EP1001212A2

EP1001212A2 - Position locking mechanism for an automated luminaire

Info

Publication number: EP1001212A2
Application number: EP99308982A
Authority: EP
Inventors: Derek Nash; John W. Ii Lane
Original assignee: High End Systems Inc
Current assignee: High End Systems Inc
Priority date: 1998-11-12
Filing date: 1999-11-11
Publication date: 2000-05-17
Also published as: EP1001212A3

Abstract

An automated lighting fixtures which automatically locks specific moving part(s) into fixed position(s) when power is not supplied to facilitate packaging, shipping, load-in and load-out of the fixtures.

Description

Field of the Invention

The present invention relates to lighting fixtures and specifically to a means of locking the moving parts of fixtures in a fixed position while the fixture is not in operation.

Background of the Invention

Automated lighting fixtures often include a means of controlling the position of the light beam projecting from the fixture by remote control. In some fixtures, the position of the light beam is controlled by a movable mirror which reflects the beam. Other fixtures position the light beam by mounting the light source and optical components in a movable yoke. Still other fixtures are hybrids of the moving mirror and moving yoke fixtures.
Many of these lighting fixtures contain optical components for collecting the light from the light source into a light beam and modifying that light beam. Frequently, these components also have moving elements that can be remotely controlled. Different types of motors are used in various fixtures to drive the moving components of these fixtures. Many of these fixtures employ the use of motor driver circuitry which is typically controlled by microprocessor circuitry.
When a power supply is applied to the above-described fixtures, the motors maintain the position of each part. However, when the power supply is removed, many of these motors no longer hold the position of each part and the part position adjusts based on external forces such as gravity.
The above-described lighting fixtures are often used in traveling performances. Typically, when moving to a new venue, each lighting fixture is removed from the stage and often packaged in a road case which includes foam protection to keep the fixture in a set position during travel. However, frequently, fixtures travel without a case. In both scenarios, the moving parts of the fixture make moving and packing the fixture difficult.
In one method of maintaining fixture position when power is not applied, a key can be used to mechanically lock the fixture into a desired position. In this position, the fixture can be properly loaded into a road case or moved from one position on a stage to another. However, this method of maintaining fixture position requires that a lighting technician physically lock each fixture into position and keep track of a key to do so. It also results in significant inconvenience if some of the fixtures have not been unlocked and are installed in places that are not within easy reach.
The present invention is defined in the independent claims to which reference should now be made. Preferred features are laid out in the subclaims.

Brief Description of the Drawings

Fig. 1: illustrates a side view of a fixture head, yoke and base.
Fig. 2: illustrates a solenoid in a unenergized position.
Fig. 3: illustrates a solenoid in an energized position.
Fig. 4: illustrates a side view of a fixture head, yoke and base in the home position.
Fig. 5: illustrates a front view of a fixture head, yoke and base in the home position.
Fig. 6: illustrates a front view of a fixture head where the extended solenoid capsule locks the head in a shipping position.
Fig. 7: illustrates a front view of a fixture head where the retracted solenoid removes a lock from the head.
Fig. 8: illustrates a front view of a fixture head where the retracted solenoid allows a stop to engage into a locking aperture.
Fig. 9: illustrates a front view of a fixture head where the extended solenoid removes a stop from a locking aperture.
Fig. 10: illustrates a hardware architecture for a microprocessor controlled solenoid locking system.
Fig. 11: illustrates a flowchart of the shutdown routine.
Fig. 12: illustrates an alternative locking drive mechanism.
Fig 13: illustrates another alternative locking drive mechanism.

