Abstract:
A hinged electrodynamic transducer apparatus is disclosed for providing oscillating and/or vibrational motion. The hinged transducer of the present invention is configured to be robust and low profile for installation under chairs, seats, and other items of furniture such that it can impart vibrational motion capable of being sensed by the human body (DC to approximately 500 Hz.

Description:
RELATED APPLICATION INFORMATION 
     This application claims the benefit of and is a utility application of U.S. provision patent application Ser. No. 61/794,318, which is entitled HINGED MOTION TRANSDUCER. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to an apparatus for converting electrical signals into physical motion through the use of an electromagnetic transducer. In particular, the present invention provides a robust, low profile motion system having one or more hinged elements which may be easily placed under an object or series of objects in order to impart vibrational motion in response to electrical or motion based signals from a wired or wireless signal source. 
     2. Description of Related Art 
     The field of electrodynamic transducers for imparting shaking, push/pull, or other vibrational type motion is well established. In particular, the field of inducing motion in seating systems such that a person seated in the chair experiences vibrational sensations indicative of low frequency (ie. bass) sound includes various types of systems and configurations to accommodate different frequency oscillations. For extremely low frequencies (eg. DC to 20 Hz oscillations) various hydraulic systems, rotary motors with encoders, worm drive systems and sensors for control and position verification (closed-loop) have been used in prior art systems. The applicant for the present invention considered these prior motion systems and found many deficiencies for the applications described in the present invention. Generally, existing seating transducer systems are expensive, complicated to both install and use, and prone to mechanical and other system failures. Generally the complexity and size of these prior art systems require that the mechanical and motion apparatus be integrated in/with the seat in such a way that the seat and motion transducer system must be designed together and produced as one integrated product, and multiple seats in a theater type installation may not share arms or be connected to the adjacent seats, thereby reducing the number of seats that can fit in a room. The backlash in worm drive and hysteresis in the electrical and drive systems also typically limits the operation to around 100 Hz, and since the human body can sense vibration up to approximately 500 Hz, in these systems the range from 100 Hz to 500 Hz cannot be felt by a user. 
     Current art for creating vibration motion in higher frequencies capable of being sensed by the human body (eg. 20 to 500 Hz) in theater seats typically cannot adequately perform below 20 Hz because they employ inertial shaking systems using a moving mass-spring system to vibrate a portion of the seat. Typically these systems are only capable of vibrating the back or cushion area of a seat, and are not capable of moving the whole seat in unison for a realistic motion sensation. 
     Thus, a system and device is needed such that it 1) can be used in conjunction with currently installed theater seats as a retrofit upgrade, 2) performs well throughout the range of motion capable of being perceived by the human body (DC to approximately 500 Hz), 3) responds to a combination of frequencies as opposed to singular frequency oscillations, 4) moves the entire seat in one (up and down), two (tilt, up and down), or three (rock, tilt, up and down) axes, with a simple open-loop analog signal power source and low system cost and complexity. 
     SUMMARY OF THE INVENTION 
     The current invention encompasses a hinged motion transducer which can impart motion to an object (a chair, seat(s), or other similar apparatus in the primary embodiment) in connection with signals from an audio visual presentation system, motion control signal system, or other electronic apparatus capable of driving an actuator (electrodynamic in one embodiment) incorporated with the motion transducer. The current invention is capable of imparting motion through the range or frequencies capable of being sensed by the human body (approximately DC through 500 Hz) as well as accommodating a combination of frequencies simultaneously (such as those frequencies associated with audiovisual presentations). 
     The motion transducer may be used alone to cause vibrations in an object placed on it, or incorporated with other objects such as chairs, in order to impart motion sensations to a person sitting in the chair corresponding to an audiovisual presentation. In one embodiment multiple motion transducers may be used in connection with multiple chairs in order to impart motion to many people at once, such as in a movie theater or similar entertainment venue, the motion corresponding to audiovisual or motion based signals. As will be appreciated from the detailed description below, the present invention can be used with a wide range of existing seats and chairs, and can function with seats that have as little as one supporting foot and a wide range of foot bolt patterns. The present invention can easily be used for retrofit theater installations by bolting down to threaded holes in the floor previously used for directly attaching the seats, and can also withstand large external forces on the seat in all directions allowing minimal seat deflection and movement both after installation and during motion operation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the nature and advantages of the present invention, as well as the preferred mode of use, reference should be made to the following detailed description read in conjunction with the accompanying drawings. In the following drawings, like reference numerals designate like or similar parts throughout the drawings. 
