Note: Descriptions are shown in the official language in which they were submitted.
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FIELD OF T~E INVENTION
This invention relates to a winch system ~or raising and lowering
sceneries or similar loads on a stage.
KCROUHD OF TH~ INVENTION
Up to now, it has been 8 general practice to raise and lower
sceneries by means of cables passed through pulleys secured to roof joists
on the stage. The cables are generally passed through further pulleys down
to a control station where an operstor is located. In a complex play, it
is common to have~up to fifty winche~ which have to be operated at some
time during the play. This o~ten requires the attendance of several
operators, which increases ths cost o~ labor and also takes considerable
space along one wall of the ~tags. ~oreover,~due to the several counter-
weights and because the pulleys exert horizontal stresses on the roo~
~oists, the same often require strengthening.
OOJ~CTS OF INVENTION
It is therefore the object of the present lnventlon to provide
a system whlch can be easily operated by a single operator at a control desk,
which can be easlly automated, and the installation Or which does not
normally require strengthening of the roof-supporting joist~ above the
stage.
It is another object Or the lnvention to provide a winch system -
ln which the several winch drums, including thelr driving motor, are
horizontally disposed close together side by side for direct cable
connection with ths sceneries, and no floor space is needed on the stage.
Yet another object o~ the invention is to provide winch drums
which are easily installed and are suited for various stage widths, due
to the fact that each winch drum i8 composed of a plurality o~ modular
sections interconnected by universal joints.
Another ob;ect of the invention is to provide a winc~ system
3û in which each wlnch drum is arranged ~or rotaticn ~or direot winding
and unwinding of the load-supporting cables, while the winch drum moves
axially at each turn a distance equal to the pitch o~ ths cable wound
or unwound from the winch drum, 80 as to prevent lateral shifting o~ the
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load.
Another object of the pre~ent invention i8 to provide a ~inth
system of the character de~cribed, in which the rever~ible hydraulic motor
drlvirg the winch drum has its shaft directly secured to one end of the
wlnch drum, while the motor housing has a torque arm engageable with a
track means extending parallel to the winch drum, the arm preventing rotation
Or the motor housing.
Another obJect of the invention ie to provide a winch sysitem
Or the character described, including a slave mechanism for progre~siue
starting and stopping of the drive motor, 80 as to ~moothly accelerate and
decelerate the load and for exact positioning of the load.
SU~MARY OF INV~NTION
The winch Rystem oP the invention comprises a horizontally-dis-
posed elongated winch drum, preferably made of a driving section and at
least one driven section interconnected in snd-to-end relation by means of a
unlversal ~oint. Two spaced supports and bearing assemblles support the
driving section and one aupport and bearing assembly support each driuen
section. A cable is wound on each section for supporting a load. The
bearing asaemblies engage the`outer surrace Or the winch drum and cause
longitudinal movament Or the winch drum at éach rotational turn of the
winch drum by a distance equal to the pitch of the cable wound on,or unwound
from, the winch drum. A motor drives the winch drum in rotation in two
dir~ctions. Prererably the output shaft Or aaid motor is directly con-
nected to one end Or the driving aection, while a torque arm prevents the
motor housing from rotating,but allow~ longitudinal movement Or the same with the
winch drum. ~eans are provided to control the operation Or the driving motor
including a controlling motor and a feedback mechanism responsive to the
movement of the winch drum for progreesive acceleration snd deceleration of
the winch drum and accurate positioning Or the load. Prefersbly, the driving
motor is a hydraulic motor fed with hydraulic fluid by a flexible hose and
a braKing system responsive to the hydraullc fluid pressure exerted within
aaid hose ser~es to brake the winch drum against rotation whenever there 18
an abaence of hydraulic pressure within the hose. The cables ere wound
on the winch drum sections in a direction to issue from these sections cloae
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to the ~upports to auoid torsional stress on the support~.
