WO2010037384A1

WO2010037384A1 - A motorised spotlight and use thereof

Info

Publication number: WO2010037384A1
Application number: PCT/DK2008/000340
Authority: WO
Inventors: Thomas Brockmann; Peter I. W. Plesner; Christian Poulsen; Søren Sterndorff PEGLAU
Original assignee: Brother, Brother & Sons Aps
Priority date: 2008-10-01
Filing date: 2008-10-01
Publication date: 2010-04-08

Abstract

The invention relates a motorised spotlight (1) for stage use. The spotlight (1) comprises an outer gimbal (2) comprising mounting means (5) for rigidly fixating the motorised spotlight (1) to an installation surface (18), such as a ceiling of a stage, an inner gimbal (3) being double-sided suspended in the outer gimbal (2), and a spotlight housing (4) comprising at least one light emitting source (6), wherein the spotlight housing (4) is double-sided suspended in the inner gimbal (3). The invention further relates to use of a motorised spotlight (1).

Description

A MOTORISED SPOTLIGHT AND USE THEREOF

Background of the invention

The invention relates to a motorised spotlight for stage use and use thereof.

Description of the Related Art

It is well known in the art of stage performance to make one or more spotlights follow the performer around the stage during the performance. Previously these follow spots were manually operated but in recent years it has become common to operate these follow spots by means of motors such as step motors or servomotors.

Motorised spots are therefore known in the art and e.g. from American patent application No. US 2008/0062692 Al it is known to suspend a spotlight in a U- shaped bracket allowing that the spotlight can rotate around a first axis extending substantially between, the ends of the U and then rotatably mount the U-shaped bracket on a base so the bracket can rotate around a second axis, wherein the second axis is substantially perpendicular to the first axis and so that the second axis is substantially perpendicular to the base at all times. The rotation around the first and second axis is motorised and when the base is mounted on the ceiling with the ends of the U-shaped bracket facing down the spot can be directed at any point below the spot.

However such a spotlight is often mounted directly above the stage - on which the activity the spotlight is to follow occurs - and when the activity takes place around a point directly below the spotlight, the U-shaped bracket will have to rotate much both straining the motors, increasing the spotlights reaction time and reducing the spotlights operational speed. Furthermore if the spotlight is used for projecting an image onto the stage this image will be rotated considerably when the direction of the spotlight change and particularly if this image is not rotational symmetric, if the image generating means in the spotlight do comprise spotlight rotation compensating means of if these spotlight rotation compensating means are only capable of compensating a limited rotation of the spotlight this is highly disadvantageous.

An object of the invention is therefore to provide for a motorized spotlight which does not present the above mentioned disadvantages.

Especially it is an object of the invention to provide a motorized spotlight with an improved reaction time and improved operational speed.

The invention

The invention provides for a motorised spotlight for stage use. The spotlight comprises an outer gimbal comprising mounting means for rigidly fixating the motorised spotlight to an installation surface, such as a ceiling of a stage, an inner gimbal being double-sided suspended in the outer gimbal, and a spotlight housing comprising at least one light emitting source, wherein the spotlight housing is double-sided suspended in the inner gimbal.

Suspending the spotlight in a double-gimbal arrangement is advantageous in that it thereby is possible to direct the spotlight in any direction below the spotlight if it was mounted e.g. on a stage ceiling.

Furthermore, the double-gimbal arrangement - where both the inner gimbal in the outer gimbal and the spotlight housing in the inner gimbal is double-sided suspended - ensures that it only takes a minimum of movement of either of the gimbals to move the spot from one place to another. Even if the object the spot is following moves around immediately below a motorized spotlight mounted on e.g. a stage ceiling. This is advantageous in that it reduces wear of the moving parts of the motorized spotlight and it increases the acceleration and operational speed. Furthermore, if the spotlight is used for projecting an image onto the stage the reduced rotation will make it much easier to maintain the images orientation on the stage when the direction of the spotlight is changed.

