Abstract:
A mobile classroom presentation cart ergonomically assembles data, audio, video and interactive presentation equipment; provides security and storage for the equipment and related supplies, transports and provides a fully integrated platform for providing audio-visual presentations. An externally adjustable projector shelf provides for convenient adjustment of a projected image while an enlarged projector door provides an expanded light opening extending into a top of the equipment cabinet. A collapsible side shelf is supported by and retains open a front door of the cabinet. Other features support fabrication and/or modification of carts to provide a desired height including sets of cold shear lines and associated mounting holes associated with a selectable lower edge of the cabinet body. A cart of a desired height can be fabricated by cutting along a cold shear line and attaching the body to a base portion using the associated attachment holes and suitable fasteners.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is directed to a cart and particularly a mobile classroom presentation cart providing a platform for operating, transporting and securely storing audio-visual equipment. 
         [0003]    2. Description of the Related Technology 
         [0004]    Since teaching began the teacher to student relationship has been that of presenter of knowledge, to receiver of knowledge. Education in a classroom setting by a teacher to a group of students has proven to be a successful and effective method of teaching. A student in a classroom can ask a question, and not only that student, but the entire class can benefit from the discussion that brings forth it&#39;s conclusion. The design of the classroom today is based on a seating arrangement that focuses students towards a teacher. This teacher has various display devices, chalkboard, dry erase board, charts etc. These devices are normally placed in the front of the classroom and are mounted at ergonomic heights to allow optimum viewing by the students and optimum control by the teacher. A large number if not the majority of the classrooms in the world are built and configured in such a manner as described. 
         [0005]    Due to limitations in classroom design and available space it is often difficult to integrate effective presentation technology into a classroom space such as was previously described. That is, it is often difficult to optimize and present all of the tools a teacher needs or desires to empower their students with visual information. Many classroom technology solutions compete for available presentation space and/or require the technology to be permanently integrated into and/or installed as part of the classroom. Under these circumstances school systems may be forced by economic constraints to choose some limited number of classrooms that are to include the technology and which classrooms will not. Alternatively, classroom with the technology my not be using it effectively. 
         [0006]    In the past a variety of methods existed to provide suitable visual display information. The overhead projector was widely used in classrooms to display real-time and/or preprinted information and project it to a screen in the front of the classroom. Often a video monitor or television set with a VCR or other video playback device was incorporated into a viewing cart to provide a prerecorded and/or off-air broadcast review capability. The previously mentioned processes all required space to be taken from the presentation area in front of the classroom. 
         [0007]    Konopka, U.S. Pat. No. 6,315,308, entitled Mobile Data/Audio/Video/Interactive Presentation Cart, describes a mobile platform or cart that ergonomically assembles video, audio, data aid power management devices. This platform aligns these devices to insure their safe transport and optimum presentation capabilities. The platform and arrangement of devices conserves use in a classroom setting to enhance the classroom teachers&#39; presentation capabilities. The Mobile Data/Audio/Video/Interactive Presentation Cart also allows school and classroom teachers to safely transport and share the technology from classroom to classroom as required. 
         [0008]    Konopka, et al. U.S. Pat. No. 5,850,250, describes a distance learning classroom system that requires an entire classroom be renovated with technology including a plurality of monitors and cameras, This system while effective in the delivery of distance learning technology is a stand alone classroom and cannot be easily moved to other classrooms in the school. Likewise this classroom little resembles the model of a traditional classroom that has proven effective in its design world wide. 
         [0009]    Fraquelli et al. U.S Pat. No. DES. 417,980 displays a platform that is stabilized with a lower wheeled assembly. It has a shelf for computer equipment and a stalk to support it. 
         [0010]    Nichoalds U.S. Pat. No. 4,718,741, describes an electrified table top. This table top is mounted on a wheeled cabinet and has a wire management system that allows a power cord to be selectively plugged into a conventional power supply receptacle. 
         [0011]    Sweere et al., U.S. Pat. No. 5,918,841 describes a rolling cart for a computer and flat panel display panel includes a base with plural cantered wheels, a mounting pole projecting upward from the base, at least one pole mounted bracket, a pivot support bracket supported by the pole mounting bracket and securing a support arm which is suitable for supporting a flat panel display. 
