US3231784A

US3231784A - Stage lighting system

Info

Publication number: US3231784A
Application number: US288858A
Authority: US
Inventors: Ross O Major
Original assignee: Major Corp
Current assignee: Major Corp
Priority date: 1963-06-13
Filing date: 1963-06-13
Publication date: 1966-01-25
Anticipated expiration: 1983-01-25

Description

Jan. 25, 1966 R. o. MAJOR STAGE LIGHTING SYSTEM 5 Sheets-Sheet 1 Filed June 13, 1963 INVENTOR.

II Jays 0J1 W 2? 1 La #2314 MM Jan. 25, 1966 R. o. MAJOR STAGE LIGHTING SYSTEM 5 Sheets-Sheet 2 Filed June 15, 1963 lu l.

INVENTOR. J56 0.117

Jan. 25, 1966 R. o. MAJOR 3,231,784

STAGE LIGHTING SYSTEM Filed June 13, 1965 5 Sheets-Sheet 3 UZYM, 7/7 4 Wm aw Jan. 25, 1966 R. o. MAJOR 3,231,784

STAGE LIGHTING SYSTEM Filed June 13, 1963 5 Sheets-Sheet 5 1 NVEN TOR. d yqjofi United States Patent 3,231,784 STAGE LIGHTING SYSTEM Ross 0. Major, Glenview, lll., assignor to The Major Corporation, Chicago, Ill., a corporation of Illinois Filed June 13, 1963, Ser. No. 288,858 14 Claims. (Cl. 315-312) This is a continuation-in-part of application Serial No. 159,333 filed December 14, 1961, now abandoned.

This invention pertains generally to lighting systems for auditoriums, theaters, or the like, and particularly relates to improved means for selectively applying varying potentials to separate theater lighting circuits.

A well equipped auditorium for presenting dramatic and musical productions may have from twenty-five to over fifty lighting circuits or even more. Certain of these circuits may supply the auditorium or house lights, stage foot lights, side lights, overhead lights, proscenium lights, and the spot light mounted at the rear of the house. Further, certain arrays of lights disposed in one location in the auditorium, for example the overhead spot lights, may be arranged in two or more circuits. This arrangement affords great flexibility in devising creation lighting effects for dramatic productions.

Enhancing the flexibility afforded by the numerous lighting circuits, banks of dimmers, usually variable transformers or reactors, may be brought into the lighting circuits by means of a patch board. The dimmers are usually several in number whereby to supply a range of potentials to any one of the various lighting circuits. For example, in an auditorium lighting system supplied from a 120 volt A.C. source the dimmers may supply potentials ranging from zero volts to full line voltage in sixty-four or more degree increments, a total of sixtyfour or more different potentials.

It is known that lighting circuits used in the theater, the lights being usually gas filled lamps, although carbon arc spots are frequently used, are highly inductive and cause large initial surges of current. It has been found that the switching means for selectively applying the potentials to the lighting circuits must be adapted to accommodate inductive loads in the range from 20 to about 25 amps.

Prior switching means or patch boards include arrangements similar to a telephone switchboard whereby plugs and jacks connect a selected lighting circuit to a selected dimmer. This type of patch board is simple and remarkably cheap, but is electrically dangerous. Another prior art switching device comprises a sliding plug which is slid along a bar and is depressed to engage a transverse bar, large number of such crossed bars is required. Rotary switch selectors have served switching functions on prior patch boards, but this structure, as well as the two foregoing, did not afiord ease of manipulation for selecting circuits, and required a degree of expertise to obtain a precisely controlled series of lighting effects.

Therefore, an important object of this invention is to provide an improved lighting system for an auditorium, theater, or the like, which facilitates a rapid and positive switching a varying A.C. potentials to highly inductive lighting circuits.

Another object of the invention is to provide an improved patch board construction which is arranged for easy wiring into an existing theater lighting system for economical assembly as either an original equipment item or as a replacement.

Still another object is to provide an improved switching arrangement for highly inductive lighting systems and the like whereby push button actuated switches of high inductive capacity are employed.