EF DESCRIPTION OF DRAWINGS
The invention will now be disclosed by way of example with rsference
to the accompanying drawings, in which:
Figure 1 i~ a perspective view of part of the
in accordance with the invention;
Figure 2 is a side view of the winoh ~ystem 0f Figure l;
figure 3 is a cross-section taken along line 3-3 of Figure 2;
Figure 4 is a cross-section taken along line 4-4 of Figure 3;
Figure 5 is a cross-section taken along line 5-5 of figure 2;
Figure 6 is a schematic view of the hydraulic circuit of the
spool valve illustrated in Figure 2;
Figure 7 is a side view of the winch system in accordance
with the invention;
Figure 8 shows one driven modular section of the winch drum,
partly ln elevation and partly ln longitudinal section and ~hown connected
to an ad~acent end of the driving modular section;
Figure 9 ie a croE~s-section taken along line 9-9 of Figure ~;
Figure 10 is a section taken along line 10-10 of Figure 2;
Figure 11 is a side view, partly in longitudinal section, of
a winch system showing a modified slave mechanism.
Figure 12 is an enlarged side view of part of the slave
mechanism of Figure 11;
Figure 13 i9 a partial side view of a modified winoh system, also
showing another ambodiment of the slave mechanism;
Figure 14 is a cross-section taken along line 14-14 of Figure 13;
Figure 15 is an enlarged side elevation of the slave mechanism of
Figure 13;
Figure 16 i~ an end view of the slavs mechani~m of Figure 15
30 and showing the winch drum in section;
Figure 17 is a longitudinal section of part of the mechanism
shown in Figure 15; and
Figure 1~ is a cross-section taken along line 18-18 of Figure 17.
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In the drawings, like reference characters indicste like elemen~s .
throughout.
DETAILED DESCRIPTION OF INVENTION
The wlnch system of the invention compriseo an elongsted winch
drum 10, upon which is wound aneor more cables i2 supporting a scenery 14,
either directly or through a pulley 16. The winch drum 10 i8 made of a driving
tubular ssction 10' and o~ a plurality of driven tubular sections 10"
(see fig. 7) joined together by means of universal joints for easy instal-
lation, as will beccme
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more apparent hereinafter.
~ ach cable 12 i9 secured at one end to the winch drum 10 by
means, for instance, of a collar 13 in which the cable 12 is inserted
and which is rotatable about the winch drum, and can be secured in
adjusted position by means of a setscrew 13a. Each cable 12 i9 wound
in a continuous helical groove 18 located on the outside periphery
of the drum, as shown more clearly in Figures 2 and 4. The pitch o~
the helical groove 1~ thus determines the pitch of the cable being
wound or unwound from the drum. Flattening of cable 12 by the load
is prevented, because it is supported in groove 18 over an appreciable
portion of its periphery. The winch drum lû is rotatable in bearing
assemblies, each including a vertical support plate ?0 having an
aperture 21 through which the drum frsely extends. The support plate
20 is secured by screws 22 to a roof ~oist, or beam 24, near the
ceillng of the stage and three ~ets of roller bearings 26 are mounted
on plate 20 ~round the winch drum 10 and spaced at about 120. Eaoh
set of roller bearings includes two roller~ 28 (see Figure 10) mounted
on a shaft 30, one on each side of plate 20, with the shaft 30 inclined
with reapect to the plate, 80 as to be perpendicular to the groove
18 in accordance with its pitch. Each roller has a pair of peripheral
ribs 32 engaging spaced portions of the helical groove 18 of the winch
drum 10, 80 as to positively cause longitudinal movement of the winch
drum 10 at each turn of the latter by a distance exactly equal to
the pitch of the cable wound on the drum 10. More than three sets of
roller bearings 26 could be obviously used.
The winch drum is rotated in both directions by means of a
reversible hydraulic motor 34 having its output shaft 34a (see Figure 2)
secured to the er.d of the driving section 10' of the winch drum. Thus~
the entire motor, including the motor housing 34b, moves longitudinally
with the drum. The motor housing 34b is mounted on a plata 36 and
rotation of the plate and of the motor housing, due to the counter torque
exerted by the motor, is prevented by means of a radial arm 38, which
is secured to the plate 36, or integral therewith, and is provided
28
with a guide follol~er 40 (see Figures 2 and 5) engaging a guids 42
extending parallsl to winch drum 10 and secured to the adjacent roof
jOi~lt 24 by means of screws 44.
Preferably, a braking mechanism i~ provided for preventing
roteltion of the drum 10 under the weight'of the scenery 14~ or similar
loads attached to the cables 12 wound on the drum 10 when the pump
(not shown) ~upplying fluid under pressure to motor 34 is not working.
