(cid:51)(cid:68)(cid:74)(cid:72)(cid:3)(cid:20)(cid:3)(cid:82)(cid:73)(cid:3)(cid:20)(cid:27)
`
`Daktronics, Inc.
`STAGE EXHIBIT 1011
`EXHIBIT 1011
`
`

`
`June 28, 1960
`
`Filed Nov. 5, 1957
`
`G. C. IZENOUR
`SCENERY HANDLING APPARATUS
`
`2,942,879
`
`8 Sheets-Sheet 2
`
`_,
`
`FIG.3
`
`INVENTOR.
`o/.Et:J.Rv£ C. /.Z.E/V?JVR
`
`BY
`
`Page 2 of 18
`
`

`
`June 28, 1960
`
`Filed Nov. 5, 1957
`
`G. C. IZENOUR
`SCENERY HANDLING APPARATUS
`
`2,942,879
`
`8 Sheets-Sheet 3
`
`INVENTOR.
`i!?&CJR~£ C:./z£/Yt:lVR
`
`BY
`
`FIG.4
`
`Page 3 of 18
`
`

`
`June 28, 1960
`
`Filed Nov. 5, 1957
`
`G. C. IZENOUR
`SCENERY HANDLING APPARATUS
`
`2,942,879
`
`8 Sheets-Sheet 4
`
`•
`
`FIG.6
`
`FIG.l
`
`44.
`
`FIG.5
`
`FIG.B
`
`INVENTOR.
`C:&PR4'£ G. ./.z£/VPPR
`
`BY
`
`Page 4 of 18
`
`

`
`June 28, 1960
`
`Filed Nov. 5, 1957
`
`G. C. IZENOUR
`SCENERY HANDLING APPARATUS
`
`2,942,879
`
`8 Sheets-Sheet 5
`
`FIG. 9o
`
`TO FIG;
`9C
`
`TO FICi; 9b
`
`INVENTOR
`o/£t?R<F.E c. LZ£/YOI!/~
`BYk5.~~
`
`ATTORNEY
`
`Page 5 of 18
`
`

`
`June 28, 19~0
`
`Filed Nov. 5, 1957
`
`G. C. IZENOUR
`SCENERY HANDLING APPARATUS
`
`2,942,879
`
`8 Sheets-Sheet 6
`
`Fli'CJ'1 FIG: 90
`
`....--1-----f-"':::~~~B:
`
`/4/
`
`. ~!
`.-----~--~ .. ~
`
`I
`
`1/Ba.
`
`/164
`
`//0
`
`-------
`
`TO FIG. 9C
`
`FIG.91J
`
`INVENTOR
`tF&aRtS'& C./z.c/Yo<Y.e
`BY~s;p~
`ATTORNEY
`
`l
`
`Page 6 of 18
`
`

`
`June 28, 1960
`
`Filed Nov. 5, 1957
`
`G. C. IZENOUR
`SCENERY HANDLING APPARATUS
`
`2,942,879
`
`8 Sheets-Sheet 7
`
`FROM Flt!i: 9 b
`
`82 (Fifi:.90)
`~
`
`/176
`
`CTL.
`(FI(i; 90)
`
`r / . (FI~ 90)
`
`F/G.9c
`
`INVENTOR
`o/EOR~.E C: /Z.EA'OV.R
`8~5./.p~
`
`ATTORNEY
`
`Page 7 of 18
`
`

`
`June 28, 1960
`
`Filed Nov. 5, 1957
`
`G. C. IZENOUR
`SCENERY HANDLING APPARATUS
`
`2,942,879
`
`8 Sheets-Sheet 8
`
`F/G./0
`
`INVENTOR.
`9E.tJR~E C:.Lz£/YOUR
`
`BY
`
`-"
`
`l
`
`Page 8 of 18
`
`

`
`United States Patent Office
`
`2,942,879
`Patented June 28, 1960
`
`1
`
`2,942,879
`SCENERY HAN:DLING APPARATUS
`George C. Izenour, 10 Alston Ave., New Haven, Conn.
`Filed Nov. 5, 1957, Ser. No. 694,683
`37 Claims.