"ice

become apparent from the following detailed description taken in connection with the accompanying drawings wherein like reference numerals designate like parts throughout, in which:

FIGURE 1 is a fragmentary side view partially in section of an auditoriumand stage showing groups of lights arranged in different sectors of the auditorium and stage and further showing an electrical control panel backstage incorporating the principles of the instant invention;

FIG. 2 is an enlarged fragmentary sectional view of the control panel shown in FIG. 1, taken generally in the direction of the arrows. along the line 22 therein;

FIG. 3 is a further enlarged fragmentary sectional view taken generally in the direction of the arrows along the line 3-3 in FIG. 2;

FIG. 4 is a horizontal sectional view, taken generally in the direction of the arrows along the line 4-4 in.

FIG. 3;

FIG. 5 is a horizontal sectional view, partially broken away, taken in the direction of the arrows along the line 5-5 inFIG. 3;

FIG. 6 is a vertical sectional view of a plunger actuated switch employed in the present invention;

FIG. 7 is a schematic view of the transfer board shown in association with the circuit diagram of the present invention;

FIG. 8- is a top view ofamodification of the invention, and generally similar to FIG. 3;

FIG. 9 is a vertical sectional view taken along the line 99 of FIG- 8;

FIG.. 10 is a perspective view showing a detail of the modified form of the invention;

FIG. 11 is a rear plan view of the modification, with certain schematic additions thereto illustrating electrical connections; and

FIG. 12 is a fragmentary exploded perspective view showing one of the mounting brackets for the switch structure.

There is shown in FIG. 1 of the drawings a forward portion of an auditorium including the auditorium proper designated generally 10, and the stage 12 which is separated from the auditorium 10 by a curtain 14. The stage area 12 is divided from a back stage area 16 by a back drop 18. It is well known that the back drop 18 and curtain 14 are each movable whereby to separate the stage area from the back stage area and to partition the auditorium area 10 from the stage area.12.

Mounted in the. backstage area 16 is a lighting control cabinet generally designated 20 which incorporates light control means made in accordance with and embodying the principles of the present invention. As shown in FIG. 1, the control cabinet 20 is mounted against the wall and may be supported further by a standard 22. which engages the floor of the backstage area 16.

The switching means enclosed by the cabinet 20 will be described in detail presently, but to fully appreciate the significance of that apparatus a description of the various lighting circuits will now be set forth. It is apparent that in any well equipped theater a multiplicity of lighting circuits are required to obtain a degree of flexibility for creating various lighting effects. Various of these lighting circuits may include several circuits controlling a bank of foot lights 24 and several more circuits for controlling an arrangement of proscenium lights 26. Other circuits supply several groups of overhead lights 28 and wing lights 30 arranged on each side of the stage area 12. Backstage 16, an independent circuit for backstage overhead or work lights 32 affords illumination to the working area. An array of spotlights now shown may be positioned in the auditorium area 10 for directing controlled illumination with respect to various parts of the stage area 12. House lights 34 may also be provided in the auditorium.

Thus it is to be recognized that the stage lighting circuits may vary in number from a minimum of say 25 upwards to 50 to 75 or more for an elaborately equipped stage lighting system. Further, dimmers are provided for varying the potential supply to each of the numerous circuits. The dimmers (not shown in FIG. 1) are usually arranged backstage closely adjacent to the lighting control cabinet 20 whereby a range of different A.C. potentials may be preset and then applied selectively to any one of the various lighting circuits.

To facilitate switching the highly inductive lighting loads between the various electrical potentials, the light control cabinet 20 includes a feeder bus panel or transfer panel 36 positioned adjacent the back wall of the cabinet 20 and a push button patch board 38 arranged on a winged door 39 of the cabinet 20. Referring now to the circuit diagram shown in FIG. 7, the feeder bus panel 36 includes twelve bus bars consecutively numbered 40 through 51, each ba-r being provided with a plurality of terminal portions 52 equal in number to the number of lighting circuits. In this case, thirty-two circuits are shown as one exemplification. A.C. potential is applied to each bus bar 40-51 through a circuit breaker 54 and a variable transformer 56, the power being supplied to the circuit breakers 54 and variable transformers 56 from a common A.C. source. It is seen that in this exemplification twelve different potentials may be applied to the feeder bus panel 36.