Such braking mechanism may include a disc 46 secured to, or integrsl
with, the drum 10 and brake shoes 48 mounted on plate 36. The brske
shoss are applied on the disc by spring means, not shown. An electro
magnet 50 serves to release the brake against the action of said spring
means.
Another type of braking msans operated by the hydraulic liquid
feeding tube of the motor 34 can be provided, as schematically shown 8~ 70 in
Figure 11 flnd as more clearly described in ~.S. Patent Hntitleds
"8RAKE", by the ~ame inventore, issued under Serial Number 4,271,934
dated November 16, 1980.
A strain gauge 52 may be provided on the arm 38, as shown in
Figure 5, for stopping motor 34 when the torque applied to the
latter is above or below a predetermined range.
As shown in Figures 7 to 9, the winch system is made of
modular sections, 80 as to be extended in accordance with the desired
length of the winch drum and each section connected to the other by means
of a universal joint for ease of installation on roof joists 24, which
often are not exactly at the same level. The driving section 10',
which carries the hydraulic motor 34, comprises a tube 11 at both ends
of which are welded grooved sleeves lla and llb of such a length that
the sleeves lla and llb are respectively directly'mounted above a support
joist 24 and with the re~pective grooved sleeve extending through
aperture 21 of 8upport plate 20 and its groove 18 engaged by the sets of
ribbed rollers 28, as previously described. Fach grooved sleeve carries
a cable 12 wound thereon as noted above. Thus, the driving section 10'
is supported near both ends by the two joists 24. The left-hand grooved
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aleeve llb, that ia the ~leeve opposite the end carrying the m~ or 34,
has a pair o~ diametrically-opposed notches llc.
All driven modular sections lû" are of eimilar construction and
each includes a tube lld having diemetrically-opposed radially
protruding studs lle at one end for remouebly engaging the notches llc
of the driving section or of another driven section. The driven section
further includes e grooved sleeve llf st its other end provided with
notches llc for receiving the studs of en adjacent driven section.
Therefore, each driven section hss one grooved ~leeve supported over
joist 24 by sets of ribbed rollers 2~ engaging the helical groove 1~ of
the section of the sleeve.
The notch and stud engagement permits rotation af the driven
sections by the driving section, while forming universal ~oints which
are ~imple in construction and allow for 00unting of sny desired length
of winch drum over roof ~oi~to 24 which might be at en uneven level.
Each driven ~ection and the drlving section are posltively moved
sxially of the winch dru~ n exect distence ee detsrmined by the similar
pitch of the helical groove~ 16 of the verious sections.
It is noted that the cables depend from the grooved ~leeves
adjecent the essociated support ~oists 24, 80 that the l~tter are submitted
only to vertical loading and not to torsion or to horizontal stress.
The raising ond lowering of the scenery is cDntrolled by a
positioning mech~nism arrsnged as ~ slave system. A first embodiment of
the po~itioning mechsnl~m i8 ehown in Figure 2 snd a ~econd embodiment 18
shown in Figure 11~ Referring to Figure 2, a spool vslve 54 has its body
54a directly secured to the motor housing 34b ~nd ia in direct communicet~on
with the ports o~ the motor. The spool value 54 has a spool 54b which is
vertically slidsble, as ehown in Figure~ 2 snd 6, to take three posltion~
namely; a neutral center position in which the two ports of the motor 34
are blocked; ~ lower posltion in which the motor rotstea ln one directlon~
and an upper position in whlch the motor rot~tes in the opposite direction
for raising and lowering the scenery 14, respectively. The vHlve 54
itself i9 of~conven~lonei construction, but it must be stationarily
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mounted with rs~pect to the motor 34, ~o as to move along with the winch
drum and the motor in the axial movement. A controlling member 60, in
the form o~ a rocker arm pivoted on ths valve body 54a and to the end
of the spool 54b, i8 pivotally connected to a threaded rod 58, which
extends parallel to winch drum 1~. A journal 61 for a pulley 62 is
secursd to support plate 20; pulley 62 i9 rotatably mounted on journal
61 and i8 in threaded engagement with the threaded rod 58 which extends
freely through journal 61. An electric rever~ible motor 64 i8 mounted
on a plate 66 (ses Figure 3) sscured to the support plate 20~ and has
its shaft coupled to pulley 62 by means of a belt 68. The hydraulic
motor 34 being ~topped, that i8 with the spool valve 54 in neutral central
position, raising or lowering of the scenery is accomplished by starting
electric motor 64 in the desired one o~ two directions, therefore
rotating pulley 62 which causes axial movemept of the threadsd rod 58
in a direction corresponding to the winding or unwinding of the csble.