Even further, by double-sided suspending both the inner gimbal in the outer gimbal and the spotlight housing in the inner gimbal it is possible to make the arrangement more rigid without increasing the weight thereby reducing the moment of inertia of the moving parts and enabling higher accelerations and higher operational speed.

An even further advantage of the present spotlight is that the movement of the light beam of the spotlight becomes intuitively related to the movement of a trackball or mouse used on the control system during position programming of a light show. This is advantageous in that the time needed for propamming is reduced dramatically.

It should be emphasised that by the term "installation surface" is to be understood any kind of surface on which the mounting means of the outer gimbal can be mounted no matter if the surface is straight, curved or other. The installation surface may be a ceiling of a stage or a stage set, the installation surface may be comprised by a lighting bar or a truss suspension system or the installation surface may in another way be a part of a scaffold, a stand, a support or any other kind of construction or object suitable for motorized stage spotlights.

In an aspect of the invention, said spotlight housing is suspended through pivotal joints located substantially at opposite sides of said spotlight housing and wherein said inner gimbal extends substantially continuously between said pivotal joints on both sides of said spotlight housing.

By rigidly connecting the pivotal joints on both sides of the spotlight housing a more rigid and strong construction is achieved which enables that the inner gimbal and the spotlight housing at a given power input can accelerate faster and accept a higher operational speed.

In an aspect of the invention, said inner gimbal is formed as a complete suspension ring enclosing said spotlight housing at least in a plane extending through a first pivotal axis, about which said inner gimbal pivots in relation to said outer gimbal, and a second pivotal axis about which said spotlight housing pivots in relation to said inner gimbal,

By forming the inner gimbal as a complete suspension ring a more rigid design is achieved which enables that the that the inner gimbal and the spotlight housing can be moved faster without jeopardising the stability of the spot.

In an aspect of the invention, said outer gimbal comprises a first gimbal arm and a second gimbal arm, wherein said inner gimbal is suspended between said first gimbal arm and said second gimbal arm.

Forming the outer gimbal as two arms extending on either sides of the inner gimbal is advantageous in that the movement of the spotlight housing will not be restricted by any form of transverse members connecting the pivotal joints below the joints i.e. on both sides of the joints. Likewise the light emitted from the spotlight will not be obstructed by such a transverse member in front of the spotlight.

In an aspect of the invention₅ said outer gimbal comprises a pivotal joint at an end area of said first gimbal arm and a pivotal joint at an end area of said second gimbal arm, wherein said inner gimbal is suspended through said pivotal joints.

Hereby is achieved an advantageous embodiment of the invention. In an aspect of the invention, said first gimbal arm and said second gimbal arm are rigidly connected by means of a transverse member.

Connecting the first gimbal arm and the second gimbal arm by means of a transverse member to form a bracket is advantageous in that hereby a more rigid design is achieved.

In an aspect of the invention, said transverse member comprises said mounting means for rigidly fixating said motorised spotlight to an installation surface.

Placing the mounting means on the transverse member is advantageous in that the transverse member is located central and peripheral to the entire spotlight and strain distribution-wise the transverse member is therefore an advantageous location.

In an aspect of the invention, said mounting means comprises one or more clearing holes.

Clearing holes are suited for accommodating screws and bolts and are therefore advantageous as mounting means for a motorized spotlight.

In an aspect of the invention, said spotlight housing further comprises a motor for pivoting said spotlight housing in relation to said inner gimbal.

Providing the spotlight housing - instead of the inner gimbal - with the motor for pivoting the spotlight housing in relation to the inner gimbal is advantageous in that both weight distribution-wise and for esthetical reasons the spotlight housing is a more optimal location for the motor.