         [0012]    The computer keyboard and flat panel display cart disclosed in Sweere et al. U.S. Pat. No. 5,918,841 has a number of significant drawbacks. For example the computer platform located on shelf  1220  is the means by which bottom loading or stability for the cart is achieved. This assumes that future computers will be of significant weight to overcome the top heavy equipment placed on the upper mounting brackets. The display cart of Sweere et al. also appears to lack means to effectively control the cabling necessary to connect the components mounted on the brackets. And finally this design fails to safely protect the components it supports, a highly desirable requirement in a classroom. 
         [0013]    Heretofore, prior art computer carts and electrified tables and support structures have been limited to devices that hold, position and manage devices but did not provide an integrated solution to storage, security transport, and operational positioning of audio-visual and related presentation equipment. 
       SUMMARY OF THE INVENTION 
       [0014]    The present invention is directed to a mobile classroom presentation cart that ergonomically assembles data, audio, video and interactive presentation equipment; provides security and storage for the equipment and related supplies, transports and provides a fully integrated platform for providing audio-visual presentations. Embodiments of the present invention incorporate features such as an externally adjustable projector shelf and projector hatch or door providing an expanded light opening into a top of an equipment cabinet for projecting an image at least partially through the top of the cabinet. Embodiment further include a collapsible side shelf which, when lifted into a horizontal position for use, is supported by and retains open a front door of the cabinet. Still other embodiments of an equipment cabinet or cart according to the invention facilitate fabrication by including sets of cold shear lines or grooves and associated mounting holes associated with a selectable lower edge of the cabinet body. A cart of a desired overall height can then be fabricated by cutting along a cold shear line as necessary and then attaching the body to a base portion using the associated attachment holes and suitable fasteners. 
         [0015]    The present invention includes embodiments having the one or more of the following features: 
         [0016]    a) Enclosed ventilated side panels and front and rear side-hinged doors to protect equipment and components from damage and theft; 
         [0017]    b) Hinged side shelf swings up into a working position and is supported in place by and rests atop the rear cabinet door ensuring that door is secured open and out of the way so as to provide equipment ventilation during operation; 
         [0018]    c) Hinged projector door provides opening extending into portion of top shelf area to accommodate full image projection onto screen from video projector positioned within cabinet; 
         [0019]    d) Video Projector tilt shelf has a double tilt axis allowing shelf to (i) rotate about a lateral axis of the projector to adjust picture height as projected onto a screen, and (ii) rotate about a longitudinal axis to adjust and level the projected image; 
         [0020]    e) Power cord floorguard is a vinyl protective molding attached to the bottom rear of the cart using an angle bracket to prevent personnel from tripping over the power cord and provide appropriate positioning distance of the cart from the projection surface; 
         [0021]    f) Alternate power cord opening provided through and out of bottom shelf of cart; 
         [0022]    g) Modular construction providing for adjustable heights; and 
         [0023]    h) Internal wire chase for cable management. 
         [0024]    Embodiments of the present invention may include features to automatically align and support a video/data projector. This projector, when placed on the designed shelf mounting station, is prepositioned to assume the correct angle for viewing and focus. The target for the images created by the video/data projector may be a suitable viewing surface such as a flat or curved reflective screen such as a projector screen typically located above a classroom chalkboard. This screen may be angled to provide increased and/or near-perfect linearity with the images being projected from the video/data projector. According to a preferred embodiment, during an instructional session, a communications feed, a power feed, and video cable feed may be connect to the cart on one end and, on the other end, to a connectorized outlet. Cables may be housed in a flexible vinyl molding to provide this assembly of feeds. The molding may be connected to the cart and, when it is deployed to the outlet, the length of the molding may automatically establishes the correct focus distance for the video/data projector with respect to a viewing screen. It would be expected that all or most classrooms that are configured to use carts according to various embodiments of the invention will have an outlet to provide the communications, power and video feeds. 
         [0025]    Each classroom should also have a viewing screen mounted above the outlet and, for example, above any chalkboard. This viewing screen aligns with the projector to insure images are presented in a linear, undistorted (e.g., minimizing key stoning and similar effects) and clear format. Students and the instructor preferably face the screen to view video and data images. The base of the cart may support and provide adequate storage and mounting room for a computer (e.g., CPU), a printer, and related equipment and/or accessories. These devices may be connected to each other, other equipment installed on the cart, external devices, systems and data/communications networks by cables and wire management systems located in the sides of the cart. 