The rùd 5B causes pivoting of rocklng arm 60 and dlsplscement o~ the
opool 54b~ 80 that the 8poOl v~lve admits ~luid under pressure to the
hydraulic motor in the desired direction to cause rotation or the winch
drum and, consequently, its axial movement in the sHme direction as the
movement of the threaded rod 58.
Since valve body 54a starts to move as soon as fluid is ted to
motor 34, there is obtained very progres~ive movement o~ the rocking arm
6û and, consequently, movement of the spool 54b which produces very
progressive opening of the ports in the spool valve to permit progressive
smooth acceleration o~ the motor 34. A8 soon as electric motor 64 is
stopped~ the rod 58 stop~ and the continuing rotation and consequent
axial displacement o~ the winch drum ~nd of the valve 54 causes rocking
o~ the rocking arm 6û and displacement of the 8pool 54b to its ~eutral
position. Here again~ a smooth deceleration to a stopping position is
3û obtained. As the winch drum moves axially at the same speed as the threa-
ded rod 58, there i8 no pivotal movement o~ the rocking arm 60 and the
spool of the valve remains in its stationary position. For manual
positioning of the scenery, electric motor 64 i~ a reversible, constsnt
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or variable spsed motor, remote-controllad by a manual switch operated
to raise and lower the scenery to the desired position. For automatic
positioning of the scenery, motor 64 is a rever~ible stepping motor which
can be programmed from a remote location to rotate its shaft a predetermined
numbel- of turns in either direction at a variable or at a constant speed
and then stops.
Figures 11 and 12 show another embodiment of the positioning mechanism.
Again, ths three-way spool valve 54~ i~ directly mountod on the motor hou~ing
34b and has its ports in direct communication with the two ports o~ the
motor housing. The spool 54~b is slidable horizonta~ly of the valve body
54'a between a central neutral position and tWD limit po~itions corresponding
to the winding and unwinding rotation of the winch drum, respectively. The
spool 54'b i8 tubular and is connected to a flexible liquid feeding tùbing
68', which also serves to operate a brake system 70 in a manner de3cribed
in the abov~-described Patent entitled: ~ORAKE". The other
end of tubular spool 54'b is connected to liquid return tubing 72. A
nut 74 18 secured to the tubular spool 541b and a threaded rod 76 is
threaded ln nut 74 and extends parallel to the winch drum 10 and conetitute~
the output shaft o~ an electric motor 78, which i8 directly mounted on~the
support plats 20 of the driving section 10'. Motor 78 i~ a reversible
motor which, as in the other embodiment, can have constant or a uariable spePd
and can be a manually-controlled or a stepping motor for automatic position-
ing of the scenery. The rod 76 just rotates and will move nut 74 in one
direction or in the other, controlling the operation of the spool valve
54' accordingly to cause rotation of the winch drum by the motor 34 in the
desired direction. Obviously,in both embodiments, the arrangement of the
ports and of the spool valve and the pitch of the threaded rod 50, or 76,
must be selected 80 that the controlling member will move in the appropriats
direction correspording to the axial movement of the winch drum correspond-
ing to the winding or unwinding of the scenery, respectively. The rocking
arm 60 of the first embodiment, or the nut 74 of the second embodiment,
constitutes a controlling member which is connected to the spool of the
ualve and which ie power driven to move linearly parallel to the linear
movement o~ the winch drum. When the wirch drum moves axially at the
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speed of the controlling member, the spool remains statlonary rs1ativo
to the valve body. When there is a differentisl in the speed, the
sppol change~ ita position rslative to the valve body. 8y properly
shoplng the ports in the valv- body snd in the spool~ if the latter
le tubular, as in the second embodiment, a very exact positioning
of the scenery can be obtained, a8 well as very smooth scceleration and
deceleration of the same.