The push button patch board 38 includes a row of twelve switches for each of the thirty-two lighting circuits shown in the illustrative embodiment. A row of switches 58 may, for example, be electrically connected to the spotlights 34; the next row of switches 59 may operate the foot lights 24; and the row of switches 60 may afford selective dimming to the overhead lights 26, etc. Taking now the row of switches 58 as an exemplification, the first switch 62 in row 58 is connected by a wire 63 to a terminal means 64 on the bus bar 51 having a predetermined se lected potential thereon. The second switch 66 in row 58 is connected by a wire 67 to a terminal means 68 on the bus bar 50 having a second potential thereon. A third swltch 70 in row 58 is in turn electrically connected by a lead 71 to a terminal 72 on the bus bar 49 having a third and diflerent potential thereon. Each succeeding switch in row 58 is in turn connected to one of the bus bars 40 through 48 of the transfer panel 36. In a similar fashion, the sw1tches in row 59, 60 etc. are respectively connected to the feeder panel 36. When its is desired to apply to the spotlights 34 a pre-selected potential from the bus bar 49, the switch 70 is actuated; from the bus bar 50, the switch 66 is actuated; and from the bus bar 51, the switch 62 is actuated.

Referring now to FIG. 2, each of the bus bars 40-51 is fastened by screws 72 to three equally spaced insulating frame members 74. One end of each bus bar 40-51 is provided with a lug 76 for receiving the line from the variable transformer 56. The frame 74 and bus bar assembly may be mounted on a panel wall 78 (FIG. 3) which may form the back of the light control cabinet 20. A forward face 80 of the hinged door 39 of the cabinet 20 is the principal supporting member for the patch board arrangement 38 which includes, for purposes of illustration, 32 rows of identical push button actuated switches, one for each circuit.

In FIG. 4 there is shown a typical arrangement of six switches of high inductive capacity in association with a push button mechanism. This mechanism and switch arrangement is typical of that employed to operate onehalf of the row of twelve switches shown in the illustrative embodiment. Shown in elevational section in FIG. 3, the switch array and push button mechanisms both supported upon a frame 82 comprising a vertically extending base panel 83 joined to a horizontally disposed wall 84 which is joined to an upwardly inclined panel 85 which, in turn, is integrally connected to a second base portion 86 disposed at a right angle with respect to the base portion 83. A sheet of insulation 88 is interposed between the confronting surfaces of the base portion 83 and the array of switches mounted thereon, the insulation extending over the frame wall 84.

For purposes of identification the six switches shown in FIG. 4 have been numbered consecutively 89 through 94. The six switches 89-94 are generally flat and boxlike in form and are laterally spaced apart on predetermined centers along the base 83 and maintained in such position by intervening insulating spacer members 96. A pair of end spacer members 98 completes the switch and spacer sandwich which is adapted to receive a pair of through-bolts 100 with co-operating fasteners for securing the members 89-94, 96 and 98 together as a unit. The switch array is in turn secured to the base member 83 over the insulating board 88 by a plurality of fasteners 102 which are received into the insulating

spacers

96 and 98.

Referring to FIG. 2, a pocket 101 shrouding a switch terminal 116 is defined by the

spacers

96, 98 extending beyond the proximate end of the switch 89. In a like fashion, a pocket 101 is provided for each of the switches on the patch board 38 to afford physical isolation of the somewhat exposed switch terminal 116. This arrangement obviates wrapping the terminal 116 and its associated electrical conduit (not shown) with tape or other insulating material.

Referring now to FIG. 6 wherein a typical switch 89 is shown, it is seen that the construction of the switch 89 is of the plunger actuated two-point make variety. The rectangular casing 103 is provided with a cavity 104 which receives a spring biased plunger member 105. The innermost end of the plunger 105 carries a pair of contacts 106 spaced on opposite sides of the plunger 105 and rigidly mounted on a rectangular bar 108. Inwardly of the contact carrying bar 108 there is fixedly mounted on the plunger 105 a fiber spacer bar 110 positioned apart from the contact bar 108 by a first coil spring 112, the spacer 110 being shaped complementary to the bar 108. The

bars

108 and 110 both being mounted on the plunger 105 cooperate with the spring 112 to provide an over travel limiting means. More specifically, when the plunger 105 is depressed against the bias of a spring 114 within the cavity 104, the contacts 106 are urged into engagement with the spaced end portions of a pair of flat, outwardly extending

terminal plates

116 and 118. If inward travel of the plunger 105 is thereafter continued, the innermost end of the plunger 105 slides through the contact bar 108* against the bias of spring 112 until the coils of spring 112 are fully compressed against each other and against the spacer 110 fixedly secured to the plunger 105. This arrangement precludes over stressing and eliminates bending of the plate 108 whereby to ensure positive engagement of the contacts 106 with the spaced ends of the

terminals

116 and 118.

