CA1148928A - Winch system for raising and lowering sceneries on stage - Google Patents
Winch system for raising and lowering sceneries on stageInfo
- Publication number
- CA1148928A CA1148928A CA000373013A CA373013A CA1148928A CA 1148928 A CA1148928 A CA 1148928A CA 000373013 A CA000373013 A CA 000373013A CA 373013 A CA373013 A CA 373013A CA 1148928 A CA1148928 A CA 1148928A
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- winch drum
- motor
- winch
- section
- drum
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Abstract
ABSTRACT OF THE DISCLOSURE
A winch system for raising and lowering sceneries or similar loads on a stage is disclosed. The system comprises a series of support members adapted to be secured to the joists of a ceiling, an elongated winch drum made up of several sections interconnected by universal joints and supported in horizontal position by said support members, each winch drum section being provided over part of its length with a helical groove on which a cable for supporting the load is wound. Each support member carries bearing wheels engaging the helical grooves for rotatably supporting the winch drum and for causing its axial displacement at each turn by a distance equal to the pitch of the cable wound or unwound from the winch drum, such that the load will not be laterally shifted when being raised or lowered.
The shaft of a reversible hydraulic motor is secured to an end of the winch drum, whereby the hydraulic motor moves with the winch drum in its axial movement. The housing of the hydraulic motor is provided with a torque arm engaging a stationary guide extending parallel to the winch drum to prevent rotation of the motor housing. The hydraulic motor is controlled by a three-position spool valve, the position of which is controlled by a reversible electric stepping motor. Movement differential between the stepping motor and the winch drum produces progressive closing and opening of the valve which results in smooth acceleration and deceleration of the load during raising or lowering, and an accurate positioning of the load.
A brake is preferably provided to stop the winch drum when the hydraulic motor is not supplied with fluid under pressure.
A winch system for raising and lowering sceneries or similar loads on a stage is disclosed. The system comprises a series of support members adapted to be secured to the joists of a ceiling, an elongated winch drum made up of several sections interconnected by universal joints and supported in horizontal position by said support members, each winch drum section being provided over part of its length with a helical groove on which a cable for supporting the load is wound. Each support member carries bearing wheels engaging the helical grooves for rotatably supporting the winch drum and for causing its axial displacement at each turn by a distance equal to the pitch of the cable wound or unwound from the winch drum, such that the load will not be laterally shifted when being raised or lowered.
The shaft of a reversible hydraulic motor is secured to an end of the winch drum, whereby the hydraulic motor moves with the winch drum in its axial movement. The housing of the hydraulic motor is provided with a torque arm engaging a stationary guide extending parallel to the winch drum to prevent rotation of the motor housing. The hydraulic motor is controlled by a three-position spool valve, the position of which is controlled by a reversible electric stepping motor. Movement differential between the stepping motor and the winch drum produces progressive closing and opening of the valve which results in smooth acceleration and deceleration of the load during raising or lowering, and an accurate positioning of the load.
A brake is preferably provided to stop the winch drum when the hydraulic motor is not supplied with fluid under pressure.
Description
~8~Z8 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
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
- 2 -11~8~28 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 lC~ --3 ~
~ .
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.
- 3a -B
~8~28 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 - 3b -, ~8~Z8 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 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 _ 5 _ ~8~28 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 _ 6 -'~' ' 1~8~Z8 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 _ 7 _ -- :
~8~3Z8 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 B
1~8~Z8 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 _ g _ 1~ .
11~8~28 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~' B
- 9a -.
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 ~1~8~28 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 B
8~328 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 ~8~28 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.
~L9 - 13 -
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 lC~ --3 ~
~ .
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.
- 3a -B
~8~28 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 - 3b -, ~8~Z8 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 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 _ 5 _ ~8~28 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 _ 6 -'~' ' 1~8~Z8 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 _ 7 _ -- :
~8~3Z8 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 B
1~8~Z8 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 _ g _ 1~ .
11~8~28 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~' B
- 9a -.