         FIG. 1  is a view showing a theater seating system using multiple hinged motion transducer elements according to the present invention. 
         FIG. 2  is a front view of a single theater seat coupled with two hinged motion transducers. 
         FIG. 3  is a side cutaway view of the preferred embodiment of the present invention. 
         FIG. 4  is an exploded view of the preferred embodiment of the hinged motion transducer of the present invention. 
         FIG. 5  is a top view of the preferred embodiment of the present invention shown in  FIG. 4 . 
         FIG. 6  is a rear cutaway of the preferred embodiment of the present invention shown in  FIG. 4 . 
         FIG. 7  is an isometric view of one embodiment of a long coupled magnet assembly. 
         FIG. 8  is a side view of an embodiment of the present invention. 
         FIG. 9  is a view showing a dual axis embodiment of the present invention. 
         FIG. 10  is a view of one embodiment of a theater seat attachment system in a dual axis embodiment of the present invention. 
         FIG. 11  is an exploded view of the embodiment shown in  FIG. 10 . 
         FIG. 12  is another embodiment of the theater seat attachment system in a three axis embodiment of the present invention. 
         FIG. 13  is an exploded view of the embodiment showing in  FIG. 12 . 
         FIG. 14  is a view showing one embodiment of the current invention including a top moving plate extension. 
         FIG. 15  is an exploded view of one embodiment of the electromagnetic assembly of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present description is of the best presently contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. 
     All publications referenced herein are fully incorporated by reference as if fully set forth herein. 
     The present invention can find utility in a variety of implementations without departing from the scope and spirit of the invention, as will be apparent from an understanding of the principles that underlie the invention. For instance, the present invention is best described as used in conjunction with theater seating and other items of furniture, entertainment systems (including home audio/video equipment, theater or other large public venue equipment, demonstration, laboratory, simulation, or game systems, etc) such that the transducer can vibrate the furnishings in response to electrical signals from the entertainment system, however it may find utility when used with a plethora of systems or devices which are to be moved, oscillated or vibrated, such as laboratory test subjects, dance floors, home theater seating, bed frames, platforms etc. 
     Looking now to  FIGS. 1 and 2 , example transducer apparatus  120  is shown schematically in a theater seating system  100  in  FIG. 1 , and in a front view of a single motion seat  200  in  FIG. 2 , to illustrate the current invention. Transducer  120  is located beneath one or more seat legs  110  of theater seating system  100  or single motion seat  200  in order to impart vibrational motion to a person or other subject in theater seat(s)  105 . Seating system  100  in  FIG. 1  illustrates multiple transducer units  120  mounted under multiple connected theater seats  105  in order to impart vibrational motion during an audio-visual presentation (eg. movie, concert, theater production, etc). Transducer units  120  are electrically connected to each other via system connection wire  130 , and at least one transducer unit is then electrically connected via wire  140  to amplifier  150  which provides the appropriate power necessary to drive electromagnetic assembly  800  in order to cause vibrational motion in theater seating  105 . A motion signal recording  160  may be sent or used by the amplifier  150  to drive the transducer  120  with appropriate vertical acceleration relative to time. Signals from accelerometer  170 , Motion recording  160  or Processor  190  to amplifier  150  can be analog, AES3 or any standard audio signal type. Signals may pass through audio mixing equipment prior to delivery to amplifier  150 . In one embodiment of the present invention accelerometer  170  may be employed to provide additional or supplemental signal input to amplifier  150  in order to drive transducer  120 . Accelerometer  170  may be any device or apparatus that measures acceleration or vibration from the surface of an object. In one embodiment accelerometer  170  may be attached to instruments during a live musical presentation (eg. guitar, bass, drums, stage floors, etc) in order to detect nuanced vibrational characteristics during a performance which may then be imparted to audience members in theaters seats  105  in accordance with the current invention. In another embodiment, the accelerometer  170  may be used to dampen motion in theater seating  105  or other object in contact with transducer  120  by utilizing “noise canceling” or similar processing algorithms in amplifier  150  in order to counteract vibrational motion detected by accelerometer  170 . It may be advantageous to employ such noise cancelling/motion dampening technology in applications such as removing unwanted ground vibration from adjacent theater rooms, or removing yacht, plane, bus, or other vehicular vibrations from seats, beds, or other items of furniture in accordance with the