         [0026]    The CPU monitor is supported at some ergonomically advantage height, e.g., average standing eye level, using a shelf. The shelf may include a tie down system that secures the monitor to the cart and reinforces the monitor&#39;s stability. A foldable, retractable or permanent keyboard shelf may be located on the front of the cart and provides a stable platform to input data from a person standing in front of it. In a preferred configuration, equipment and other devices are mounted and/or position by, on and in the cart so that a classroom teacher may stand at the cart and present images front the monitor and simultaneously project the images onto a screen. 
         [0027]    A CODEC (coder decoder) may be included to provide video teleconferencing capabilities. The CODEC may be mounted and/or installed on the top monitor shelf or on the CPU shelf below. A camera may be mounted on top of the monitor. According to one embodiment the camera may be fixed, manually positionable or have a pan and tilt robotic control. 
         [0028]    A document camera may have a mounting station on the monitor shelf and may further include a folding document shelf located below its lens field of view. This documents shelf may be configured for the placement of flat materials, such as papers and books, and/or support 3 dimensional objects such as models, specimen, etc.. The document shelf may be configured to fold downward for transport or when not being used. A single student microphone and a single teacher&#39;s microphone may be stored in a storage station located on the base of the cart and deployed external to the cart when in use. According to an alternative configuration, shelves may be fixed to the cart to support one or more loudspeakers in an appropriate position and orientation so as to proved improved sound quality and direct/focus sound at an audience (e.g., students). According to a preferred embodiment, audio may be provided and delivered by a sound system located in the projector with an appropriately located and configured grill and/or other means to allow sound to be directed out from the projector towards the audience. A shelf located in the front of the cart may support video reproduction and playback equipment such as a videocassette recorder (VCR), digital videodisk player (DVD), digital video recorder, etc. This shelf may have suitable wire management resources to support multiple types of such devices, singularly and in combination. The VCR, DVD shelf may be configured to locate the playback device to facilitate quick and unimpeded insertion of videotapes, digital disks, or other changeable media. 
         [0029]    A “push and grab bar” may be located in and/or mounted to the front of the cart. This bar provides for cart maneuvering and positioning and maintains screen to projector alignment by the classroom teacher or other user of the cast. The cart may be supported on a soft-wheeled system that uses (2) two ridged and (2) swivel castered wheels. 
         [0030]    Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following and the accompanying drawings or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]    These and other features, aspects and advantages will become clearer with regard to the following description, claims and accompanying drawings wherein the drawing figures depict preferred embodiments of the present invention by way of example, not by way of limitations. In the figures, like reference numerals refer to the same or similar elements. 
           [0032]      FIG. 1  is an perspective view of a mobile presentation cart with a front equipment door closed; 
           [0033]      FIG. 2  is an perspective view of a mobile presentation cart with a front equipment door in a fully open position, engaging and supporting folding side shelf; 
           [0034]      FIG. 3  is a detailed drawing of a locking device for securing the equipment door closed; 
           [0035]      FIG. 4  is perspective view of a side and rear a mobile presentation cart; 
           [0036]      FIG. 5  is an perspective view of the rear of a mobile presentation cart with rear projector door  401  in a closed position; 
           [0037]      FIG. 6  is an enlarged perspective view of an internal projector tilt shelf; 
           [0038]      FIG. 7  is an exploded perspective view of a vinyl molding cable assembly; 
           [0039]      FIG. 8  is a side view of a mobile presentation cart showing break off indent lines; 
           [0040]      FIG. 9  is a rear view of a mobile presentation cart showing break off indent lines; and 
           [0041]      FIG. 10  is a side view of mobile presentation cart showing break off indent lines. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0042]      FIG. 1  is a perspective view of the cart  100  with its front equipment door  101  closed. Hinge  102  connects the door to cart side panel  103 , and allows the door to swing outward to position  102  as in  FIG. 2 . In a preferred embodiment hasps  203  and  204  protrude through door slots  205  and  206  as can be viewed in  FIG. 1 ,  104 , and  105 . This configuration allows a padlock  300  ( FIG. 3 ) to be applied inside the hasp hole  203  preventing door  202  from swinging from it closed/locked position as depicted in  FIG. 1  position  101 . This arrangement provides for the protective security of the components to be placed inside cart  100 . 