In an aspect of the invention, said outer gimbal further comprises a motor for pivoting said inner gimbal in relation to said outer gimbal. Providing the outer gimbal - instead of the inner gimbal - with the motor for pivoting the inner gimbal in relation to the outer gimbal is advantageous in that hereby the motor can be place on a fixed part of the motorized spotlight, whereby power conduction through the pivotal j oints can be avoided.

Furthermore, by placing the motor on the fixed outer gimbal the weight of the pivotal inner gimbal can be reduced hereby enabling higher accelerations and operational speeds of the inner gimbal.

In an aspect of the invention, said spotlight housing further comprises focus means for making all the light emitted from said light emitting source exit said spotlight housing in substantially the same direction.

Providing the spotlight housing with focus means is advantageous in that it hereby is possible to ensure that the spotlight gives off a more concentrated spot.

Furthermore, the invention provides for use of a motorised spotlight according to any of the preceding claims, for illuminating a moving performer or object during a performance.

It is of course also advantageous that motorized spotlights for creating light shows, for creating visual effects or for projection images in relation with stage performances such as theatrical show or a musical concert can accelerate fast and have a high operational speed. But it is particularly important when the motorized spotlight acts as a follow spot that the spot can accelerate and move as fast as the object it is following and it is therefore particularly advantageous to use a motorized spotlight according to the present invention as a follow spot.

Figures The invention will be described in the following with reference to the figures in which

fig. IA illustrates a motorized spotlight, as seen from the front,

fig- IB illustrates a motorized spotlight, as seen from the side,

fig- 1C illustrates a motorized spotlight, as seen from the top,

fig. ID illustrates a motorized spotlight, as seen in perspective,

fig. 2 illustrates a motorized spotlight with the spot facing upwards, as seen from the front,

fig. 3 illustrates a motorized spotlight with the spotlight housing pivoted in one direction and the inner gimbal pivoted in another direction, as seen in perspective,

fig. 4A illustrates a motorized spotlight with an outer gimbal comprising a curved bracket, as seen from the front,

fig. 4B illustrates a motorized spotlight with an outer gimbal comprising a linear bracket, as seen from the front,

fig. 4C illustrates a motorized spotlight with an outer gimbal comprising two independent arms, as seen from the front, and fig. 5 illustrates a vertical cross section of a simplified motorized spotlight according to the present invention, as seen from the side.

Detailed description of related art

Fig. IA illustrates a motorized spotlight 1 as seen from the front.

In this embodiment of the invention the spotlight 1 comprise an outer gimbal 2 in the form of a bracket 14 comprising a first gimbal arm 10 and a second gimbal arm 11 extending down on either sides of an inner gimbal 3 suspending a spotlight housing 4.

The outer gimbal 2 is provided with a pivotal joint 7 at an end area 12 of the first gimbal arm 10 and a pivotal joint 7 at an end area 12 of the second gimbal arm 11 and by means of these pivotal joints 7 the inner gimbal 3 is double-sided suspended in the outer gimbal 2 and capable of pivoting around a first pivotal axis 8.

Fig. IB illustrates a motorized spotlight 1, as seen from the side.

In this embodiment of the invention the bracket 14 of the outeτ gimbal 2 is formed relatively slender and narrow in relation to the width of the spotlight housing 4 in order to save material, reduce cost and/or for esthetical reasons but in another embodiment the bracket 14 could be formed more massively e.g. to better accommodate a built-in motor 19 enabling that the inner gimbal 3 can be pivoted in relation to the outer gimbal 2.

In another embodiment the motor 19 - enabling that the inner gimbal 3 can be pivoted in relation to the outer gimbal 2 - could be mounted externally to one or both of the first gimbal arm 10 and/or the second gimbal arm 11 or both the first gimbal arm 10 and the second gimba] aim 11 could be fitted with an internally or externally placed motor 19.

Fig. 1C illustrates a motorized spotlight 1, as seen from the top.