Detailed Description of the Invention

Fig. 1 illustrates a typical moving yoke automated light fixture 8. These fixtures typically include: a head 10 which includes the light source (not shown) and various optical components (not shown) for modifying the light generated by the light source, a yoke 20 and a base 30. The fixture head 10 is held between a pair of yoke arms 22 and 24, centered about a tilt axis 26. The yoke cross-member 28 is attached to the base 30, centered about a pan axis 32. Typically, these fixtures employ electric motors (not shown) to rotate the fixture head 10 about the tilt axis 26 and rotate the yoke 20 about the pan axis 32. Typically, these motors are driven by motor driver circuitry (not shown) and software located in either the base 30 or in the yoke 20. The yoke 20 or the base 30 also typically includes communication and control circuitry (not shown) for controlling the motor drivers (not shown) and for communicating with a remotely located controller (not shown) though a communications link 38.
Typically, when power (not shown) is removed from a fixture, such as automated fixture 8, the motors no longer hold the position of the fixture head 10, the position of the yoke 20, and other moving parts. Thus, without power supplied to the fixture, the moving parts are free to rotate in response to external forces. When moving automated luminaires from venue to venue, it is not desirable for the fixture head 10 and yoke 20 to be allowed to rotate freely. In accordance with the present invention, one method to solve this problem utilizes electronic solenoid locking mechanisms
Fig 2 illustrates the major components of a solenoid 60. Solenoids convert electrical energy into force and motion. The solenoid in Fig. 2 is in a non-energized state where no power is supplied to the power inputs 70. The solenoid capsule 68 is maintained in a state extended from the solenoid chamber 66 by a spring 80. When electric power is applied to power inputs 70, electric current flows though the coils 65 energizing the coils. Fig 3 illustrates the solenoid 60 with power supplied. The energized coils create an electromagnetic force 62 around the coil. The magnetic force 62 retracts the capsule 68 into the solenoid chamber 66, compressing the spring 80. When electromagnetic force is removed, the capsule 68 extends out of the solenoid chamber 66 by the force of the spring. The spring resists movement of the capsule 68 into the solenoid chamber 66 without a greater opposing force. In the embodiment of the invention shown the design makes use of a compression spring or a leaf spring. In other embodiments of the invention the design can make use of a tension spring. Similarly, the embodiment shown uses a spring internal to the solenoid. In other embodiments of the invention the spring can be configured to be external to the solenoid. Additionally, other components such as lever arms could be incorporated into the design. The objective is to provide tension between an energized open position and an un-energized locked position.
In implementing various embodiments of the present invention, different solenoid characteristics such as the force applied and the diameter of the capsule might be chosen to suit the design of the fixture's components. In addition other solenoid configurations and characteristics may be used without departing from the spirit of the present invention.
Figs. 4 and 5 illustrate a suitable implementation of the of a moving yoke fixture 8 in its shipping position in which the fixture is parked. This position is a typical desired position of a fixture in a road case because the fixture is in its most compact form to minimize the volume of the road case. In the figures, the width of the yoke 20 is aligned parallel to the width of the base 36 and the length of the head 10 is aligned perpendicular to the base 30. For the fixture shown, the shipping position is ideal because the width and length of the road case are determined by the base which also provides balance and support for the yoke 20 and head 10 suitable for travel without a road case. Other positions are also possible and in some cases might be preferable.
In Fig. 6, the solenoid capsule 68 is shown in the arm 22 of the fixture 8 in its extended state where the solenoid coils (not shown) are not energized. The solenoid capsule 68 is shown extended into an aperture 72 in the head 10 of the fixture. In this state the head of the fixture is prevented from tilting. Alternately, in Fig. 7 the solenoid capsule 68 is shown in its retracted state where the solenoid coils (not shown) are energized. The solenoid capsule 68 is shown retracted from the aperture 72 in the head 10 of the fixture.
When power (not shown) is applied to the fixture 8, the solenoid 60 is energized causing it to disengage. With the solenoid disengaged the fixture head can now be freely moved by the motor (not shown) tasked with this function. When power to the solenoid 60 is cut off, the solenoid capsule 68 is extended and then the head 10 can be tilted until the capsule 68 engages the aperture 72 in the head 10 holding the head 10 fixed in its shipping position
Figs. 6 and 7 only illustrated a locking mechanism for the tilting of the head of a moving yoke fixture. The invention can also be applied to the panning of the yoke, and also to the movement of other components such as focusing lens assemblies or other moving components of the fixture. It should also be appreciated that although the embodiment illustrated shows the solenoid mounted to the fixed component (the yoke arm in this case) and the aperture is placed on the moving part (the head in this case), the invention could be implemented in reverse mounting the solenoid on the moving part and placing the aperture on a fixed part.