The

terminals

116 and 118 each extend outwardly of the casing 103 a distance to conveniently receive an electrical conductor (not shown). As arranged on the frame 82 the switches 89-94 have their respective terminals 116 extending outwardly of the frame 82 into a pocket 101 (see FIG. 2). The terminals 118 of the switches 89-94 are joined to a common bus bar 120, arranged in the pocket-like inner portion of the frame 82 defined by the

panels

83 and 84.

A lever arm 122 is shown in FIG. 6 cantilevering from one end of the switch casing 103 over the outermost portion of the plunger 105. The central portion of the lever arm 122 is provided with an outwardly protruding channellike portion 124 extending longitudinally of the arm 122 for receiving a tip 126 of the plunger 105. A free end portion 128 of the lever arm 122 extends away from the plunger 105 whereby as the end 128 is depressed towards the terminal 118, the plunger 105 is urged into the body of the switch to complete a circuit between the

terminals

116, 118. When the depressing frame is removed from the end 128, the spring 114 urges the plunger 105 upwardly carrying the contact bar 108 away from the

terminals

116, 118 to open the circuit.

Push button means for selectively actuating each of the switches 89-94 by depressing the lever arm 122 is secured to the second base panel 86 of the frame 82, shown clearly in FIG. 3.

The push button mechanism, generally designated 130 and shown in FIGS. 3 and 4, is typical of that which may be used for actuating six of the twelve switches in any one of the thirty-two rows of switches on the push button panel 38. A channel shaped member 131 attached to the second base panel 86 supports the push button mechanism 130 on the frame 82, and connects the frame 82 to the door panel 80, a first flange 133 of the member 131 being fixedly secured to the inner side of the door panel 80 a second flange 137 being spaced inwardly therefrom.

The mechanism 130 comprises a row of six push buttons 132 spaced on centers complementary to the spacings of the switches 89-94, each button or knob 132 being fixedly secured to a flat push rod 134. Each rod 134 extends through complementary apertures provided in the panel 80 and in the

upstanding flanges

133, 137 of the channel member 131. One end of the rod 134 projects inwardly from the second flange 137 towards the free end 128 of the lever arm 122, shown best in FIG. 3.

Each of the rods 134 has a double notched central portion 135, one end of which forms an abutment for one end of a coil spring 136, the opposite end of the coil spring engaging the second flange 137. On the opposite end of the notched central portion 135a rubber stop member 138 is positioned so as to arrest outward movement of the push rod 134 by engaging the first flange 133.

Referring now to FIG. 4 to maintain a selected push button, such as push button 132a, in a depressed position, a rocking bail 140 is provided on the mechanism 130. As it will presently appear, the bail 140 also functions to release the depressed button 132a when any other button in the mechanism 130 is pressed.

The rocking bail 140 extends at a right angle across the central portions 135- of the six rods 13.4, the bail being rotatably mounted at its ends in spaced L-shaped clips 142 secured to the channel 131. The medial portion of the bail is biased by a tension coil spring-144 to urge a corner 146- of the bail 140. into oneof two notches 135 in each rod 134, shown best in FIG. 3.. Thus, as the button 132a is depressed the projection intermediate the notches 135 pushes or rocks the corner 146 from the first notch as shown in FIG. 3 to the second notch as shown in FIG. 4.

Subsequently, when a button 132 other than button 132a is pressed, the corner 146 of the bail 1'40 is rocked from the second notch of the depressed button 132a. The previously compressed spring 136 then urges the button 132a to the extended or original position, the extending motion being arrested by the elastomeric snubber element 138.

Means for preventing two or more push buttons 132 from being depressed simultaneously is provided in the mechanism 130. Referring now to FIG. 5 more partic- 6 ularly, an elongated plate 150 is secured to the web of the member 131 and is provided with six spaced apart slots 152 each for receiving a tab 153 integral with the rod 134. On opposite sides of each slot 152 there is provided a pair of spacers 154 slidably mounted beneath the plate 150 and retained therein by a flange member 156 integral with a long edge of the plate 150. Between the two spaced clips 142 the cams 154 provide only sufficient free space for one of the tabs 153 to be interposed. Hence, when any one tab 153 is inserted within any one of the slots 152, the cams 157 on either side of the interposed tab 153 are pushed together completely filling the remaining slots 152 thereby precluding a second push button in the row from being depressed.