In this embodiment of the invention the inner gimbal 3 is provided with pivotal joints 7 on either sides of the spotlight housing 4. By means of these pivotal joints 7 the spotlight housing 4 is double-sided suspended in the inner gimbal 2 and capable of pivoting around a second pivotal axis 9.

In this embodiment of the invention the inner gimbal 3 is formed as a closed suspension ring 15 extending substantially continuously between the pivotal joints 7 on both sides of the spotlight housing 4, in that the inner gimbal 3 is formed as a complete suspension ring 15 enclosing the spotlight housing 4.

hi another embodiment of the invention the inner gimbal 3 could also be formed by one or more brackets forming an open construction e.g. if a first fitting (not shown) was connecting only a first pivotal joint 7 between the outer gimbal 2 and the inner gimbal 3 with a first pivotal joint 7 between the inner gimbal 3 and the spotlight housing 4 and a further separate fitting (not shown) was connecting only a second pivotal joint 7 between the outer gimbal 2 and the inner gimbal 3 with a second pivotal joint 7 between the inner gimbal 3 and the spotlight housing 4.

Some or all of the pivotal joints 7 could e.g. be formed by fixed shafts or shaft-like arrangements suspended in bearings such as ball bearings, roller bearings, needle bearings, plain bearings or any combination thereof.

In practise the pivotal joints 7 could e.g. be formed by the inner gimbal 3 comprising fixed shafts extending outwards from either sides of the inner gimbal 3 into bearings located at the end area 12 of the gimbal arms 10, 11. Likewise the inner gimbal 3 could comprise a transverse shaft rigidly fixed to the suspension ring 15 and extending from one side of the ring 15 to the other side through the spotlight housing 4 (as illustrated in fig. 5). The spotlight housing 4 could then be provided with bearings through which the spotlight housing 4 was suspended on the transverse shaft, hereby allowing that the spotlight housing 4 may rotate on the shaft.

However, it should be emphasised that pivotal joints 4 can be made in a multitude of ways and the above mentioned embodiments are only examples on how the pivotal joints 7 could be designed. Many other designs are feasible.

Fig. 1 D illustrates a motorized spotlight 1 , as seen in perspective.

In this embodiment of the invention the gimbals 2, 3 with the pivotal joints 7 are arranged so that when the spotlight housing 4 is directed so that the light is emitted downwards in a direction directly opposite the mounting surface 16 of the outer gimbal 2, all four pivotal joints 7 define a plane which is substantially parallel with the mounting surface 16 and a installation surface 18 such as a stage ceiling.

In other words, the first pivotal axis 8 and the second pivotal axis 9 define a plane, which is parallel with the mounting surface 16 of the motorized spotlight 1 - and the installation surface 18 on which it is mounted - when the spot is directed in a direction opposite the mounting surface 16 i.e. when the spot is arranged perpendicularly on the mounting surface 16.

Fig. 2 illustrates a motorized spotlight 1 with the spot facing upwards, as seen from the front. In this embodiment of the invention the inner gimbal 3 suspending the spotlight housing 4 is moved to an extreme position in relation to the outer gimbal 2 and the spotlight housing 4 is turned slightly in relation to the inner gimbal 3.

In this embodiment of the invention the inner gimbal 3 can be pivoted approximately 135° in both directions in relation to the outer gimbal 2 from the position illustrated in fig. lA to ID.

In another embodiment of the invention the motorized spotlight design could entail that the rotational angle of the inner gimbal 3 in relation to the outer gimbal 2 could be further restricted e.g. only allowing the inner gimbal 3 to be pivoted 90° in both directions or the outer gimbal 2 could be designed to allow the inner gimbal 3 and spotlight housing 4 to be rotated a full 360° between the first and second gimbal arm 10, 11.

Fig. 3 illustrates a motorized spotlight 1 with the spotlight housing 4 pivoted in one direction and the inner gimbal 3 pivoted in another direction, as seen in perspective.

