before striking said object, testing means actuated incident to the car stopping at a floor landing momentarily to stimulate false operation of said detecting mechanism to test the operation thereof, door-open means, door-close means, timing means to cause said door-close and said door-open means to establish a period during which the door remains open at a floor land- -ing to eect passenger transfer, alarm initiating means operably controlled by said testing means and said timing means for initiating an alarm at the end of said period under conditions where no such false operation of said detecting mechanism occurs, and means to reduce they speed of the door in closing operably controlled by said testing means, said testing means being responsive to said alarm initiating means and said'speed reducing means inoperative.

' 6.A monitoring and alarm initiating device for use with a control o f the door of an elevator car, said car serving several floors of a building, said control including protective mechanism to limit the force with which the door strikes an object in its path w 'le said door is closing, said device comprising, protective-mechanism-actuating means-operable incident to the car stopping at any of said oors in response to a call to causeoperation of said protective mechanism, detectingV means responsive to such operation of said protective mechanism by said ac-v tuating means, such door-close speed reducing means, audible and-visual alarm initiating means for initiating an alarm as said door begins closing, said audible and visual alarm initiating means and said door-close speed reducing means being rendered inoperative by operation of said detecting means, and means to maintain the alarm and reduced door closing speed, once initiated, until the door reaches its fully closed position.

7. An elevator installation in which an entrance-way is provided for the elevator car, in which a door is provided for said entrance-way, in which power mechanism including a reversible direct current motor is provided for operating said door, in which switching means is provided for variably connecting the armature of said motor to a source of direct current to cause operation of said mechanism to open and close said door, and in which safety mechanism responsive to the presence of a person in said entrance-Way is provided for causing operation of said switching means to disconnect said armature from said source thereby discontinuing the closing operation of said door by said power mechanism; characterized in that second switch means is provided to cause said safety mechanism to be actuated momentarily during the opening cycle of said door, that alarm initiating means is provided to initiate an alarm, that circuit controlling means is provided to reduce the amount of direct current to said armature to cause the door to close at a speed slower than normal closing speed, and that disabling means responsive to actuation of said safety mechanism by said second switching means is provided for rendering said circuit controlling means and said alarm initiating means inoperative upon such actuation of said safety mechanism.

8. In an elevator installation in which the elevator car is provided with a door, in which a hoistway door is of said car door and said hoistway door and vertically substantially from the oor of the car to scan a person of average height, each tube having a control connected to its antenna, in which means for applying direct current voltage to the anode-cathode circuits of said tubes of a value above the sustaining voltage of the tubes but insuicient to break down the tubes is provided, in which means for applying alternating current potential with respect to ground to a point in the anode-cathode circuit of each tube and to said sight guard isY provided, said alternating current potential applied to said sight guard causing said sight guard to shield said tubes and antenna against unwanted firing of said tubes by ground potential on said car door and in addition causing each antenna to have an alternating current potential of a value determined by the ratio of the antenna to ground capacity to the sight guard to antenna capacity, said potential of each antenna being insuflicient to ire the tube for which the antenna is provided but upon a person moving into the zone of influence of s uch antenna to increase the antenna to ground capacity being brought suiciently near ground potential to lire such tube, in which switching means is provided responsive to the ring of any tube to prevent operation of said power operating mechanism to close said doors, in which a sight guard is provided for each hoistway door electrically insulated therefrom, and in which means for applying to said hoistway door sight guards alternating current potential with respect to ground in phase with the potential applied to said carv door sight guard is provided to prevent unwanted iring of said tubes by ground potential of said hoistway doors, characterized in that circuit controlling means to reduce said alternating current potential applied to said hoistway door sight guard to a value slightly below the value necessary to prevent unwanted tiring of any of said tubes by ground potential on said hoistway doors is provided to cause any of said tubes to fire and said switching means to be actuated incident to the opening of said car and hoisting doors at a oor, means to cause said door to close at a slower than normal closing speed is provided, and means to initiate an alarm is provided, said means to cause said door to close at a slower than normal closing speed and said means to initiate an alarm being rendered inactive if said tube is caused to re by said reduction of said potential applied to said hoistway door sight guard.

V9. In combination with a control for the door of an elevator car serving several oors of a building, said car having an entrance-way, said control having light ray type protective mechanism, in which a light source emits a light beam, in which said'light beam is directed across said entrance-way upon a photo cell to cause conduction in said photo cell, in which interruption of said light beam by an object in the path of the elevator door causes said door control to stop said door during its closing movement to avoid striking said object, means to reduce the intensity of said light beam incident to the car stopping at a loor in response to a call to cause said protective mechanism to be actuated, means to reduce the speed of closing said door under conditions where said protective mechanism is unactuated by said intensity reducing means, and means to initiate an alarm under conditions where said protective mechanism is so unactuated, said means to reduce the intensity, said means to reduce the'speed of closing and said means to initiate an alarm being disabled as said protective mechanism is so actuated.

Referencesy Cited inthe file of this patent UNITED STATES PATENTS 2,634,828l Bums v-- Apr. 14, 1953 2,695,991 Atkinson Nov. 3o, 1954 2,785,392 Sorensen Mar. 12, 1957

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