Panel mounted switch enclosure

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to control boxes for housing electrical swt ches and .s particularly applicable to control boxes for ins alia ions requiring varying numbers of switches such as elevator car stations.

2. Description of the Prior Art

It is conventional in modem elevator systems to provide a series of buttons in each car with which passengers may select ‘^^{e floor t0}.^wh'ch they desire to be transported. The control to as a carstation.^SWItCheS ™ ^C°^mm°^{nly referred} int» ^^ety °^{f other switches} are also normally incorporated into the car station. Elevator safety codes require that an brouXT ^St°^P T ^{be provided with} which the can can be brought to an immediate stop by passengers in the event of an emergency. Usually a door hold button is also provided with which passengers may override the automatic door closing circuits when necessary. ‘1* cir

Quite often other switches are provided such as a light switch for the interior lighting of the cab, a fan switch for the cab ventilating system, an out of service switch whereby the particular car can be removed from the automatic group suswitch°^ryh^COnK °^{Perated inde}P^endent|y and/or an M.G.

itch whereby the motor generator set which controls the movement of the car can be shut down. In many installations 30 these latter switches are enclosed behind a locked slidine panel so that only authorized personnel can operate them ⁶

In any event the switches other than the car call switches are fairly well standardized for a particular line of elevator haveT ^mStance’^a P^articular line of car stations may only 35 have the emergency stop button and a door hold button in adwould have^eid^Cart^Call1^bUttOnS· ^A °^{f the Car Stations in} ‘he ^e would have identical emergency stop and door hold switches of fl»n ^nUn^^eiK° >T ^Ca^bUtt°^{nS W0U,d vaf}y ^{with the} umber of floors in the building in which the car was installed.

A car call station large enough to accommodate car call ^b“°^S.^f°^r^max,mum number of floors in an installation in mad'h ^part'^{CaIar hne of car caI1} stations is utilized could be made standard but since this number could far exceed the erage number of car call buttons required it could be very wasteful. A special car call station can be provided for each insidered^>thai¹⁰'^WeVat*'^beC°^{meS when} * ^is «>n! ί^d n 'J ^common Practice to flush mount the car station m the wall of the cab, the cabs themselves have to be nrov^rif h τ' ^thu^{ee Standard Size Car stations can} be ⁵⁰Proved for each hne, but again this requires variations in the construction of the cabs. The car stations are flush mounted not only for esthetic reasons, but also because of the depth of present day car stations, they would take up an inordinate ttewa” ‘^{n tbe if they Were mounted fla}‘ against

SUMMARY OF THE INVENTION

In accordance with this invention a switch enclosure with a fin very slim profile is mounted flat against a structural panel The shm profile is made possible by short stroke switches which hemselves are slim in profile. The unit can be made any X “7 ^{tO acc}°^{mmodate a} desired number of switches. Therefore, a standard knockout in the panel suffices 65 for sw.tch enclosures with any number of switches „7^{e SW}!^tcb enclosure is in the form of a broad thin conduit composed of a flat base section fastened to the panel and a cover plate with a U-shaped cross section. The switches are operated through openings in the cover plate. The switch con 70 tacts are composed of two flat strips of XctricZy conducfive’ bowedTTh' “ °^{Veriap end} ‘° ^end· °^e °^f‘he strips is hTZ th ^Whe” *ί ’^{S depressed a bu}«°n Placed in an openoAh ^h_f, ^C°^{Ver P ate}’ “ ^{Comes into} contact with projections on the other strip to complete an electrical circuit. Since one 75 of the contacts on each switch is for the common voltage lead :x^gh*:,^{s£np of conductive materiai may be} -d MX

Preferably the stationary contact for each switch is premounted on the base plate. The bowed member or movable contact is cemented to the cover through an electrically nonconducting spacer. The bow in the spring materialmaT wall^So?^ethe^UttOb I ^{The baSe P}*^{ate isfas}‘ened to the wall of the cab at the installation. When the cover plate is the panel. The standard receptacle can be made large enough be nuZ^m° th^{te any number} standard switches too deep to be placed m the conduit which in a preferred embodiment of the inventxon is only slightly more than a half inch deep Furthermore certain switches and indicators can be placed fn the receptacle behind a locked panel if desired. ΐΛο such deep switches or locked panels are required, the receptacta s^Chort ‘u^mere'^{y a COnduit t0 route the w}ires for the short stroke switches behind the panel.