`(CI. 272--22)
`
`The present invention relates to apparatus for handling
`scenery, as in a theatre, and has as its broad purpose the
`provision of a new system for operating scenery in order
`to change sets at different times, as during a performance.
`In typical theatre construction, the stage is provided
`with scenery that is suspended from lines or cables ex(cid:173)
`tending from above, and the scenery is changed by lifting
`one or more scenery units and lowering others. The
`region where the raised sets are stored, to be lowered
`Selectively as demanded, is called the "flies" or the "l'ly(cid:173)
`loft." The wings of the theatre are to the left and
`right of the stage, and the entire area of the stage, above
`the flies, is covered by a grid or gridiron. The "high
`iron," i.vhich is the supporting structure for the roof over
`the stage, is spaced above the gridiron suffiCiently higher
`to ·provide the· necessary working space.
`For literally centuries there has been a standardized
`type of construction that is used almost universally at
`the present time for raising and lowering the scenery.
`If a single fiat is considered as a typical unit of scenery,
`there will be multiple spaced lines (four lines is usu·any
`standard) attached to horizontal pipes or battens sup(cid:173)
`porting this fiat. These lines extend upward from the
`fiat to individual pulleys supported by the gridiron, and
`these lines all extend horizontally to one side of the
`stage. Each line has a separate pulley, normally where
`it reaches the gridiron, but all of the lines will extend
`.to a common pulley at the lateral edge of the gridiron.
`Each common pulley and all the individual pulleys hav(cid:173)
`ing lines to a batten are in a straight line extending
`:directly crosswise of the stage. Each set of lines extends
`.over its common pulley to a common counterweight.
`The pulleys for the different sets are in a row at one side
`-of the stage, and the counterWeights hang down below
`them, requiring a vertical operating space that equals
`the distance that the scenery must be lifted.
`Each cc:.:..1.mon pulley is limiied almost invariably to
`four lines so that large and heavy sets may require special
`treatment. The alignment of each group of individual
`pulleys transversely across the stage involves complica(cid:173)
`.tions when sets are to be handled that have substantial
`,depth.
`A gallery is usually provided aloft n:ear the common
`:pulleys at the edge of the gridiron, where a stage hand
`·tan load weights to balance each new unit of scenery.
`The space below the common pulleys Where lines extend
`.1o the counterweights is waste. Operating lines also hang
`.down to stage level for manual operation for lowering
`:and raising the scenery. This represents an allocation
`·of space between the stage and one of the wmgs that may
`:be needed for other purposes occasionally.
`The present invention has as a broad object the prO(cid:173)
`cvision of new and improved scenery-handling apparatus.
`.A more particular object of the invention is to eliminate
`-counterweights, and the hazard of plummeting counter(cid:173)
`weights, along with the need for a counterweightloading
`:gallery and the space requirement for travel of the counter(cid:173)
`weights. A further object of the invention is to enable 70
`lre·e selection of the scenery-handling station, completely
`':Without restriction in: relation to the Iinecoperating mech-
`
`2
`anism. A still further object is to clear the spate ·at the
`lateral limits of the stage formerly allocated to ·scenery
`operating apparatus, to make it freely available for
`other use.
`An additional object resides in the provision of hovei
`apparatus that eliminates the manual operation of pulley~
`operating lines, by substituting remote-controlled elecffi"
`tally powered apparatus. Through this feature -of the
`invention, the change in scenery can be ·accomplished
`10 at greater speed (a most important consideration iii scm~
`dramatic presentations) and it may be accomplished·at
`an architecturally convenient location. The simple oper•
`ation of electrical controls is effective to shift any desired
`sets as fast as desired, limited only by the motor power
`15 and the strength of the lines and of the sets.
`In another aspect, a basic object of the present invention
`is to provide novel highly flexible apparatus for handiing
`scenery. The novel stage organization made possible
`by this aspect of the invention is not restricted and con-
`20 fined to the previous requirement of each group of iines
`extending to a comtnon pulley, nor to the use of a!ly par(cid:173)
`ticular :immber of lines for a unit of scenery nor to the
`previous requirement that the individual pulleys for lines
`of a group· are to be in a straight line extending across
`25 the stage;
`An important feature of the present invention resides
`in the use of electric motor driven winches for individual
`lines to a set and in the coordination of such motors.