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 ~1~8~28 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 B
8~328 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 ~8~28 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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Claims (16)
OR PRIVILEGE IS CLAIMED, ARE DEFINED AS FOLLOWS:
1. A winch system comprising:
a) a support;
b) an elongated winch drum upon which at least one cable supporting a scenery or similar load is wound, said winch drum being generally horizontally disposed;
c) bearing means secured to said support for rotatably mounting said winch drum end including means for longitudinally moving said winch drum at each turn by a distance equal to the pitch of the cable wound on, or unwound from, the winch drum;
d) a reversible winch drum driving motor for rotating said winch drum in anyone of the two directions; and e) means to control the operation of said winch drum driving motor including a control mechanism having a body and an operating member mounted in said body and movable between three positions, namely:
one limit position causing the motor to rotate in one direction;
a central position causing the motor to stop and another limit position causing said motor to rotate in the other direction, movement of said operating member relative to said body from said central position to one of the other of said limit positions, and vice versa, causing acceleration and deceleration of said winch drum driving motor, a controlling reversible motor having an output shaft, a control member responsive to and movable at a speed proportional to the speed of said output shaft and means responsive to the difference of movements of said control member and of said winch drum to move said operating member between its three positions relative to said body.
a) a support;
b) an elongated winch drum upon which at least one cable supporting a scenery or similar load is wound, said winch drum being generally horizontally disposed;
c) bearing means secured to said support for rotatably mounting said winch drum end including means for longitudinally moving said winch drum at each turn by a distance equal to the pitch of the cable wound on, or unwound from, the winch drum;
d) a reversible winch drum driving motor for rotating said winch drum in anyone of the two directions; and e) means to control the operation of said winch drum driving motor including a control mechanism having a body and an operating member mounted in said body and movable between three positions, namely:
one limit position causing the motor to rotate in one direction;
a central position causing the motor to stop and another limit position causing said motor to rotate in the other direction, movement of said operating member relative to said body from said central position to one of the other of said limit positions, and vice versa, causing acceleration and deceleration of said winch drum driving motor, a controlling reversible motor having an output shaft, a control member responsive to and movable at a speed proportional to the speed of said output shaft and means responsive to the difference of movements of said control member and of said winch drum to move said operating member between its three positions relative to said body.
2. A winch system as defined in claim 1, wherein said control member is movable by said controlling reversible motor in a path parallel to the longitudinal movement of said winch drum, said body being supported for movement at the speed of, and in the same direction as, the longitudinal movement of said winch drum and means connecting said control member to said operating member.
3. A winch system as defined in claim 1, wherein said control member is rotatable at a speed proportional to the speed of said output shaft and constitutes a first rotary means, and further including a second rotary means responsive to, and rotatable at, a speed proportional to the speed of rotation of said winch drum and said means responsive to the difference of movements of said control member and of said winch drum being means responsive to the difference of rotational movements of said first and second rotary means.
4. A winch system as defined in claim 1, wherein said winch drum driving motor is a reversible hydraulic motor having an output shaft connected to one end of said winch drum and having a motor housing longitudinally movable with said winch drum, means to prevent rotation of said motor housing as said motor rotates said winch drum in anyone of two directions, said control mechanism being a hydraulic spool valve, said body being the valve body and said operating member being the spool of the valve, said body fixedly supported with respect to said motor housing, said control member driven by said controlling reversible motor in a path substantially parallel to the longitudinal movement of said winch drum and said means responsive to the difference of movements of said control member and of said winch drum being responsive to the longitudinal movement of said control member parallel to said winch drum and to the longitudinal movement of said winch drum.
5. A winch system as defined in claim 4, wherein said controlling reversible motor is fixedly mounted on said support and its output shaft drives an endless screw arranged parallel to the long axis of said winch drum, said control member being a nut threaded on said screw, said spool being arranged parallel to the long axis of said winch drum and said nut secured to said spool.