In this embodiment of the invention the mounting surface 16 of the motorized spotlight 1 is provided with mounting means 5 in the form of clearance holes suited for accommodating bolts or screws which can fixate the mounting surface 16 to the object or surface on which the spotlight 1 is to be mounted.

In another embodiment the mounting means 5 could comprise threaded holes, the mounting means 5 could comprise clamps or other equipment enabling that the spotlight could be mounted on a bar or a pole e.g. of a round shape or the mounting means 5 could comprise indentations, notches, projections or other surface iσegularities adapted for locking the spotlight to a mounting fitting or the like comprising corresponding surface irregularities. Fig. 4A illustrates a motorized spotlight 1 with an outer gimbal 2 comprising a curved bracket 14, as seen from the front.

In this embodiment of the invention the outer gimbal 2 comprise a semicircle shaped bracket 14. The bracket 14 comprise an end area 12 at each end of the bracket 14 where the pivotal joints 7 double-sided suspends the inner gimbal 3 and the end areas

12 are connected by a semi-annulus shaped transverse member 13. At the middle the transverse member 13 is provided with a fitting comprising the mounting surface 16 of the motorized spotlight 1 and mounting means 5 for fixating the spotlight 1 to an installation surface 18.

Fig. 4B illustrates a motorized spotlight 1 with an outer gimbal 2 comprising a linear bracket 14, as seen from the front.

In this embodiment of the invention the outer gimbal 2 comprise a bracket 14 formed by a straight first gimbal arm 10 and a straight second gimbal arm 11 extending downwards from a common transverse member 13 down to the pivotal joints 7 located at the end area 12 of the gimbal arms 10, 11.

Fig. 4C illustrates a motorized spotlight 1 with an outer gimbal 2 comprising two independent arms 10, 11, as seen from the front.

hi this embodiment of the invention the outer gimbal 2 is formed by a L-shaped first gimbal arm 10 and a L-shaped second gimbal arm 11. The two gimbal arms 10, 11 are completely separate from each other but when they are rigidly mounted on the same installation surface 18 they form part of a rigid outer gimbal 2.

Fig. 5 illustrates a vertical cross section of a simplified motorized spotlight 1 according to the present invention, as seen from the side. In this embodiment of the invention the inner gimbal 3 is connected to the spotlight housing 4 through ball bearings placed on either sides of the spotlight housing 4 to act as pivotal joints 7. To facilitate the rotation of the spotlight housing 4 in relation to the inner gimbal 3 the spotlight housing 4 is provided with an electrically powered motor 19 acting in the shaft, rigidly connected to the suspension ring 15, through a gear rigidly connected the shaft.

The motor 19 could e.g. be a step motoτ or a servo motor.

In this embodiment of the invention the spotlight housing 4 is further provided with a light emitting source 6 in the form of a incandescent light bulb placed inside a reflector acting as focus means 17 of the spotlight 1.

In another embodiment the focus means 17 could also comprise further reflective means and/or lenses and the light emitting source 6 could be one or more LEDs (light-emitting diode) or another type of light emitting device.

In this embodiment of the invention the emitted light leaves the spotlight housing 4 substantially unhindered but in another embodiment of the invention the spotlight housing 4 could further comprise beam modifying means for shaping the light beam, for using the beam to project an image or in another way modify the beam further.

These beam modifying means could e.g. be in the form of image slides, a Gobo, a masking or shutters which can enable that the spotlight 1 can project a specific image or that the light beam is shaped in a specific way such as a pattern. However, these beam modifying means are mounted in the spotlight housing 4 and therefore rotated with the housing. To compensate for this some systems are capable of counter- rotating inside the housing 4 to maintain the orientation or a projected image or pattern constant even if the spotlight housing 4 is rotating. However, it is evident that the known spotlight systems puts high demands on this counter-rotating mechanism and it is therefore advantageous if rotation of the spotlight is avoided or reduces when the direction of the spotlight is changed.