It is to be noted that the push rods 134 are arranged to have a predetermined distance of free travel before operatively engaging the lever arm 122, clearly shown in FIGS. 3 and 4. Further, the operative travel of the rod 134 between the two locking notches 135 is matched to the deflection of the free end 128 of the lever 122, such deflection being in turn matched to the operative travel of the plunger requisite to close the switch.

The push rods 134 are mounted for easy movement between the in and out positions. To achieve this condition in the mechanism a measure of overtravel of the rod 134 beyond the depressed position shown in FIG. 4, is inherent. This is easily understood from the arrangement of the coil spring 136:: in relation to the

spring abutments

137 and 135, it not being desirable to completely compress the spring 13611 in depressing the push button 132. The overtravel of the push rods 134 is determined by the measure of residual compressibility of the coil spring 136a beyond that of the in position. It has been found that the life of the switches 89-94 employed in the patch board 38 is greatly increased by matching the overtravel of the rods 134 to that of the contact carrying plunger 105. The matching of the comparative overtravel capabilities is in addition to matching the operative travel of the rods 134 with that of the lever arm 122 and plunger 105.

Prior to securing a group of six switches to the frame 82, the inwardly extending terminals 118 are each fastened to the common bus bar 120 which, in turn, may receive the conductor leading to the lighting circuit. This arrangement permits wiring the switches to the feeder bus panel 36 after the attachment of the switch array to the push button frame means 82.

Referring to FIG. 3, the bus bars are provided with wire receiving apertures 41a, 42a, arranged in the wall of the hollow bus bar at a right angle to the lug screw 52. A typical conductor 160 may have one end secured in the aperture 41a and have the opposite end in electrical contact with the lug 116, leaving sufficient slack in the lead 160 to permit opening of the cabinet door 39 of the lighting control cabinet 20.

When closed, the cabinet door 39 presents a pushbutton patch board having 32 rows of 12 pushbuttons each. The stage electrician may rapidly switch potentials between the twelve dimmers 56 and the thirty-two lighting circuits, each circuit of which may be loaded to twenty to twenty-five amps inductively. Being that the load resulting from the use of gas filled lamps is highly inductive, it is requisite that the plunger actuated switches have contacts and terminal members of ample size to safely accommodate such loads. For this reason the

terminals

116 and 118 are broad adjacent the contacting area within the body of the switch. Being that the circuit is broken within the switch 89 simultaneously at two spaced points a minimum of arcing occurs upon opening the switch.

Turning now to the embodiment of FIGS. 8-12, it will be understood that the feeder bus panel has been combined with the pushbutton patch board. For simplicity of illustration, a rather small pushbutton patch board is shown, comprising three vertical columns, each consisting of six pushbuttons, a total of eighteen pushbuttons,

as contrasted with the larger number heretofore discussed. Many of the parts in FIGS. 8-12 correspond directly with those heretofore shown and described, and for simplicity of disclosure, these parts are identified by like numerals with the addition of the suflix 12.

Thus, the pushbutton patch board 38b includes a panel 80b having a plurality of pushbuttons 132b mounted on members 1341). A channel-shaped member 131i) comprises a pair of angle members mounted edge to edge, and, providing parallel flanges 13712 and 13312, the latter of which is adjacent the panel 80b, and the former of which is spaced therefrom. Through-bolts 170 and nuts 172 thereon secure the two halves of the channel together and to the panel 80b.

As previously has been described, particularly in connection with FIGS. 3 and 4, a rocking bail 14012 is provided for each row of pushbuttons, and cooperates with appropriate shoulders on the members 13% for holding any depressed button down, while insuring against spring return of a prior depressed button by means of the corresponding spring 1361) whenever a subsequent button is depressed. The inner end of each member or flattened push rod 134b is engageable with the pivoted operating lever 1221) of a corresponding pushbutton switch 8%. The switches may be similar to those heretofore described in detail, or may be improved.

The switches are mounted by means of brackets 174 seen in FIGS. 8, 9, l1 and particularly 12. Each such bracket comprises a flat strap-like portion 176 having a pair of apertures 178 therein for receipt of the ends of screws 180 (FIG. 8) extending through the two-part channels 1311) at either end thereof. The apertures are tapped to receive the threads of the screws.