Additionally it is possible to implement the present invention to utilize solenoids that extend when energized. Such an implementation is illustrated in Figs. 8 and 9 where the extended solenoid removes a stop from a locking aperture. Fig. 8 illustrates a solenoid 60 with a solenoid capsule 68 in its retracted state where the solenoid coils (not shown) are not energized. The stop 78 is extended into the apertures 74 and 76 to hold the head 10 in its shipping position. Fig. 9 illustrates the solenoid in its extended state where the solenoid coils are energized. The stop 78 is retracted from the apertures 74 and 76 by the force of the solenoid capsule 68 against the stop 78. In this embodiment of the invention the tension to provide a locked position could be provided by a tension spring 80 between the stop 78 and yoke arm 22; it could also be provided by the tension spring 80 in the solenoid chamber 66 (not shown).
In some embodiments of the present invention the locking mechanism is directly connected to a suitable power supply for driving the solenoid whenever power is supplied to the fixture. In this case when the power is disengaged from the fixture, the position of the locking part needs to be moved by some external force to the locking position so that the extended solenoid capsule can engage the locking position aperture 72. For panning and tilting movements, manual movement by a stage hand or operator would be suitable.
In other embodiments of the present invention, see Fig. 10, the solenoid 60 is connected to a suitable power supply 100 through an electronic switch 102 which can be controlled by the light fixture's microprocessor circuitry 104. In this way the microprocessor (not shown) can control the energizing the solenoid 60 to unlock the fixture.
With this arrangement, it is possible for the operator to control engaging of the locking solenoids from the remote control desk 106 or through the use of the input key(s) 34 and display(s) 36 on the fixture 8 shown in Fig 1. Such operator control could be facilitated through software in the control desk and/or the fixture.
The implementation of this switch arrangement can also be used to control the engaging of the locking solenoids in an automated fashion. For example as part of an automated shutdown routine, solenoid can be deenergized first and then the moving part drives can be engaged to move the part until the solenoid capsule locks the part in position. Fig. 11 is an illustration of the flowchart of a software routine for an automated shutdown locking system. In block 90, the fixture receives instructions to power down from a signal through the communications link 38. In powering down, the lamp is shut off and other components of the fixture are readied for shutdown. Next, in block 91, the power to the solenoids is shut off such that the solenoid capsule is allowed to extend from the solenoid. It might be desirable to drive the moving part to a position close to its locking position before engaging the solenoid. Following, in block 92, the drive mechanism is engaged for moving parts that lock to a home position whereby the solenoid capsule engages into an aperture in the moving part. It may also be desirable to drive the moving part back and forth repeatedly over a range of motion near the locking position to ensure the locking mechanism engages the locking aperture. Finally, in block 93, the fixture is shutdown to stop receiving power or a display is shown that the fixture is parked and ready to be disconnected from power. The selection and design of power supplies, control circuitry and for any software source code for implementing the control these embodiments of the invention is well within the skill of an engineer in the automated lighting fixture arts.
In other embodiments of the invention the solenoid may be of the type that is not spring loaded but rather has at least two fixed positions: retracted and extended. Rather than a spring to provide tension to drive the capsule to a particular position, these solenoids apply tension to the capsule to restrict it from moving from its existing position. These solenoids may operate by applying one polarity signal to the coil to put the capsule in a retracted position and the opposite polarity to put the capsule in an extended position. Other solenoids of this type utilize two different coils: one coil is energized to retract the capsule, the other coil is energized to extend the capsule. With both of these solenoids, the capsule will remain in the set position after the current is removed from the solenoid.
The advantage of these later two solenoids is that the solenoids do not need to be maintained in an energized state to keep the fixture unlocked or locked.
In other embodiments of the invention, the solenoid can be replaced by a motor such as a stepper motor, a servomotor or a DC motor that drives a mechanism for locking the moving part in place. Figs. 12 and 13 illustrate examples of a motor driven system. In Fig. 12 the motor 110 rotates a spur gear 112 which meshes with a toothed section of a chamber 114. When the gear is rotated the chamber 114 can be moved into and out of a locking position. A spring 118 can be employed for motors that do not return to locked position on power down to return the chamber 114 to a locked position. In Fig. 13, the motor 110 actuates an arm 116 which positions the chamber 120 into a locked and unlocked position. In some embodiment a spring 118 may be employed to ensure that the chamber remains in a locked position when no power is supplied to the fixture. In these systems actuating the motor can cause the locking chamber to lock and or unlock the movement of a moving part 10. Although they are not shown, suitable control circuitry and software of various motor types is well known with skill of an artisan in the automated lighting art.