It is therefore a first object of the invention to provide an numbers of^SXh^ees^C'°^{SUre inStallation} squiring varying ca!^tsta^ation°f»^d °^bjeCt°^{f tbe inventi}°ⁿ ‘° Provide an improved car station for use with elevators installed in buildings with the e'levator'caK °^{f fl}°^{OrS which does} require customizing

It is a third object of the invention to provide an improved car station as described in the second object which protrudes ί minimum amount into the cab. ^{P aes a}

It is a fourth object of the invention to provide an improved car station as described in the previous objects which wffl also accommodate other standard switches some of which may be protected from unauthorized operation. ^y

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevation view with parts cut awav of a switch enclosure according to this invention.

FIG. 2 is a cross-sectional view taken along lines II-II of the switch enclosure shown in FIG. 1.

in FIG. 1 ^{1S 3 Cr}°^SS‘^{SectionaI view} taken along the lines ΙΙΙ-ΠΙ

DESCRIPTION OF THE PREFERRED EMBODIMENT elA^efeoⁱⁿr° ^HG· ³’ ^kWi“ ^{be seen thata} standard receptacle 3 is flush mounted behind a standard opening in the pa^el 1 of an elevator cab. A duct 5 connected to the bottom of the receptacle 3 serves as a conduit for the electrical wiring the c^earⁿT™ic^Ca°n‘Th * ^travelin§ ^cab!e connected to inches in denth Th ^{reCeptacle 3 ma}V ^be ° the order of 2 inches in depth. The portion of the control box mounted on the outer facing of the panel I is composed of a base plate 7 9a (s^ae^Ce°FIG^P2? ^{bent at 9}°° ^{to fo}™ ^sides

Γ .or' ²^{When ln place the base} p^{|ate 7} and cover cte 3 αΖ.Γ h°th^dUit ^^{iCb COmmunicates} with the receptacle 3. Although the conduit thus formed is shown extending th ?th- ^{y UP}7^{rd fr}°^m ‘^{he receptac,e 3} it is to be understood SeXrxs ^{orientated in any wi}°^b10^ h^T¹ °^f?^eh^bT^{e Plate 7 iS SeCUred} ‘° ^the P^anel 1 by receptacle 3 ^aTh! ^a,s° ^se=^ures ‘he upper portion of the receptacle 3. The upper end of the base plate 7 is likewise fastened to the panel 1 by 10-32 hardware 8 which also passes through an angle 11 which supports the panel 1 The location of the upper fastener is dependent of the number of S_sn a particular control box. The hole through the pane?! and the angle 11 can therefore be drilled to suit in the field Another angle 13 is supported by the same hardware and el r^{th its flange extending h}™3,590,331

The cover plate 9 in addition to having sides 9α has an upper end section 9b which terminates in a downward extension 9c. The extension 9c fits into the slot between the flange 13 and the panel 1 to serve as the upper support for the cover plate 9. The cover plate is held in place by a screw 15 which fastens the lower end 9d to another angle 17 connected to the panel 1 by 10-32 hardware 18. The depth a of the cover plate 9 may be typically on the order of nine-sixteenths of an inch as in the preferred embodiment described. This slight intrusion into the cab does not detffict from the appearance of the car station and presents minimal obstruction.

In order to utilize the slim profile car station a special switch which is relatively thin and has a short stroke must be employed. In the interest of economy, a common contract for each switch can be utilized. In a preferred embodiment ofthe invention the static member of the switch is composed of a strip of electrically conductive material. Preferably the contact is made of a spring material such as tin plated phosphorous bronze which is preformed to the shape shown in FIG. 2 with ridges 19α and b projecting away from the base plate 7. The contact 19 is secured to the base plate 7 which is constructed of electrically nonconductive material by electrically nonconductive hardware such as nylon screws 21. The heads of the screws 21 are made long enough so that they may 25 serve as an intermediate support for the cover plate 9. A separate stationary contact 19 is provided for each switch. Separate leads 23 are shown soldered to each static contact member 19. Of course, other methods of fastening these leads such as the use of commercially available connectors can be 30 utilized. The leads 23 are routed down through the passage 24 in the conduit and into the receptacle 3. *

The movable contact members of the switches are also constructed of electrically conductive spring material siich as tin plated phosphorous bronze and are preformed with a bow 35 about a transverse axis. The static contact 19 and movable , contact 25 are orientated end to end with a substantial portion of each contact member overlapping the other as can be seen best in FIG. 2. The height of the bow in the movable contact member 25 exceeds the height of the projections 19α and b on the static contact 19 so that these portions of the contacts are not touching when the movable contact 25 is in its preformed condition. A strip of insulating material 27 such as a polyethylene terephthalate tape (available under the name Mylar polyester tape) or nylon is placed between the static ⁴⁵contact 19 and the turned up free end 25α ofthe movable contact to prevent electrical conduction through these portions of the contacts.