`Through this basic departure from standard practiCe,
`30 each motor and each winch can be located wherever may
`be conve11ient. The control apparatus may also he lo(cid:173)
`cated at any desired position. This flexibility at once
`opens up the possibility of broad architectural change
`from conventional back-stage
`theatre designs. The
`35 side of the stage previously reserved for counterweights,
`operating lines, and the associated common pulleys c·an
`be made open and clear, free for new uses. The counter(cid:173)
`weight loading gallery is also eliminated, and the pro(cid:173)
`cedure of balancing the weight -of the set with coiinler-
`40 weights
`is also elfminated. Electrically coordinated
`motor-driven winches are used that are individual to each
`line; and there is flo longer any need for lines extending
`inflexibly from respective pulleys in the gridiron toward
`the common pulleys, nor is there any arbitrarily iitn-
`45 ited number of lines that may be operated in unison.
`The invention makes it possible for any line to extend
`in any convenient direction to any available winch. A
`related feature of the invention resides in the provision of
`supports .for individual sheaves virtually anywhere that
`50 may be desired, without the restriction heretofore of re(cid:173)
`quiring individual pulleys of a group of lines to be nicely
`in line across the stage.
`Further features of the invention reside in the provi(cid:173)
`sion of rows of fumly supported electric-motor driven
`55 winches at any convenient locations above the flies, as
`for example spaced along the rear .of the stage or anife
`side of the stage or across the front of the stage, -ot ·at
`all such.places. No longer it is necessary for all <if the
`lines from a given piece of scenery to extend· all the way
`60 across the stage to a colilDiofl pulley. With the present
`system, each line can extend to the nearest convenient
`accessible motor-driven winch. Each line need be ·no
`longer than necessary to reach the closest available
`winch. With the new system a line from a scenery ele-
`65 ment near the center of the stage· can extend to a ·winch
`at the rear, and lines from the sat-ne scenery element
`that 'are near the sides of the stage can extend to winches
`at the sides of the stage, all of the winches for handling
`a stage set being coordinated electrically.
`With the novel system it will be apparent that the lines
`extending upward from the scenery to pulleys or sheaves
`will nsually extend from those sheaves in 'various dkec-
`
`Page 9 of 18
`
`

`
`2,942,879
`
`55
`
`3
`tions toward the motor driven winches disposed about
`the stage, above the flies. As will be seen from the
`detailed description below of the illustrative embodiment
`of the invention, any desired number of winches can be
`coordinated and are effective to share the weight of a
`set during raising and lowering operations. Further,
`lines can extend upward from any Tiastening point on a
`stage set, whether it be fiat or complicated so as·to extend
`.both across the stage and having prominent front-to-back
`depth:
`Additional features of the invention relate to the elec(cid:173)
`jrical controls provided. These include provision for
`,automatically limiting the extent of raising and lowering
`pf the various sets, as well as for reducing speed as
`.each limit is approached, while maintaining proper co(cid:173)
`·ordination of the winches; in the selection of each group
`·Of winches; and the provision of means for concurrent
`operation of two groups of winches for simultaneously
`.!l'aising one stage set and lowering another.
`The foregoing objects and features of the invention
`are accomplished in the illustrative embodiment de(cid:173)
`scribed in detail beiow.
`In this embodiment, briefly, a
`series of winches are provided for the individual lines
`extending to sets or units of scenery. The lines for
`bandling each set extend to physically
`independent
`winches which are electrically coordinated. Each winch
`handles-one line. Each winch is driven by an individual
`electric motor. The control apparatus enables any com(cid:173)
`bination of winches that may be identified with a par(cid:173)
`ticular set to be connected for common control and
`. _energization. Two controlled power sources are pro-
`. vided and selective controls enable each source to be
`switched to each successive group of motors while the
`. other source is applied to any other selected group of
`-motors for concurrent operation but separately controlled
`. as to speed and direction.