6. A winch system as claimed in claim 4, wherein said control member is an endless screw mounted parallel to the long axis of said winch drum and mounted for longitudinal movement, an inwardly-threaded pulley screwed on said endless screw and driven in rotation at a stationary position by said controlling reversible motor, and further including means for transmitting the longitudinal movement of said endless screw to the spool of said valve.
7. A winch system comprising;
a) a pair of spaced supports;
b) an elongated winch drum upon which at least two cables supporting a scenery or similar load is wound, said winch drum being generally horizontally disposed;
c) a bearing assembly secured to each support for rotatably mounting said winch drum at two spaced zones longitudinally thereof, and including means for longitudinally moving said winch drum as the same is rotated at each turn by a distance equal to the pitch of the cables wound on, or unwound from, said winch drum;
d) a winch drum driving, reversible, hydraulic motor for rotating said winch drum in anyone of two directions, said motor having a motor housing and an output shaft, said output shaft directly con-nected to one end of said winch drum;
e) means to prevent rotation of said motor housing while allowing displacement of said motor housing along with said winch drum in its longitudinal movement; and f) means to control the operation of said winch drum driving motor including a hydraulic spool valve, hydraulically connected to said motor and having a valve body fixedly mounted relative to said winch drum driving motor housing and a spool mounted in said valve body and movable relative to said valve body between these positions, namely: one limit position causing the hydraulic motor to rotate in one direction; a central position causing the hydraulic motor to stop; and another limit position causing said motor to rotate in the other direction, movement of said spool relative to said valve body from said central position to one or the other of said limit positions, and vice versa, causing progressive acceleration and decelaration of said winch drum driving motor, a gear wheel mounted from free rotation at the outer end of said spool, two spaced parallel worms meshing with diametrically-opposite portions of said gear wheel and connected for rotation about their longitudinal axis fixedly with respect to said valve body, a controlling reversible motor driving one of said worms and trans-mission means causing rotation of the other worm by the rotation of said winch drum, whereby the difference in the rotational speeds of said two worms will cause movement of said spool longitudinally of said valve body.
a) a pair of spaced supports;
b) an elongated winch drum upon which at least two cables supporting a scenery or similar load is wound, said winch drum being generally horizontally disposed;
c) a bearing assembly secured to each support for rotatably mounting said winch drum at two spaced zones longitudinally thereof, and including means for longitudinally moving said winch drum as the same is rotated at each turn by a distance equal to the pitch of the cables wound on, or unwound from, said winch drum;
d) a winch drum driving, reversible, hydraulic motor for rotating said winch drum in anyone of two directions, said motor having a motor housing and an output shaft, said output shaft directly con-nected to one end of said winch drum;
e) means to prevent rotation of said motor housing while allowing displacement of said motor housing along with said winch drum in its longitudinal movement; and f) means to control the operation of said winch drum driving motor including a hydraulic spool valve, hydraulically connected to said motor and having a valve body fixedly mounted relative to said winch drum driving motor housing and a spool mounted in said valve body and movable relative to said valve body between these positions, namely: one limit position causing the hydraulic motor to rotate in one direction; a central position causing the hydraulic motor to stop; and another limit position causing said motor to rotate in the other direction, movement of said spool relative to said valve body from said central position to one or the other of said limit positions, and vice versa, causing progressive acceleration and decelaration of said winch drum driving motor, a gear wheel mounted from free rotation at the outer end of said spool, two spaced parallel worms meshing with diametrically-opposite portions of said gear wheel and connected for rotation about their longitudinal axis fixedly with respect to said valve body, a controlling reversible motor driving one of said worms and trans-mission means causing rotation of the other worm by the rotation of said winch drum, whereby the difference in the rotational speeds of said two worms will cause movement of said spool longitudinally of said valve body.
8. A winch system as defined in claim 7, wherein said valve body and said spool are arranged such that said spool is movable in a path parallel to the longitudinal movement of said winch drum, said worms being mounted for rotation about longitudinal axes parallel to the long axis of said winch drum and are mounted in a housing fixedly secured with respect to said motor housing, said controlling reversible motor being also fixedly secured with respect to said motor housing, gearing connecting said first worm to the output shaft of said controlling motor and said transmission means including gearing on said winch drum and on said second worm.