current invention. In the preferred embodiment amplifier  150  is configured as a 100 Wrms/motion transducer, DC to 500 Hz, combination of frequencies, flat frequency response amplifier, the motion recording  160  is linear Pulse Code Modulation (PCM), the cinema audio/video processor  190  is a Qube brand Digital Cinema Processor (such as those available from http://www.qubecinema.com/), and the motion track  175  is linear PCM, however it will be understood and appreciated by those skilled in the art that a variety of different existing devices and systems can be used in connection with the present invention, including integrated systems that include one or more of the above elements in a single device, without departing from the spirit and scope of the present invention. For example, to maintain phase-accurate synchronization with the motion picture sound track, the motion track  180  signal can be carried within the main sound track file from cinema audio/video processor  190  alongside other main sound audio channels 
       FIG. 3  shows a side cutaway view along axis A-A from  FIG. 2 , and  FIG. 4  shows an exploded view, each of transducer  120  to illustrate the current invention. Generally, transducer  120  comprises rigid top plate  370  operatively coupled with bottom plate  380  via a hinge mechanism. In the present embodiment the hinge mechanism comprises hinge shaft  385  in bottom plate  380  inserted in hinge bushing  400  located in top plate  370 . It will be appreciated that a variety of hinge mechanism elements could be used to allow for angular opening/closing motion in top plate  370  with respect to bottom plate  380  without departing from the spirit and scope of the present invention. In order to facilitate vibrational motion in transducer  120  an electromagnetic assembly  800  (shown in an exploded view in  FIG. 15 ) is configured within top plate  370  and bottom plate  380 . Generally electromagnetic assembly  800  comprises return pole  300 , permanent magnet  310 , main pole  320 , coil bobbin  330 , voice coil  340 , and return ring  350 . In the preferred embodiment, a coupled magnet assembly  1500  comprised of return pole  300 , permanent magnet  310 , main pole  320 , and return ring  350  are fixably attached to top plate  370  via screws  410 , while coil bobbin  330  and voice coil  340  are correspondingly integrated into bottom plate  380 . Coil wire  420  connects the voice coil  340 , and wire  140  to complete an electrical circuit with amplifier  150 . Similar electromagnetic assemblies and other configurations of electromagnetic assembly  800  are described in greater detail in U.S. Pat. No. 8,061,210, which is incorporated by reference herein in its entirety. in the preferred embodiment of the present invention, bottom plate  380  of transducer  120  is fixably coupled to floor  390  via screws  374 . Seat leg  110  is fixably attached to mounting nuts  371  in top plate  370  via screws  372 . In the preferred embodiment mounting nuts  371  are press fit PEM nuts with an interior nylon locking feature, however it will be understood and appreciated that many different fastening systems may be used depending on the desired application without departing from the spirit and scope of the present invention. In order to provide resilient support to transducer  120  and support the load from theater seat  105 , compression and tension spring  360  is configured between top plate  370  and bottom plate  380  and fixably held in place by screw  373 . Multiple compression and tension springs may be employed. Compression and tension spring  360  may be made out of rubber, elastomeric material, metal coil, metal flexure, or other springlike material depending on the particular application. 
       FIGS. 5 and 6  are top view and side cutaway view along the B-B axis of transducer  120  respectively, to illustrate the current invention. One or more holes  500  are provided for access by wire  140  to electrically connect with electromagnetic assembly  800 . Additional wires for power or signal provision to transducer  120  may be implemented through holes  500  in order to connect with additional electronic componentry as will be described in greater detail below. A retaining clip  510  is illustrated in connection with hinge shaft  385  in order to hold hinge shaft  385  in place when it is inserted through hinge bushings  400 . 
     Turning now to  FIG. 7 , an alternative long magnet assembly embodiment is illustrated. Coupled magnet assembly  700  is comprised of top pole  710 , center return pole  720 , and magnetic material  740 . Magnetic gap area  730  is configured to receive voice coil  340  with substantially equidistant inner diameter (ID) and outer diameter (OD) gap distances. The coupled stator assembly  700  is ideally sized and arranged to increase the total volume of magnetic material  740  that will fit within the space between top plate  370  and bottom plate  380  and increase the magnetic field strength within gap  730 . Coupled stator assembly  700  utilizes top plate  370  as a magnetic return pole. In this embodiment top plate  370  and center return pole  720  must be constructed from magnetic material. With this design it is possible to use inexpensive ceramic magnetic material as opposed to permanent magnets which are typically more expensive. 