`A feature promoting sustained coordination resides in
`. the use of synchronous type motors for the winches,
`and controlled-frequency sources of alternating current
`. for speed control of all winches operating a unit of
`scenery. Electric motors of other types capable of shar(cid:173)
`. ing the load of a set can alternatively be used in applying
`·certain broader aspects of the invention.
`As a detail of specific importance, the winches are
`·ideally of a form where the length of line taken in or
`paid out per motor rotation is constant, and where the
`. point at which the line reaches its winch is constant,
`. so .that, with equal motor rotations and uniform han- ·
`dling of the several lines of a set, initially established
`sharing of the load is maintained.
`With the foregoing background, the features of the
`illustrative embodiment described below will be readily
`. appreciated, and from this description additional objects
`·:and featur.es of novelty will become apparent.. The illus(cid:173)
`trative embodiment of the invention is shown in the
`.accompanying drawings forming part of this disclosure.
`. In the drawings:
`Fig. 1 is the cross section of a portion of a theatre ·
`showing the stage thereof, to which the invention .is
`_applied;
`_
`Fig. 2 is a vertical fragmentary cross-section along the
`line 2-,-2 in Fig. 1, drawn to a larger scale;
`Fig. 3 is a plan- view of the structure in Fig. 2;
`Fig. 4 is the side elevation of a typical novel winch
`:and related structure shown in Figs. 1 to 3, Fig. 4 being
`drawn to larger scale;
`Fig. 5 is an elevation of the winch in Fig. 4 viewed
`from the right thereof;
`Fig. 6 is a top plan view of the winch in Figs. 4 and 5;
`Fig. 7 is a fragmenttary transverse cross-section along
`the line 7-7 in Fig. 5;
`Fig. 8 is an enlarged detail of the sheave and sheave
`support in Fig. 4, the section being taken along the line
`.
`.
`_~8inFig.4;
`
`4
`Figs. 9a, 9b and 9c are the wiring diagram for control
`and coordination of a system ·of winches illustrated in
`the other drawings; and
`Fig. 10 is an elevation of conventional scenery handling
`5 apparatus view as per Fig. 2.
`Referring first to Fig. 10 there appear certain typical
`elements of conventional scenery-handling apparatus,
`supplementing the brief description above. Such appa(cid:173)
`~ratus is widely used and has been in use for several
`10 centuries.
`(The numel'als used here are primed nu(cid:173)
`merals corersponding to those used in the description of
`apparatus in Figs. ·1 to 9 which follows.)
`In Fig. 10
`the stage 10' has a fiat 24' carried by lines 26' which
`extend over pulleys 29' carried by the grid 32'. All
`15 of the lines 26' extending from a single scenery unit 24;
`. extend to a common pulley 20' and from this pulley to
`a common counterweight 19 which counterbalances the
`entire load of the scenery unit 24'. Puiley 20' is suit(cid:173)
`ably supported from wall 22', this wall extending down
`20 to the stage, or to a point close to stage leveL Wail
`22' additionally carries a gallery 21 close to the grid
`level, where a supply of counterweights is stored and
`where the sets, when being installed, are counterbalanced.
`Weights ·are added to the group of lines 26' until the
`25 scenery unit is •accurately counterbalanced. Thereafter,
`the weights are lowered and the set is elevated, or the
`converse, by means of an additional line 27 which rotates
`pulley 20' in either desired direction.
`The individual pulleys 29' guiding the group of lines
`30 26' are distributed along a line directly across the stage,
`that is, parallel to the front of the stage.
`It therefore
`·becomes necessary to provide scenery of such design that
`can ·be supported by this arrangement of lines. Each
`common pulley 20' can accommodate four lines, so that
`35 no more •than this number of lines can be used for an
`individual set, regardless of its shape, size or weight.
`Pulleys 29' are supported on rails extending front-to(cid:173)
`rear above the stage at a wide separation, which is a
`It
`further limitation on ,the usefulness of the system.
`40 is feasible to ·adjust the position of each pulley 29' per(cid:173)
`pendicular to the view, toward and away from the front
`of the stage; but all of the pulleys together with pulley
`20' are required to be adjusted so as to remain in line.