There are two brackets provided for each channel, respectively at the opposite ends thereof. In addition to the strap-like portion 176, each bracket includes at its outer end an elongated, right-angularly disposed flange 182 having a pair of apertures 184 therein, relatively adjacent the opposite ends. Through-bolts 186 extend through the apertures 184 in corresponding brackets, and also through the intermediate switches 89b to support the switches. End spacer plates of insulating material 98b and intermediate spacer plates 96b of insulating material also are secured by the through-bolts 186. Nuts 188 are threaded on the ends of the through-bolts, as will be understood.

All of the switches are herein designated as 89b. It will be observed that near one end of each switch near the back side thereof, there is provided a screw 190. A common bus bar 192 (see particularly FIG. is secured under the heads of all of the screws 190 for any given vertical row of switches. The intermediate insulating spacers 96b are suitably notched to accommodate each common bus bar 192. As may be seen in FIG. 11, each of the common bus bars 192 is secured to one of the lighting circuits, such as 34b, 24b and 26b, for example, respectively by means of a

wire

194, 196 and 198 secured beneath the head of a screw on a corresponding common bus bar, preferably by means of an approved eyelet type of connector.

As has now been observed, the screws 190 and common bus bars 192 are disposed relatively toward one end of each switch. Relatively adjacent the center of each switch, there is also disclosed a connecting

screw

200, or 202. As will be observed, the screws 202 are substantially longer than the screws 200.

Tubular insulating

members

204 and 206 of different length, corresponding to the length of the

screws

200 and 202, respectively encircle the

screws

200 and 202. Feeding bus bars 208 and 210 are respectively secured beneath the heads of the

screws

200 and 202 against the ends of the

insulators

204 and 206. In the illustrative example, each feeding bus bar is connected to three switches, and it will be understood that in general, a feeding bus bar is connected to all corresponding or parallel switches in whatever number of vertical rows of switches may be provided. The feeding bus bars are alternately spaced at different distances from the rear ends of the switches to provide a requisite spacing for electrical safety purposes.

Electrical connectors are provided at the ends of the feeding

bus bars

208 and 210, all of the connectors being similar. The connectors to the feeding bus bars 208 are at one corresponding end thereof, while the connectors on the feeding bus bars 210 are at the opposite end thereof. The connectors are all of the same construction, including a strap-like body 214 secured to the end of the corresponding

feeding bus bar

208 or 210 by means of screws 216 passing through the strap-like body 214 and threaded into tapped apertures in the corresponding feeding bus bar. Each connector is further provided with an offset 218, and a continuing parallel tip 220. A conductive stirrup 222 encircles each extending end 220, and has a set screw 224 threaded therethrough and confronting the extending end 220. As will be understood, a wire is inserted into the stirrup 222 and the set screw 224 is turned down against the wire to clamp the wire against the extending end 220 to make the connection.

Insofar as the actual connections are concerned, they are made to the feeding bus bars from transformers or other dimmers 5612, as previously indicated in connection with FIG. 7.

As will now be apparent, the patch board and feeder bus panel or transfer panel have now been unitized, thereby providing a simpler and more rugged construction. The various electrical components are mounted in simplifled fashion, in accordance with the embodiment of FIGS. 8-12.

While reference has been made to pushing different buttonsto apply different potentials to a given lighting circuit, it will be understood that this is principally by way of illustration. Primarily the patch board herein will be used to connect various combinations of lights to any given dimmer, whereby selective actuation of any of the various dimmers will effect concurrent changes in lighting intensity in desired combinations of lights, as set up by punching the appropriate buttons.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appendant olaims all such modifications in the true spirit and scope of the invention.

What is claimed is as follows:

1. In a lighting system for a theater auditorium and stage having a plurality of highly inductive lighting circuits supplied from source means, the combination comprising: a plurality of variable transformers connected to said source means for setting a range of different potentials to be applied to the lighting circuits; a feeder panel including a plurality of bus bars, each electrically connected to one of said variable transformers, each bus bar having terminals at least equal in number to said lighting circuits; and a push button actuated patch board having a gang of switches 'of high inductive capacity for each of the lighting circuits, a switch in each gang being electrically associated with one of said bus bars of said transfer panel, and means co-operating with said gang of switches for preventing closing of more than one switch at a time, each of said switches being a discrete switch having an operator extending therefrom and further comprising a push button having a plunger thereon engageable with said operator.