     Turning now to  FIG. 8 , a side profile view of an alternative embodiment of the present transducer invention is illustrated. Transducer  805  includes bottom plate  382  operatively connected to top plate  372  via piano hinge  820 . Top plate  372  in this embodiment is configured with a first plate portion  374  sized and shaped to accommodate electromagnetic assembly  800 , spring element  360 , and other transducer components, and a second plate portion  376  with a lower nominal height with respect to bottom plate  382  in order to support object  830  closer to the floor or other fixed surface on which transducer  805  is placed. Using this configuration object  830 , such as a chair leg, or other portion of furniture can be as close to the floor as possible while still providing for the vibrational motion aspects in accordance with the current invention. The current embodiment also shows electrical amplifier  810  and wireless receiver  840  fully integrated within transducer  805  in order to allow for a compact, portable, and self contained motion vibration system. Electrical amplifier  810  according to the present embodiment is a Class-D, 100 Wrms, DC-500 Hz, combination of frequencies, flat frequency response amplifier, and wireless receiver  840  is a 2.4 gHz radio frequency (RF), DLNA device that can be activated and controlled by a (point of sale) POS system or smart device (ie. smartphone or tablet computer), both of which may be connected to an electrical source via a wire (not shown) or may be battery powered within transducer  805 . The present embodiment shown in  FIG. 8  may be implemented for applications such as an automatic baby crib vibrational system. In this embodiment one leg or portion of a baby crib may be supported as object  830 , and transducer  805  may be used to impart vibrational motion to the crib in response to audio signals (ie. music) sent to wireless receiver  840  by a smart device (ie. smartphone or tablet computer), amplified by amplifier  810 , and driven through electromagnetic assembly  800 . Due to the extremely low profile design of transducer  805 , it is possible that only one leg of a crib may be configured with transducer  805 , without the need for other legs of the crib to be raised to level. It will be understood and appreciated by those skilled in the art that a variety of compact amplifier and wireless receiver elements may be implemented with the current invention depending on the particular size and application of the transducer device, without departing from the spirit and scope of the current invention. 
     Turning now to  FIGS. 9 through 11 , an embodiment for configuration of dual axis theater seat assembly  900  is shown.  FIG. 10  illustrates one side of the dual axis theater assembly  900  shown in  FIG. 9 , and  FIG. 11  is an exploded view of  FIG. 10 . According to the present embodiment two transducer  122  assemblies are arranged such that the axes of hinges  385  are in line with front axis of theater seat  100  (generally the direction of sight that a person sitting in seat  100  would experience), and bolted to the floor using screws  374 . Transducers  122  are functionally and systematically analogous to transducers  120  of the present invention, however transducers  122  are sized and configured to accommodate the dual axis theater seat assembly  900  as illustrated. Legs  110  of seat  100  are mounted to the edge opposite hinges  385  of each transducer  122  via an assembly  1100  comprising half round rod  920  in flush mounted with top plate  370  of transducer  122 , and half round rod bushing  910  mounted to the bottom surface of seat leg  110 . Screws  372  are mounted through spring washers  1000  and then coupled with nuts  371  in top plate  370 . In this embodiment the half round rod  920  and half round rod bushing  910  are operative together during motion induced in transducer  122  to rotate freely as the top plate  370  moves and the angle of top plate  370  with respect to bottom plate  380  changes. The spring washer  1000  provides for secure mounting of the seat  100  to transducer  122  while allowing a slight angle change of seat  100  relative to top plate  370 . The dual axis theater assembly  900  allows each foot of a dual foot seat  100  to be individually actuated to produce a side-to-side or tilt motion as well as an up and down motion. The degree of motion is limited by the clearances around the seat mounting bolts, the max displacement of the spring washer and the range of motion of the electromagnetic linear motor. In this embodiment the seat foot can be replaced with a platform to produce a surface for dual-axial motion and vibration. The rod and bushing elements in this current embodiment can be made of metal and plastic respectively, however it will be understood and appreciated that many different types and configurations of rod and bushing materials may be used for desired configurations in accordance with the current invention. 