`In view of the requirement that all of the lines 16' at-
`45 tached to a given fiat 24' shall move together, they must
`all be operated by the same pulley 20' and therefore, if
`a single stage set extends all the way across the stage,
`the line to the most distant part of the scenery must
`also extend all the way across the stage, from the most
`50 remote vertical line to the pulley 20'.
`The common pulleys, counterweights and operating
`lines, being located only at the side of the stage, preempt
`·the· space there which might be used for other purposes .
`The walls 22' also support the weight-loading gallery 21.
`The grid 32' must be strengthened as by tie rods 33
`extending to the high iron 18' to support the pulleys 29'
`and the scenery load .
`This brief description of the typical standard apparatus
`for handling stage scenery can be extended for .better
`60 appreciation of what is involved by reference to standard
`. works on this subject as for example, that by Cole, Burris(cid:173)
`Meyer entitled. "Scenery for the Theatre."
`Referring now to Figs. 1 to 3 inclusive, the stage 10 of
`a theatre is illustrated, having a front wall 12 in which
`65 there is formed a proscenium 14 through which perform(cid:173)
`ances are witnessed, and a rear wall 16. The roof of the
`stage is supported by so-called "high-iron" 18 being usual(cid:173)
`ly a number of parallel I beams extending from the front
`to the rear ofthe stage. A series of winches 20 are shown
`70 extending along the front and back walls of the stage,
`and also against side walls 22 (Fig. 2) depending a short
`distance from the high iron 18. One such side wall 22
`depends from the high· iron at each side of the stage,
`leaving the. space below these walls 2Z at both sides of
`75 t}le st~~e . com:pletely free ~n~ ~le~:r, This is the space
`
`Page 10 of 18
`
`

`
`fl,D42,876
`-
`5. . .
`. .
`.
`. .
`that heretofore has been occupied by the counterweights
`and by the operating lines '27 (Fig. 10). Further, no
`COlllltetweight loading is needed in the full application
`of the present invention.
`In Figs. 2 and 3, one element of scenery 24 is shown 5
`at stage level and another element 26 is shown raised
`into the flies. An additional stage prop 28 is shown
`carried by a single line extending to its particular winch.
`Seven of the winches in Figs. 2 and 3 are designated 20A,
`20B • . . 20G. Winches 20A, 20C and 20E are con- 10
`nected by respective lines to the set or scenery unit 24
`whereas Winches 20B, 20D arid 20G have lines extending
`to The raised set 26. Winch 20F extends to scenery ele-
`ment 28.
`·
`Certain of the winches on wall 22 are seen in Fig. 3 liS
`to have lines extending to scenery, and these winches are
`located approximately where the common pulleys of con(cid:173)
`ventional apparatus previously were supported; but other
`winches designated 20A through 20F are shown carried
`by the rear wall, an area previously ignored insofar as 20
`the scenery handling apparatus is concerned. With the
`present arrangement as shown, evidently comparatively
`short lines can be used (insofar as their horizontal extent
`is concerned). If the line 26 extending from the winch
`20E to a point above scenery element. 24 is considered, 25
`its length is obviously much shorter than would be needed
`if that line were required to extend all the way to a
`cotnmon pulley at the side wall 22. The difficulties aris(cid:173)
`ing under previous practice become much more serious
`when it is considered that the right hand extremity of 30
`each element of scenery, omitted from Figs. 2 and 3
`might very well extend all the way across the stage.
`The lines extending from the winches 20 extend hori(cid:173)
`zontally (at a small incline) to respective sheaves 29
`which are carried by members 30, conveniently formed 35
`of steel, T-shaped in cross section. Members 30 are
`either directly secured to the high iron 18 or are carried
`by frame members 32 which in turn are carried by the
`high iron.
`The gridiron 32 is provided in the present illustrative 40
`embodiment of the invention at some distance below the
`high iron. This gridiron provides a platform over which
`personnel can walk in setting up the sheaves 29 and the
`various lines from the winches to the scenery units below.