2. The combination as set forth in claim 1 wherein each switch has a first terminal and a second terminal, said switches being arranged in horizontal rows and vertical columns, wherein said bus bars comprise a pair of physically parallel bus bars each connected to the first terminals of a corresponding group of said switches, and further including an additional plurality of buses physically parallel to one another and disposed at right angles to said bus bars and connected to a second terminal of a group of corresponding switches.

3. The combination as set forth in claim 1 wherein each switch is aligned with a respective push button.

4. The combination as set forth in claim 3 and further including a front panel which is imperforate except for a plurality of relatively small apertures therein arranged in a plurality of vertical columns and a pl-unality of horizontal rows, said apertures and said push buttons being equal in number and each push button having a rearward projection extending through and substantially filling a respective aperture.

5. In a system for switching variable electrical potentials one at a time to a plurality of highly inductive lighting circuits, the combination comprising: a feeder panel board having a plurality of bus bars mounted thereon, each bus bar providing connection means for one source of A.C. potential; and a patch board for selective switching of ones of the variable potentials to respective ones of the lighting circuits, said patch board including frame means having a plurality of ganged push buttons mounted thereon for one-at-a-time actuation, and a plunger-actuated springbiased two point make switch having a lever arm thereon coacting with one of said push buttons to open and close said switch for breaking and making a circuit between one of said bus bars and an associated lighting circuit.

6. In a system for switching variable electrical potentials one at a time to a plurality of highly inductive lighting circuits, the combination comprising: a feeder panel board having a plurality of bus bars mounted thereon, each bus bar providing connection means for one source of A.C. potential; and a patch board independent of said feeder panel for selective switching of ones of the varying potentials to respective ones of the lighting circuits, said patch board including frame means having mounted thereon a plurality of gangs of push buttons, and a plurality of complementary gangs of plunger actuated switches, each gang of switches having one switch electrically connected to each one of said bus bars, each push button including an axially advanceable rod having a first range of lost axial motion, said switch plunger having a second and smaller range of lost motion, and means coacting With said rod and switch plunger to accommodate the travel of said rod to the travel for closure of said switch plunger.

7. In a push button patch board for switching a variety of different inductive loads to variable electric devices for dimming theater lights, the combination comprising: a frame, an array of push button mechanisms on said frame arranged in rows, the push button mechanism of each now having first means for limiting ouertravel of said push buttons; and a plurality of discrete plunger actuated switches on said frame grouped in rows and re spectively aligned with said push button mechanisms, each row coacting with a respectively corresponding row of push buttons, each switch having second means complementary to said first means for limiting overtravel of the contact actuating plunger to prevent bending of the contacts, the switches in each row being arranged sideeby-side and maintained in a spaced apart relationship by insulating members sandwiched between adjacent switches, each row of switches having a bus bar electrically connected to one terminal on ach switch in said row and adapted for connection to an inductive lighting circuit load, each of the other terminals on the switches in each row being adapted for connection to separate ones of the variable electric devices.

8.. In a push button patch board for switching a variety of different inductive loads to variable electric devices for dimming theater lights, the combination comprising: an array of push button mechanisms on said frame arranged in rows, the mechanism of each row including a plurality of push buttons spaced on predetermined centers, said push buttons including axially movable rod members coacting with means for releasing a depressed button when any other button in said row is depressed, and a plurality of discrete plunger actuated switches on said frame grouped in rows, each row coacting with a respectively corresponding row of push buttons, the switches in each row being maintained on said predetermined centers by insulating spacer means secured to said frame, the plunger-s of said switches being oifset from the respective nod members, and means on each of said switches engaging the plungers thereof and coacting with the respective one of said nod members for depressing said plunger to close said switch.