Claims

An automated lighting fixture comprising:

a movable element whose movement is capable of being remotely controlled; and

a locking mechanism for disabling the movement of the movable element.
The automated lighting fixture of claim 1, wherein the moveable element is a rotatable yoke with a motor to actuate the rotation of the yoke.
The automated lighting fixture of claim 1, wherein the moveable element is a rotatable head with a motor to actuate the rotation of the head.
The automated lighting fixture of claim 3, wherein the rotatable head contains the light source optical components to modify the light emanating from the fixture.
The automated lighting fixture of claim 1, wherein the moveable element is a focusing lens assembly.
The automated lighting fixture of claim 1, wherein the locking mechanism is a solenoid driven locking mechanism.
The automated lighting fixture of claim 6, wherein the solenoid driven locking mechanism is remotely controlled to activate prior to the power being removed from the lighting fixture.
The automated lighting fixture of claim 7, wherein the moveable element is remotely controlled to move to a position where the solenoid driven locking mechanism disables the movement of the moveable element before the power supply is removed from the light fixture.
The automated lighting fixture of claim 7, wherein the moveable element is moved by external force to a position where the solenoid driven locking mechanism disables the ovement of the moveable element.
The automated lighting fixture of claim 6 wherein the solenoid driven locking mechanism extends when the power is removed from the light fixture.
The automated lighting fixture of claim 10 wherein the moveable element is moved by external force to a position where the solenoid driven locking mechanism disables the movement of the moveable element after the power is removed from the light fixture.
The automated lighting fixture of claim 6, wherein the solenoid driven locking mechanism engages into an aperture in the moveable element for disabling the movement of the moveable element.
The automated lighting fixture of claim 6, wherein the solenoid driven locking mechanism disengages from an aperture in the moveable element for enabling movement of the moveable element when power is supplied to the lighting fixture.
The automated lighting fixture of claim 1, wherein the locking mechanism maintains the disabled position of the moveable element when no power is supplied to the lighting fixture.
An automated lighting fixture comprising;

a. a rotatable yoke

b. a motor to actuate the rotation of the yoke.

c. a rotatable head which contains the light source optical components to modify the light emanating from the fixture

d. a motor to actuate the rotation of the head

e. a solenoid driven locking mechanism for disabling the movement of the yoke and head in a parked position when no power is supplied to the fixture and enabling movement of the yoke and head when power is supplied to the fixture.
The automated lighting fixture of claim 15 wherein the yoke is supported by a base.
The automated lighting fixture of claim 15 wherein the solenoid driven locking mechanism is remotely controlled to engage before the power is removed from the lighting fixture.
The automated lighting fixture of claim 17 wherein the yoke and head are remotely controlled to move to a position where the solenoid disables the movement yoke and head before power is removed from the lighting fixture.
The automated lighting fixture of claim 17 wherein the yoke and head are moved by an external force to a position where the solenoid disables the movement of the moveable element.
The automated lighting fixture of claim 15 wherein the solenoid driven locking mechanism engages when power is removed from the lighting fixture.
The automated lighting fixture of claim 20 wherein the yoke and head are moved by external force to a position where the solenoid disables the movement of the yoke and head after the power is removed from the lighting
The automated lighting fixture of claim 15 wherein the solenoid driven locking mechanism engages into an aperture in the yoke and head for disabling the movement of the yoke and head.
The automated lighting fixture of claim 22 wherein the width of the yoke is aligned parallel to the width of the base and the length of the head is aligned perpendicular to the base.
The automated lighting fixture of claim 15 wherein the position of the yoke and head disabled in the parked position utilizes the least volume of space.