When the motor 34 i~ energized to rotate the winch drum
in a direction such as to raise the w enery, the peripheral ribs 32
of the bearing rollers 28 engage the groov 18 in the winch drum, 80
that the drum is moved to the right st each turn by a distance equal
to the pitch of the cable, thuc preventing thé scenery balng shlfted to
right or le~t. The reveree will happen during lowerlng of the scenery,
and again the scsnery wlll not ehi-t lsterally. The preaaure and
flow r~te of the hydraulic fluld fed to hydraullc motor 34 ara
~elected ~o a~ to apply adequate torque to the w~nch drum to rai~e
the scenery or simllar load of maxlmu~ intended weight at a maxi~um
intended speed corresponding the full opening of the valvo ports.
The valve automatically partially closes, depending on a lesser load
and deeired vertical speed. In caee of overload, euch as when the
positioning mechanism falls and the motor 34 continue~ to rotate
when the scenery hae reached ite upper poeition, strain gauge 52 will
operate to de-energize the motor 64 or 78. Upon reversal of the
motor 34 to lower the scenery, the required torque will be that
needed to keep at the desired speed the lowering of scenery of a
given weight. Again, valve 54 or 54' automatically ad~u~t~ the flow
rate of fluid fed to motor 34. When the scenery hits the floor or
an obstacle, strain gauge 52 will again operate to stop controlling
motor 64 or 78 with practically immediate ~topping of hydraulic motor
3û 34.
Refsrring to ~igures 13 to 18, there is shown a modified winch
gystem and including a modified ~leeve meLhanism fDr controlling the
operation of the winch sy~tem. As in the other embodiment~, the driving
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ssction 10~ of ths winch drum 10 i8 supported at two spaced zones
by supports and bearing assembliss secursd to the roof joist 24.
Eaoh support plats 20 carri~s a set o~ rollers 2~'
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11~8~328
mounted on shafts 30' which are arranged parallel to the longitudinal
axi~ of the winch drum while the rDllers 28' are made of flexible material,
such as a p}astic material, ~o as to flex and be deformable in such a way
that their peripheral portion will engage the helical groove 1~ of the
winch drum sections, despite the fact that this groove is inclined to the
long axis of the ~haft. Preferably, there sre only two sets of rollers 2a'
engaging the helical groove 18 at 12û apart underneath the winch drum while
the support plate 20 is provided with a curved guard wire 31 ~pacedly
surrounding the top portion of the winch drum, as shown in Figure 14. The
driving section 10', as in the other embodiments,i~ driven in rotation
by a reversible hydraulic winch drum driving motor 34, the output sha~t
34a of which is directly secured to the outer end of the driving section
lO' and the motor housing 34b of which i8 prevented from rotation by means
of the radial arm 38 and guide follower 40 engaging the channel shaped
guide 42 secured to the support plate 20 and extending parallsl to the
long axi~ ot the wlnch drum 10. Thererore, the motor houoing 34b moves
along with the winch drum 10 in ito longitudinal movement. A hydraullc
spool valve 54 controls tha operation of the hydraulic motor S4. This
spool valve has a valve body 54", which is secured to the motor housing
34b by means of a bracket 80 and is oriented in such a wa~ that the spool
81 of the spool velve i8 arranged parallel to the long axis of the winch
drum, a8 in the other embodiment of Figure 11. The spool 81 has a central
position wherein it stops rotation Or the motor 34, one limit poaition
in which it drives the motor 34 in one direction and an opposite limit
position in which it drives motor 34 in the oppo~ite direction.
The ~pool 81 is prDvided at its outer forked end~ a~ shown in
Figure 17, with a gear wheel 82, which is mounted for free rotation abou~ -
a shaft 83 carried by the spool 81 and extending transversely Or the same.
The spool 81 extends and is longitudinally guided within a housing 84,
secured to bracket 80. Spool 81 and gear 82 are thus longitudinally
movable within~the housing 84 and rctation of the spool 81, together with gear
82, is prevented by guide rod~ 85, which extend on each side of the gear
82 aboue and below the spool and are fixed to the end walls of the housing
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84.
First and second worm~ 86 and 97, respectively, are rotatably
mounted within the housing 84 and extend parallel to the axis of the spool
81 above snd below the same, 80 as to mesh with diamstrically-opposed
portions of the gear 82.