9. In a push button patch board for switching a variety of different inductive loads to variable electric devices for dimming theater lights, the combination comprising: a frame; an array of push button mechanisms on said frame arranged in rows, the mechanism of each row including a plurality of push buttons spaced on predetenmined centers, said push buttons including axially movable rod members coacting with means for releasing a depressed button when any other button in said now is depressed; each rod member having first overtravel limiting means associated therewith; and a plurality of discrete plunger actuated switches on said frame grouped in rows, each row being in substantial alignment with and coacting with a respectively corresponding row of push buttons, the switches in each row being arranged side by side and maintained in a spaced apart relationship by insulating members sandwiched between adjacent switches, the plunger of each of said switches having second overtravel limiting means associated therewith, and means on each of said switches engaging the plunger thereof and coacting With the respective one of said rod members for depressing said plunger to close said switch, said first limiting means being compatible with said second limiting means to permit overtravel of said plunger Without bending of the switch contacts.

10. In a system for selectively connecting a plurality of electric sources of potential to a plurality of electric utilization circuits, a patch board comprising frame means, a plurality of discrete switches each having first and second terminals and means for inter-connecting said terminals arranged in mutually perpendicular rows and carried from said frame means, a like plurality of pushbuttons carried from said frame means, means operatively connecting each pushbutton with a respective switch for selectively inter-connecting the first and second termi- 113.118 of a switch, a plurality of parallel bus bars each connected directly to the first terminals of each switch in a corresponding row and to a source of potential, and a plurality of parallel feeder buses disposed at right angles to said bus bars and directly connected to a second terminal of each switch in a now perpendicular to the last mentioned row of switches, each of said feeder buses being connected to a utilization circuit.

11. The combination as set forth in claim 10 wherein the feeder buses are spaced from the switches by means including insulating spacers.

12. The combination according to claim 11 wherein the spacers are of two different lengths, alternate feeder buses being spaced different distances from said switches, feeder buses spaced apart by one feeder bus being spaced the same distance from said switches.

13. The combination as set forth in claim 10 wherein said switches are supported from said frame means respectively in alignment with said push buttons.

14. The combination as set forth in claim 13 and further including a front panel which is imperforate except for a plurality of relatively small apertures therein, said apertures being arranged in a plurality of vertical columns and a plurality of horizontal rows, said apertures and said 1 1 12 push buttons being equal in number and said push buttons 2,935,577 5/ 1960 Dumke 200-5 X having rearward projections extending through and sub- 3,004,193 10/ 1961 Bentham et a1 315295 stantially filling said apertures respectively.

FOREIGN PATENTS References Cited by the Examiner 5 1 111 68 7/1961 G rman UNITED STATES PATENTS 564,951 7/ 1896 Washburn 315-294 JOHN W. HUCKERT, Primary Examiner.

2,344,441 3/1944 Lorenz 317-120 2,720,613 10/1955 Lustig 317 99 JAMES D'KALLAMEmmmer' 2,864,035 12/1958 Davis 315--255 X 10 D. E. PITCHENIK, R. SANDLER, Assistant Examiners.

Claims

1. IN A LIGHTING SYSTEM FOR A THEATER AUDITORIUM AND STAGE HAVING A PLURALITY OF HIGHLY INDUCTIVE LIGHTING CIRCUITS SUPPLIED FROM SOURCE MEANS, THE COMBINATION COMPRISING: A PLURALITY OF VARIABLE TRANSFORMERS CONNECTED TO SAID SOURCE MEANS FOR SETTING A RANGE OF DIFFERENT POTENTIALS TO BE APPLIED TO THE LIGHTING CIRCUITS; A FEEDER PANEL INCLUDING A PLURALITY OF BUS BARS, EACH ELECTRICALLY CONNECTED TO ONE OF SAID VARIABLE TRANSFORMERS, EACH BUS BAR HAVING TERMINALS AT LEAST EQUAL IN NUMBER TO SAID LIGHTING CIRCUITS; AND A PUSH BUTTON ACTUATED PATCH BOARD HAVING A GANG OF SWITCHES OF HIGH INDUCTIVE CAPACITY FOR EACH OF THE LIGHTING CIRCUITS, A SWITCH IN EACH GANG BEING ELECTRICALLY ASSOCIATED WITH ONE OF SAID BUS BARS OF SAID TRANSFER PANEL, AND MEANS CO-OPERATING WITH SAID GANG OF SWITCHES FOR PREVENTING CLOSING OF MORE THAN ONE SWITCH AT A TIME, EACH OF SAID SWITCHES BEING A DISCRETE SWITCH HAVING AN OPERATOR EXTENDING THEREFROM AND FURTHER COMPRISING A PUSH BUTTON HAVING A PLUNGER THEREON ENGAGEABLE WITH SAID OPERATOR.