Furthermore, e.g. shutters - which are used for shaping the edges of the spotlight beam - are typically only capable of counter rotating approximately +/- 45°. In traditional spotlights 1 this is a problem because the spotlight housing typically rotates more than +/- 45° when operating above a stage.

The invention has been exemplified above with reference to specific examples of motorized spotlights 1, gimbal arrangements 2_} 3, 4 and other. However, it should be understood that the invention is not limited to the particular examples described above but may be designed and altered in a multitude of varieties within the scope of the invention as specified in the claims.

List

1. Motorised spotlight

2. Outer gimbal 3. Inner gimbal

4. Spotlight housing

5. Mounting means

6. Light emitting source

7. Pivotal joint 8. First pivotal axis

9. Second pivotal axis

10. First gimbal arm

11. Second gimbal aim

12. End area 13. Transverse member

14. Bracket

15. Suspension ring

16. Mounting surface

17. Focus means 18. Installation surface

19. Motor

Claims

1. A motorised spotlight (1) for stage use, said spotlight (1) comprising

an outer gimbal (2) comprising mounting means (5) for rigidly fixating said motorised spotlight (1) to an installation surface (18), such as a ceiling of a stage,

an inner gimbal (3) being double-sided suspended in said outer gimbal (2), and

a spotlight housing (4) comprising at least one light emitting source (6), wherein said spotlight housing (4) is double-sided suspended in said inner gimbal (3).

2. A motorised spotlight (1) according to claim 1, wherein said spotlight housing (4) is suspended through pivotal joints (7) located substantially at opposite sides of said spotlight housing (4) and wherein said inner gimbal (3) extends substantially continuously between said pivotal joints (7) on both sides of said spotlight housing (4).

3. A motorised spotlight (1) according to claim 1 or 2, wherein said inner gimbal (3) is formed as a complete suspension ring (15) enclosing said spotlight housing (4) at least in a plane extending through a first pivotal axis (8), about which said inner gimbal (3) pivots in relation to said outer gimbal (2), and a second pivotal axis (9) about which said spotlight housing (4) pivots in relation to said inner gimbal (3).

4. A motorised spotlight (1) according to any of the preceding claims, wherein said outer gimbal (2) comprises a first gimbal arm (10) and a second gimbal arm (11), wherein said inner gimbal (3) is suspended between said first gimbal arm (10) and said second gimbal arm (11).

5. A motorised spotlight (1) according to claim 4, wherein said outer gimbal (2) comprises a pivotal joint (7) at an end area (12) of said first gimbal arm (10) and a pivotal joint (7) at an end area (12) of said second gimbal arm (11), wherein said inner gimbal (3) is suspended through said pivotal joints (7).

6. A motorised spotlight (1) according to claim 4 or 5, wherein said first gimbal arm (10) and said second gimbal arm (11) are rigidly connected by means of a transverse member (13).

7. A motorised spotlight (1) according to claim 6, wherein said transverse member (13) comprises said mounting means (5) for rigidly fixating said motorised spotlight (1) to an installation surface (18).

8. A motorised spotlight (1) according to any of the preceding claims, wherein said mounting means (5) comprises one or more clearing holes.

9. A motorised spotlight (1) according to any of the preceding claims, wherein said spotlight housing (4) further comprises a motor (19) for pivoting said spotlight housing (4) in relation to said inner gimbal (3).

10. A motorised spotlight (1) according to any of the preceding claims, wherein said outer gimbal (2) further comprises a motor (19) for pivoting said inner gimbal (3) in relation to said outer gimbal (2).

11. A motorised spotlight (1) according to any of the preceding claims, wherein said spotlight housing (4) further comprises focus means (17) for making all the light emitted from said light emitting source (6) exit said spotlight housing (4) in substantially the same direction.

12. Use of a motorised spotlight (1) according to any of the preceding claims, for illuminating a moving performer or object during a performance.