`The gridiron has a number of channels forming passages 45
`34 between which the lines can freely extend, the remain(cid:173)
`der Of the gridiron ·furnishing walking area. Passages 34
`extend from the front to the rear of the stage, in the
`illustrative embodiment. These need not be made very
`close to each other as, for example, at 4-foot intervals.
`As will be understood from the detailed discussion of
`the Wiring diagram, the various winches having lines to
`individual scenery units are electrically coordinated and
`they function in exactly the same way as the common
`pulleys and counterweights that previously were utilized 55
`for handling a scenery unit. However numerous advan(cid:173)
`tages flow from the use of independent motor drives
`illustrated. Previously no more than four lines (as a
`ptactioal limit) could be handled by any one pulley and
`counterweight unit. Consequently a large or heavy ele- 60
`ment of scenery, or one which has a very great extent
`across the stage, might have to be subdivided so as to
`be separately handled and operated by two or more
`separate pulley-and-counterweight complements.
`In the
`present instance •as many v,inches and lines as may be 611
`considered appropriate can be assigned to any one ele(cid:173)
`ment or related elements of scenery. It is entirely feas(cid:173)
`ible .to operate multiple separate elements of scenery form(cid:173)
`ing part of a single set by coordinated winches. Thus, 70
`element 28 which is part of the lowered set can be
`raised and lowered by its winch 20F, which winch can
`be electrically coordinated w:ith the three winches 20A,
`20C and 20E having lines to the ·scenery unit 24 that is
`il~- lowered at stage level. In this way, any selected and 715
`
`... , , .
`·a
`coordinated group of scenery elements sloted ih the ffies
`above the stage can be lowered to stage level with a
`single control and in a single quick . powered operation.
`All those elements of the set can likewise be removed
`to ihe flies simultaneously. This system makes possible
`high speed of change, which can be of critical impor-
`tance in preserving -the mood . and timing in some dra•
`matic performances. Comparable speed could hardly be
`realized with the previous standard scenery-handling ap(cid:173)
`paratUs.
`The winches, the high i~on, the sheaves 29 and the
`sheave supports 30 'are shown in greater detail in Fi,gS.
`4 to 8 inclusive.
`In Figs. 4 and 8 the high iron 18
`carries the parallel elements 30 of T -shaped cross-section
`extending :along lines front-to-rear of the stage, ·and this
`:in turn supports sheaves 29. A series of holes 30a are
`formed in members 30 at convenient intervals, every
`three inches for example. . In this way a sheave can be
`located at any position required by the contour of the
`scenery, ·and the different sheaves having lines extending
`to different parts of the scenery can be located at differ-
`ent distances from the ·rear of the stage. This featUre
`is of particular impo!11:ance to aecommodate deep sets, of
`relatively complicated configuration, or sets that •are re(cid:173)
`quired to extend slantwise across part of the stage.
`The sheave 29 is carried by a U-shaped bracket 3'1
`(Fig. 8) which has holes in its side walls, through which
`spring pressed pins 36 extend. These pins may be with•
`drawn from the holes in members 30 by grasping knobs
`36a forming part of these pins. Springs 36b bias the
`pins to the right in Fig. 8 so that when released, pins 36
`project through the holes 30a in the sheave-suppomng
`members 30. Thus each ·sheave 29 can readily be lo(cid:173)
`cated •at any point above the stage, front-to-rear, that
`may be convenient or required.
`U-shaped member 34 has ·a bearing 38 that allows the
`pulley 40 to ro-tate ·about oa vertical axis. This is desir(cid:173)
`able when it is considered that ·a line from a sheave to a
`\vinch frequently extends at an angle to the front-to•back
`extent of member 30 over the stage (see Fig. 3 for ex-.
`ample).
`The winch itself is shown in elevation in Figs. 4 to 7.
`The winch is carried by a pair of fixed brackets 42 on a
`wall or other suitable support and by a movable frame
`44 that is movable on axially aligned pivots 46, conven(cid:173)
`iently shock-mounted, allowing the frame 44 to swing
`about a vertical axis. This swinging enables a guide pul(cid:173)
`ley 48 carried by the frame 44 to move into alignment
`with the sheave 29 to which the set-supporting line 26
`50 extends.