9, A winch system as claimed in claim 4 or 7, wherein said means to prevent rotation of said motor housing include a radial arm fixedly secured to said motor housing, a fixedly-supported channel extend-ing parallel to the long axis of said winch drum, said radial arm engaging said channel to prevent rotation of said motor housing, said arm longi-tudinally displaceable within and guided by said channel.
10. A winch system as defined in claim 1, wherein said winch drum driving motor is a reversible hydraulic motor having a flexible supply hose for hydraulic fluid under pressure, said hose being collapsible when no pressure exists therein, and further including a brake means responsive to the hydraulic pressure within said hose and connected to said winch drum and releasable when there is hydraulic pressure within said hose and effective to stop rotation of said winch drum when there is an absence of hydraulic pressure within said hose.
11. A winch system as defined in claim 1, wherein said winch drum comprises a driving section and at least one driven section joined in end-to-end relationship to the driving section by a universal joint, there being provided a cable for each section wound on a respect-ive section for supporting a scenery or other load, the outer surface of each winch drum section being provided with a helicel groove in which the wound portion of the cable is inserted, said driving motor being connected to said driving section to rotate said winch drum in either one of the two directions, said bearing means including two bearing assemblies spaced along said driving section for rotatably supporting said driving section at spaced zones along the length thereof and one bearing assembly for each driven section rotatably supporting said driven section at its end remote from its end fitted with said universal joint, each bearing assembly including a support and rollers carried by said support and engaging said grooves of the winch drum section at spaced points around the same and rotatably supporting said section, said rollers causing, upon rotation of said winch drum by said motor, longitudinal movement of said winch drum.
12. A winch system as claimed in claim 11, wherein said rollers are made of flexible and deformable material and are mounted for free rotation on axles arranged parallel to the longitudinal axis of the associated winch drum section, said rollers flexing as they rotate to engage said helical grooves.
13. A winch system as claimed in claim 11, wherein one end of said cable is attached to the winch drum section at a point remote from an associated bearing assembly and is wound on the winch drum section in the direction of said bearing assembly to issue from said winch drum at a point close to said bearing assembly.
14. A winch system as defined in claim 13, further including a collar rotatable around said winch drum section, said one end of said cable secured to said collar and means to adjustably secure said collar on said winch drum section to adjust the length of said cable wound on said winch drum section
15. A winch system as defined in claim 11, wherein said winch drum driving motor has a motor housing and a driving shaft, said driving shaft secured to an and of said winch drum to rotate said winch drum in either one of two directions, and further including a fixedly-supported guide means extending parallel to said winch drum and an arm secured to said motor housing, engaging and guided by said guide means in either one of two directions, while allowing its longi-tudinal movement together with said winch drum.
16. A winch system as claimed in claim 15, wherein said guide means is a channel rigidly secured to said support extending underneath said driving section and said arm-engages within said channel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/151,280 | 1980-05-19 | ||
| US06/151,280 US4324386A (en) | 1980-03-29 | 1980-05-19 | Battens system for raising and lowering sceneries or similar loads on a stage |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1148928A true CA1148928A (en) | 1983-06-28 |
Family
ID=22538055
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000373013A Expired CA1148928A (en) | 1980-05-19 | 1981-03-13 | Winch system for raising and lowering sceneries on stage |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1148928A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115414681A (en) * | 2022-08-12 | 2022-12-02 | 浙江大丰实业股份有限公司 | Stage curtain controlling means |
-
1981
- 1981-03-13 CA CA000373013A patent/CA1148928A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115414681A (en) * | 2022-08-12 | 2022-12-02 | 浙江大丰实业股份有限公司 | Stage curtain controlling means |
| CN115414681B (en) * | 2022-08-12 | 2024-08-09 | 浙江大丰实业股份有限公司 | Stage curtain controlling means |
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| MKEX | Expiry |