Displacement of the movable member 25 is affected by the button 29 which protrudes through an opening in the face plate 9. Conventionally such buttons are circular although any shape button could be used. They are constructed of electrically nonconducting material such as polycarbonate and are held in place by the spring force of the movable member and the flange 29α. Preferably the flange is rectangular as shown in FIG. 1 so that it bears against the insulating block 33 to prevent rotation of the numbered button. When a passenger presses the button 29 the movable member 25 is caused to flatten out until it comes in contact with the projections 19α and b on the associated static contact 19 thereby completing the electrical circuit. The tip 25α of the movable member moves horizontally across the insulating member 27 as the bow in the movable member 25 is flattened out. A knob 29b in the center of the button assists the movable member 25 in 65 making good electrical contact with the projections 19α and b on the static contact. When the button is released the movable member 25 can assume its bowed shape thereby breaking the electrical circuit.

As can be seen from FIG. 1, the movable members 25 of 70 two or more switches can be cut from the same sheet of material. Each bowed section can therefore be displaced independently yet only one return lead 31 is required. Again this lead may be soldered as shown or fastened in some other manner to the common contacts. These common contacts can 75 be formed in long sheets and then cut to order for the desired number of switches. The common contacts 25 are cemented to the insulating block 33. The base plate 7 is of course made of electrically nonconductive material. Since the cover plate 9 is constructed of stainless steel or some other metal for appearance and durability, the inner surface of the cover plate 9 is covered with insulation such as Mylar insulating tape; This is required by elevator codes which require that certain specified air gaps must be provided between uninsulated elec¹ trical conductors and uninsulated surrounding metallic members.

Preferably the insulating block 33 is cemented to the inside of the cover 9 so that the spring action of the movable contacts 25 maintains the buttons 29 in position for assembly. The common strip 25 and cover plate 9 with the appropriate number of holes can be prefabricated in the shop to accommodate any desired number of switches. The back plate 7 with the appropriate number of static contacts 19 can also be assembled in the shop. In addition the cabs are prefabricated with the standard size opening and receptacle 3 already installed. In the field, the holes are drilled through the panel of the cab and the angle 11 at the appropriate point depending on the length of the base plate 7. The angle iron 13 and base plate 7 are then secured to the panel 1. When the lip 9c ofthe front cover 9 is placed in position over the angle 13 and the lower end 9d is moved into position with respect to the angle 17, the static members 19 and movable members 25 come into operating position with respect to each other.

A number of standard switches can be located in the receptacle 3 with their operating members protruding through an opening in the cover plate 1. Generally these switches are the ones which are too deep to fit in the conduit formed by a back plate 7 and the front cover 9 although they need not be. Such switches could include the emergency stop button 37, the door hold button 39 and the toggle switch for the cab interior light 40 included in the car station illustrated. These switches can be mounted on horizontal straps 43 which are secured to the sidewalls of the receptacle 3. Numerous other switches could be added to or replace those shown. Furthermore, a sliding lockable cover plate could be provided over at least a portion of the receptacle 3 for protecting selected switches, such as the motor generator switch, from unauthorized operation. Alternatively, these switches could be key operated. It is contemplated by this invention; however, that a standard size be established for the receptacle 3 so that either one or at least only a very few cab and receptacle combinations need be established.

It can be seen therefore that with the standard receptacle 50 and opening in the cab wall, the back panel 7 with the associated static contacts and the front cover 9 with its associated movable contacts can be fabricated to any length necessary to accommodate the desired number of car call switches without affecting cab construction. It should be appreciated that all of the switches in this portion of the control unit need not be identical as shown. They may be of different types as long as they fit within the narrow conduit formed by the back plate 7 and the front cover 9. In addition it can be appreciated that all of the car call buttons need not be in a single line. For instance, the buttons could be arranged in two vertical rows with the common contacts 25 all arms of a single sheet of spring conductor with the common connector down the center.

Although the invention has been described as applied to an elevator car station, the principle could be applied to control units used for other purposes. For instance even in the elevator field smaller units could be employed for the up and down hall call switches conventionally provided at each landing. In such use only two switches need be provided and the receptacle could be reduced in size to where it was only a small tube of sufficient diameter for the wiring to pass through. It would therefore be unnecessary to recess the hall call button assembly in the door jamb or wall adjacent the jamb as is now done.