The shaft of the flrst worm 86 is fitted with a driving gear
88 meshing with a pinion ~9 secured to the output shaft o~ a reversible
electric stepping motor 90 mounted on the housing 84. This electrlc
stepping motor 90 is the controlling motor. The second worm ~7 is
similarly fitted with a gear 91 meshing with 8 sscond gear 92 coaxial with
and secured to the outer end of the driving section 10' of the wlnch drum.
The ~lave mechanism further includes an indicating and monitoring
system to automatically stop operation of the winch drum driving motor wh~n-
ever there i8 failure in the system. To this end, a forked lever 93 engages
shaft 83 of gear 82 and is pivoted in the houging 84 by means of a shaft
94. An indicating arm 95 is fixed to the shaft 94 on the outside of
houslng B4, as shown ln Figures 15 and 18. This arm 95, when pivoted to
one or the other extreme limit positions, will hit on one or the other
limit switch 96 secured to the housing. These switches are connected
to an electric circuit to automatically stop the supply of hydraulic fluid
to the driving motor 34 in accordance with the spool having moved past
one or the other of its normal limit positions.
As in the embodiment of Figure ll, there is provided a braking
system 70 rasponsive to the flexibility of the hydraulic fluid feeding
hose or tubing 68l to poeitively brake the winch drum against rotation
whenever there is an sbsence of hydraulic fluid pre~sure within the hose
68'.
The sy~tem of this embodiment operates as follows:
It has thej~dvantage of sensing the much faster speed of rotation
of the winch drum instead of sensing its longitudinal movement. Therefore,
lt i~ more accurate than the previous embodiments ln the exact positioning
of the scenery or other load.
Supposing the winch drum i8 stopped with the spool 81 in its
central position, starting of the controlling electric stepping motor 90
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will cause rotation of the firYt worm 86 in one or the other direction
and, therefore, rotating the gear a2 which react3 against the stationary
second worm 87 to thereby cause mouement of the sponl 81 to one of it8
limLt po~itions to open the valve and feed the hydraulic fluid to the
hydraulic motor 34. As soon a9 the winch driving motor 34 starts, rotation
o~ the winch drum causes the rotation of the second worm 87 ln the same
direction, thereby slowing down the longitudinal movement of the spool; when
the two worms rotate at the same speed, the shaft ~3 af gear 82 remains
stationary, while the latter simply rotates. Therefore, stepping motor 9û
drives the winch drum at exactly the required speed. Upon stopping of the
controlling electric motor 90, the reverse operation takes place and
the spool i~ gradually brought back to i~s central position, resulting
in smooth deceleration of the rotation of the winch drum and its stopping
at the exact desired position.
This system is fail-~afe because, if the controlllng worm 86
grlps, the spool wlll automatlcally move to its central posltion~ thereby
stopplng the hydraullc motor 34. If the second worm 67, whloh i8 con-
trolled by the wlnch drum 10, stops to rotate for whatever reasons, ~uch
88 an obstruction on the load or gripping of the sscond worm, then the
spool ~1 will reach one or the other of its extreme limit positions,
causing actuation of one or the other limit switches 95 and thereby stop-
ping of the hydraulic driving motor.
, Finally, the system i8 fail-safe because the output, which is
the spool, cannot drLve the inputs represented by the worm~, since the gear
82 cannot drive these worms in rotation.
The above arrangement thus provides a po~ltlve stop of the
scenery or ~imilar load, which is safe to the people on the stage. The
above-disclosed wlnch system is a great improvement over the known system,
as it takes up m~ch less space on the stage, since no pulley~ end counter-
weights are required. With the prior art system, a full wall of the
~tage waa o~ten tsken as some stages had up to fifty winches. Wlth the
present arrangement, the wlnches are positlonéd above the ~tage, ona
beside the other, to operate a8 many sceneries as needed. The only
equipment on stage is a control desk. Also, since ~oi~ts or beams 24
are sub~ected to verticsl
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loading only, they will not normally require reinforcement for insta~-
lation of the winch sy~tsm. Each winch drum could obviou~ly operate
plural scenerie~ in synchronism located at predetermined distances
apart by providing additional cable~ wound on the same winch drum and
passlng such cablss through a system of pulleys secured to the ceillng
of'the stage.
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