`A threaded beming or nut 50 is carried by frame 44 at
`its lower extremity and at rthe upper extremity there is
`a motor 52 which, through a worm 54 and a ·worm wheel
`56 (Fig. 5) drives shaft 58. The upper portion of shaft
`58 is splined and the bottom of it is seen to be threaded.
`Worm wheel 56 is restricted against vertical shift by
`fixed bearing plates 44a.
`In this way; as ·the motor ro(cid:173)
`tates shaft 58 •through the worm drive described, the
`lower portion of shaft 58, in rotating in threaded hearing
`50, is also forced to travel up and down axially. Shaft
`58 carries a drum 60 which has a helical groove· in it,
`of the same pitch or number of threads per inch as the
`lower po.ction of shaft 58 and consequently druin 60
`travels up and down in relation to guide pulley 48 at
`the same rate that the line-receiving grooves on· drum 60
`travel. Worm wheel 56 has passages allowing ·the splined
`portion of shaft 58 to slide up and down in relation to
`it (portions 4Sa preventing axial travel of the worm
`wheel 56 in relation to the worm drive 54).
`In addition to motor 52, bracket 44 also supports a
`transmitter synchro 62 having a sprocket 64, and chirln
`66 to couple it by sprocket 68 .to shaft 58. Bearing plate
`44b prevents shift of sprocket 68 away from upper bear(cid:173)
`ing plate 44a. In this way, synchro 62 generates a: sig(cid:173)
`nal whiCh is transmitted to a receiver synchro (deSCribed
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`Page 11 of 18
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`2,942,879
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`later)to indicate the rotational position of shaft 58 and,
`accordingly the axial position of drum 60.
`- The mechanical operation of the .winch in Figs. 4 to 7
`may be .readily.understood. When tension is developed
`in llile 26 extending from sheave 29 to guide pulley 48
`o( the winch, that guide pulley is lined up with the
`sheave. If the selected winch is not in line with T -shaped
`!!heave hang~r 30, _frame 44 of the winch swings about its
`pivot 46 so as to bring pulley 48 into alignment w1th its
`sheave 29.
`(Before line 26 is tensioned, pressure roll
`61, shown in Fig. 7 prevents loosening of the line). Op(cid:173)
`eration· of motor 52 rotates shaft 58 through .the worm
`dnve. 5~56; and line 26 winds or unwinds, depending
`u.Pon the direction of motor drive. Drum 60 is grad(cid:173)
`ually raised or lowered by the threaded lower portion of
`shaft 58 operating in threaded bearing 50, in order that
`the. grooves of drum 60 wili be in proper relation to re(cid:173)
`ceive or pay off <the iine 26. The provision of the ·worm
`drive is ·important, in . that this drive prevents tension in
`iine 26 ;from rotating shaft 58, that is, the worm drive
`is self-locking :and is not capabie of mechanically re(cid:173)
`versed operation. Rotation of the worm wheel 56 can(cid:173)
`nottake place in a way to drive the worm 54. This
`~voini drive 54-56 is in one-way drive in the sense that
`mechanically ihe member 54 is always ·the drive member
`and member 56 is the driven member. In this way, the
`weight of rthe set carried by line 26 is ineffective to drive
`the worm gearing in reverse so that, when motor 52 is
`idle, the position. of the set is fixed. The term one-way
`mechanical drive is used in referring to the driving mem(cid:173)
`ber_ in relation to ·the driven member, and not to the
`- rotational sense. Motor 52 is of a type to be electrically
`!"eversible for dther rotational direction, for winding up
`or paying off a desired length of line 26.
`In the course of reeling in or paying out some of
`line 26, ·because drum 60 moves to maintain a common
`:winding point at guide· wheel 48, the distance from the
`' winding point of the winch to the sheave 29 is constant.
`Itwill also berecalled that the vertical portions of lines
`~6 are parallel and are moved in equal increments by
`the coordinated winches. Hence all of the winches main(cid:173)
`tain their respective shares of the set load regardless of
`vertical position of the set and regardless of the random
`angles (note Fig. 3) that may result in the choices of
`winches for each set.