         [0043]    Folding side shelf  107  in  FIG. 1  is attached to side panel  103  using piano hinge  106 . When side shelf  107  is in its upright position door  202  may be opened and positioned underneath shelf  107 . Shelf  107  is raised slightly above door  202  and side shelf  107  is lowered onto and supported by a tope edge of door  202 . Shelf  107  has a slot  207  cut to align and secure door  202  at a fixed 45° angle from side panel  103  when shelf  107  is lowered onto its top surface. This configuration provides optimal support for folding shelf  107  and any objects resting upon the shelf. This configuration maintains the equipment door  202  in an open position during operation of the integrated components and ensure that adequate ventilation is provided for the various equipment and components operating inside of cart  100 . Equipment shelf  208  is a flat surface with openings  209 ,  210  that allow connector wires and cables to flow up and down inside of the cart. Hole pattern  210  provides a connection point for plastic wire cable ties and aligns them into opening  209  of equipment shelf  208 . The mobile cart is includes a plurality of drilled, punched, or otherwise formed holes  108  that allow a plurality of shelves  208  to be positioned and attached to walls or side panels  103  and  212  suing appropriate brackets or other attachment hardware or devices. Shelf  208  is perforated with slots  211  that provide anchor points for equipment hold down straps (not shown). Shelf  208  is also perforated with ventilation holes  213  to assist in and facilitate equipment cooling and cable attachment. 
         [0044]    Push handle  109  is a tubular structure attached to a top portion of cart  100  and is ergonomically designed to provide a grip point to control movement of the cart. Foot push bar  110  is a similar tubular structure albeit attached at lower portion of cart  100 , ergonomically designed to provide a stationary pedal to leverage the cart upward over room to room thresholds. 
         [0045]      FIG. 4  is a side and rear perspective of cart  100 . Rear projector door  401  is attached to a rear panel of cart  100  by hinge  402  to swing up and downward to cover projector opening  405 . Projector opening  405  provides unique clearance above and in front of an LCD projector within cart  100  on projector tilt shelf  406 . This design allows the cone shaped light that projects from an LCD projector to clear the top of the enclosing structure  409 . This top clearance allows the LCD projector to be tilted at an aggressive angle on LCD tilt shelf  406 . The light projection geometry inherent in all LCD projectors allows shelf  406  working in concert with opening  405  to optimize LCD projector projection angles insuring the light projection geometry does not strike the inside edges of opening  405 . 
         [0046]    Projector tilt shelf  406  pivots upward and downward on pivot point  410  and locking knob  407 . Locking knob  407  is threaded into the tilt shelf  406 . Clockwise rotation tightens knob  407  against cart wall  400 . When locking knob  407  is tightened so as to secure the knob against wall  400 , projector tilt shelf  406  is thereby locked into and secured in position. Projector tilt shelf  406  also yaws from side to side, i.e., rotates about a lateral axis for adjusting a tilt of the shelf whereby a leveling of the projected image may be achieved. Pivot point  410  is loosely fitted to shelf  406 . Slot  408  located on wall  400  allows projector tilt shelf  406  to yaw from side to side when locking knob  407  is loosened and moved up and down within yaw slide slot  408 , i.e., adjusted about a transverse axis connecting locking knob  407  and pivot point  410  for adjusting a pitch of the shelf whereby a vertical positioning of a projected image may be achieved.  FIG. 4  shows the projector tilt shelf  406  tilted slightly upward about its transverse axis and the side to side yaw is level and centered in yaw slide slot  408 , i.e., about its lateral axis. 