       FIGS. 12 and 13  depict an alternate bushing configuration for mounting seat leg  110  to transducer  122 . In this embodiment half sphere  1200  is mounted on top plate  370  opposite the side of hinge  385 . Bushing  1210  having concave half sphere bushing seat  1220  is mounted to seat leg  110  such that rotational contact can be made with half sphere  1200 . Screws  372  are mounted through spring washers  1000  and then coupled with nuts  371  in top plate  370 . In this embodiment the half sphere  1200  and bushing  1210  are operative together during motion induced in transducer  122  to rotate freely as the top plate  370  moves and the angle of top plate  370  with respect to bottom plate  380  changes. The spring washer  1000  provides for securing mounting the seat  100  to transducer  122  while allowing a slight angle change of seat  100  relative to top plate  370 . This configuration allows each foot of a seat with three or more feet to be individually actuated to produce three or more axis of motion. Rocking, tilting, as well as an up and down motion is possible with three hinged motion transducers. The degree of motion is limited by the clearances around the seat mounting bolts, the max angular displacement of the spring washer, and the range of motion of the electromagnetic linear actuator. In this embodiment the seat leg can be replaced with a platform to stand on, or for placement of machines, chairs, or other items of furniture to produce a surface for multi-axial motion and vibration. 
       FIG. 14  illustrates an alternate embodiment of the current invention implementing a plate structure to enhance motion sensation for a user. In this embodiment top moving plate  1400  is rigidly affixed to one or more transducers  120  under seat  105  as illustrated. Top moving plate may be any rigid surface substrate such as metal, wood, plastic etc. which is able to impart the induced motion in transducer  120  to the feet of a user in seat  105 . It will be appreciated that the use of top moving plate  1400  produces a more realistic sensation in a user in seat  105  by allowing that users entire body, including feet, to experience motion sensations from transducer  120 . In other words, a whole body experience can be accomplished via this embodiment as opposed to other embodiments where the users feet may be resting on the ground in front of seat  105  where motion sensations from transducer  120  will not be felt. For convenience in a multi seat setup, top moving plate  1400  may be configured with hinges (not shown) to fold or lift up when seat  105  folds up, or slidable elements such that top moving plate can slide to the back of seat  105  in order to allow access through isles or walkways surrounding seats  105 . Top moving plate  1400  may also be shaped and configured (ie. with angles or bent portions) to be very low and close to floor  390  in order to avoid tripping hazards in a multi seat arrangement while still providing whole body motion sensation according to the current embodiment. 
     It will be appreciated that in addition to the various shapes, sizes, and configurations (collectively the transducer assembly), and bushing and spring assembly arrangements discussed in various embodiments above, many different ways of mounting or integrating the electromagnetic and spring assemblies with the armature top plate and stator bottom plate are possible in order to fashion a robust, low profile transducer assembly in keeping with the spirit and scope of the present invention. Additionally, while the overall transducer housing (as shown and described) comprises top and bottom plates having a substantially square shape, it will be understood that many different transducer housing shapes, sizes, and configurations are possible in keeping with the spirit and scope of the current invention. For instance, circular, triangular, rectangular, hexagonal, octagonal, as well as many other transducer housing (i.e. the top and bottom plates which form the armature and stator portions respectively) shapes and structures may be implemented in conjunction with the current invention. 
     Many additional forms and implementations of the low profile transducer apparatus of the present invention could be contemplated for a variety of purposes without departing from the scope and spirit of the current invention. 
     The system and process of the present invention has been described above in terms of functional aspects in schematic diagram format. It is understood that unless otherwise stated to the contrary herein, one or more functions and aspects of the apparatus may be integrated in a single physical device, or one or more functions may be implemented in separate physical devices, without departing from the scope and spirit of the present invention. 
     It is appreciated that detailed discussion of the actual implementation of each apparatus module is not necessary for an enabling understanding of the invention. The actual implementation is well within the routine skill of a mechanical and system engineer, given the disclosure herein of the system attributes, functionality, and inter-relationship of the various functional modules in the system. A person skilled in the art, applying ordinary skill can practice the present invention without undue experimentation. 
     While the invention has been described with respect to the described embodiments in accordance therewith, it will be apparent to those skilled in the art that various modifications and improvements may be made without departing from the scope and spirit of the invention. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrated embodiments.