`Drum 60 may, for example, be of four-inch diameter
`_and 12 inches ~ong, with close-spaced grooves for re(cid:173)
`ceiving Vs diameter steel cable. Such a drum can store
`90 feet of cable.
`Synchronous electric motors 52 for the various winches
`are operated and coordinated by remote control, from a
`console at a- convenient location, preferably at a point
`£rom which full view of the stage may be had. The
`wiring diagram of that portion of the illustrative system
`that is. installed aJoft with the winches is shown in Fig.
`9a; the wiring diagram of the console is in Fig. 9b; and
`the 'wiring diagram of the power supply and its associ(cid:173)
`ated controls appears in Fig. 9c.
`· .. The system includes two separate sources of power,
`so that it is entirely feasible to raise one set and simul(cid:173)
`taneously lower another set, each at its own rate and
`each stopping independently, as required. This feature
`is hiihJ.y desirably in dramatic situations where quick
`change of sets is all-important.
`.- . Iil. Fig. 9a, rune winches 20 are shown, with a suit(cid:173)
`able number of these including transmitter synchros 62
`and the others, labeled 20a, lacking these synchros.
`Each motor 52 is connected by a first relay 80 to power
`liries 82 that are connected to a controllable alternator
`84. (Fig. 9c) suitably located in a· sub-stage installation,
`for example. Motors 52 can, alternatively, be connected
`by respective relays 86 to the power lines 83 from an(cid:173)
`other .:remotely located alternator 90. A common me(cid:173)
`~hanica}· drive ·motor 92 operates· alternators 84 and· 90
`~ough electrodynamically ·controlled drive· couplings,
`
`8
`94 and 96, respectively. This form of drive, the dynamic
`couplings 94 and 96, may be compared to a clutch which
`may be either effectively disengaged· so . as not to drive
`Its generator at all, or it may not . slip at all so as to
`lS drive-its generator at the full speed of motor 92 or the
`dynamic coupling may "slip" controllably, to provide any
`desired rate· between dead stop and full motor speecl.,:
`The speed of the alternator determines the frequency of
`its output and this determines the speed of each synchro-
`10 nous motor· 52 connected to it. Dynamic couplings• 94
`and 96 have their control devices 98 and 100. These
`dynamic couplings and their controls are well known ,and·
`their details, forming no part of. this invention; are not
`herein described.
`In one form, the dynamic coupling,
`15 may· be an eddy current clutch whose control gradually
`increases the eddy current field to increase the tightness
`of coupling. Thyratrons with adjustable grid-bias cir(cid:173)
`cuits are useful to control the eddy current-
`Each dynamic coupling control unit 98 and 100 has
`20 a control wire 102, which wires may be joined together.
`Unit 98 has a maximum 'speed connection 104 and a
`ininimum s:Peed connection 106, whereas dynamic cou(cid:173)
`pling control unit 100 has its maximum control wire
`108 and its minimum speed control 110. A potentiome-
`25 ter.112 (Fig. 9b) is provided which enables manual se(cid:173)
`lection of any desired speed between minimum and maxi(cid:173)
`mum of 'generator 84 and similarly a potentiometer 114
`is ·provided for enabling adjustment of the speed of op(cid:173)
`eration of generator 90 to any value between its mini-
`30 mum and maximum speeds as controlled by wires 108
`and 110.
`Each alternator 84 and 90 can be. connected to its re(cid:173)
`spective power lines 82 and 88 for operating the winch
`motors 52 in either :rotational direction. This depends
`35 upon the phase rotation of the motor, in relation to the
`connections of the generator to· the line. Either phase
`relationship can be established by selecting the appropri(cid:173)
`ate motor starter 116 or 118. · Motors 52 are all phased
`for like rotation when connected to lines 82. Starter
`40 116 may be phased to connect the alternator 84 to lines
`82 for craising the sets, and starter 118 is then oppositely
`phased. to connect alternator 84 to lines 82 for. lowering
`the sets. Each motor starter functions for all the motors
`conne