         [0047]      FIG. 5  is a perspective view of the rear of the cart with rear projector door  401  in the upward and closed position. Hasp  403  is protruding through slot  404  to provide means for locking door  401  in an closed position. Projector door  401  completely closes the opening  405  and secures access to the inside of cart  100  through opening  405 . In a preferred embodiment, padlocks are placed in hasp holes  403 , preventing slot  404  in door  401  from sliding over hasp  403 . In an alternate embodiment flush mounted key locks may be placed on door  401  and lock bars rotated into a locked position behind the side walls  103  and  400  to prevent door  401  from opening.  FIG. 5  also demonstrates the vinyl cable molding assembly  703  in a deployed configuration for providing a conduit from the equipment mounted in cart  100  to external connection points. This assembly attaches to the cart with friction clamp  701  that also secures vinyl molding assembly  703  with its communications cable(s)  704  to the cart structure. When cut to the proper length the vinyl cable molding assembly establishes critical cart-to-viewing-screen distances and provides a flat non-trip cable path. 
         [0048]      FIG. 6  is an enlarged perspective view of projector tilt shelf  406 . Strap slots  602 ,  605 ,  606 ,  607 ,  608 ,  609  are designed to provide strap hold down points for an LCD projector (or other equipment) placed on top of shelf  406 . This strap and slot configuration allows positive attachment of the projector to the shelf during tilt and yaw adjustments so as to positively secure the projector to the shelf and avoid slippage and movement. In addition to strap slots  602 ,  605 ,  606 ,  607 ,  608 ,  609  a longer slot  604  is provided to attach a through-bolt to the proposed LCD projector. Hole patterns  610  and  611  are designed to allow flow through ventilation from below the shelf  406  provided by natural or forced-air convention. 
         [0049]      FIG. 7  is an exploded perspective view of the vinyl molding cable assembly  703  and clamp  701 . This assembly is anchored to the cart using anchor base  702  that is attached to the cart. Bolts  707 ,  708  are permanently fixed to anchor base  702 . The bolts are of sufficient length to allow the vinyl molding cable assembly  703  to be placed between bolts  707 , 708  and allow clamp  701  to be tightened down in place over the assembly using wing nuts  705 , 706 . This assembly allows the vinyl molding  703  to protrude through opening  409  as seen in  FIG. 4 . 
         [0050]      FIG. 8  is a side view  400 , of cart  100  depicting break off indent lines  801 , 802 , also referred to as score lines. Score lines  801 , 802  may be produced by etching during the material press process that provide measured, incremental, cut points. Cut points provided by score lines  801 , 802  provide measured, incremental, cart height adjustment or fabrication points when material is removed below lines  801 ,  802 . This process also replicates attachment holes  803  to align with the altered side  400 , allowing it to be attached securely and successfully. The break off process is performed in the last stages of manufacturing. It provides to the production of a single height of side  400  that can be later readily modified and incrementally adapted during assembly to a specific desired height as customer requirements are identified. 
         [0051]      FIG. 9  is a rear view of the cart showing break off indent or score lines  901 , 902 . Score lines  901 , 902  are etched lines produced in the material press process that provide measured, incremental, cut points. Cut points implemented by score lines  901 , 902  provide measured, incremental, cart height adjustment when material is removed below lines  901 , 902 . This process also replicates attachment holes  903  to align with the altered rear of the cart, allowing it to be securely and successfully attached. Cut outs  904 , 905  provide accurate cut points to align with cut points  901 , 902 . The break off process is performed in the last stages of manufacturing and/or as part of an assembly process so as to provide for mass production of a standard, maximum height rear panel that may be readily incrementally shortened as customer requirements are identified. 
         [0052]      FIG. 10  is a side view  103 , of the cart showing break off indent or score lines  1001 ,  1002 . Score lines  1001 , 1002  are etched lines produced in the material press process that provide measured, incremental, cut points. Cut points  1001 ,  1002  provide measured, incremental, cart height adjustment when material is removed below lines  1001 ,  1002 . This process also replicates attachment holes  1003  to align with the altered side  103 , allowing it to be attached successfully. The break off process is performed in the last stages of manufacturing. It allows only (1) one side  103  to be mass produced and then altered incrementally as customer requirements are identified. 
         [0053]    While the foregoing has described what are considered to be the best mode and/or other preferred embodiments of the invention, it is understood that various modifications may be made therein and that the invention may be implemented in various forms and embodiments, and that it may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all modifications and variations that fall within the true scope of the inventive concepts. 
         [0054]    It should also be noted and understood that all publications, patents and patent applications mentioned in this specification are indicative of the level of skill in the art to which the invention pertains. All publications, patents and patent applications are herein incorporated by reference to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety.