Abstract:
A theatrical lift including a timer and an indicator light. The light indicates a need for maintenance after a predetermined amount of time passes as measured by the timer. Also, a lift, such as a theatrical lift, including an indicator, a reset switch and an indicator housing. The indicator is located on the indicator housing. The reset switch is located inside of the indicator housing. The indicator housing can be opened or partially opened to allow selective access to the reset switch. In this way, the reset switch can be easily reset by a lift maintenance technician as part of performing routine maintenance on the lift, but will not be easily reset by a lift operator as a casual matter.

Description:
RELATED APPLICATION 
       [0001]    The present application claims priority to U.S. provisional patent application No. 60/992,861, filed on Dec. 6, 2007; all of the foregoing patent-related document(s) are hereby incorporated by reference herein in their respective entirety(ies). 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to theatrical lifts (see DEFINITIONS section) and more particularly to maintenance of theatrical lifts. 
         [0004]    2. Description of the Related Art 
         [0005]    Mechanical lifts, winches and the like are conventional. Older designs were generally human powered and counterweight assisted. More recent designs are generally motorized. It is conventionally recognized that these devices require maintenance, including both routine periodic maintenance, and non-routine maintenance upon observance of a fault condition. As an example, of routine maintenance, certain lift components may be recommended to be checked by professional at predetermined time periods. As examples of non-routine maintenance, some fault conditions requiring non-routine maintenance might be visible damage, a wholly or partially inoperative lift or an unusual noise heard during operation. 
         [0006]    US patent application 2004/0263100 (“Heravi”) discloses a solid state controller for a winch that includes fault detection for several parameters. In the Heravi system, an indicator light indicates when there is some type of fault. Heravi states: “If a major fault occurs, the winch motor  12  will be stopped and the indicator light  58  will begin to transmit a sequence of blinks. These blinks will indicate what type of fault has occurred. The indicator light  58  will blink a certain number of times to give a fault code. After blinking, the fault code, the indicator light will pause and then repeat the process. For example, two blinks can be utilized to represent motor over-temperature, three blinks for over-load interrupt, four blinks for module over-temperature, five blinks for battery voltage too low or too high, six blinks for wiring and/or power module switch fault, and seven blinks for module over current.” These are all fault conditions that call for non-routine maintenance. 
         [0007]    US patent application 2007/0205405 (“Stockmaster”) discloses an electric lift actuator. The Stockmaster actuator includes remote diagnostic capability that enables remote configuration as well as remote troubleshooting of the lift. Stockmaster further states: “[T]he pendant is fitted with a liquid crystal display (LCD) or similar display technology in order to provide the ability to communicate more readily-available information to a user. The information displayed in the LCD may include basic information such as system status (i.e.: system ready for use), advanced or optional information such as load weight, system usage and service information (i.e.: number of cycles completed and system service indicators) as well as enhanced guidance and feedback when in programming mode such as what feature is currently being programmed (i.e.: virtual limits). By using the LCD it is possible to provide more and different information to the installer, the user and even maintenance staff Once again, as an alternative to the LCD display, conventional light-emitting diodes (LEDs) and the like may be employed to communicate actuator status information to an operator.” (reference numerals omitted) It is noted that Stockmaster is not disclosed to relate to theatrical lifts. It is further noted that Stockmaster apparently bases its system service indicators on number of cycles because it describes its “service information” a “i.e.: number of cycles completed and system service indicators.” 
         [0008]    Description Of the Related Art Section Disclaimer: To the extent that specific publications are discussed above in this Description of the Related Art Section, these discussions should not be taken as an admission that the discussed publications (for example, published patents) are prior art for patent law purposes. For example, some or all of the discussed publications may not be sufficiently early in time, may not reflect subject matter developed early enough in time and/or may not be sufficiently enabling so as to amount to prior art for patent law purposes. To the extent that specific publications are discussed above in this Description of the Related Art Section, they are all hereby incorporated by reference into this document in their respective entirety(ies). 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    One aspect of the present invention is directed to a theatrical lift including a timer and an indicator (see DEFINITIONS section) where the indicator indicates a need for maintenance after a predetermined amount of time passes as measured by the timer. Preferably, the lift further includes a reset mechanism that allows the timer and indicator to be reset when maintenance is performed pursuant to an initial indication by the indicator. 
         [0010]    Another aspect of the present invention is directed to a lift, such as a theatrical lift, including an indicator, a reset mechanism and an indicator housing. The indicator is located in proximity to the indicator housing (for example, on the surface of the indicator housing). The reset mechanism is located inside of the indicator housing. The indicator housing can be moved between a non-access position and an access position. When the indicator housing is in the non-access position, the reset mechanism cannot be accessed from outside of the indicator housing. When the indicator housing is in the access position, the reset mechanism can be accessed (for example, by a tool, by a finger) from outside of the indicator housing. In some preferred embodiments, special tools are required to move the indicator housing from the non-access position into the access position so that access to the reset mechanism is limited to individuals who have the special tools (see DEFINITIONS section). 
         [0011]    Another aspect of the present invention is a lift including maintenance detection module and a lift performance limiting module. The maintenance detection module detects that lift maintenance should be performed. For example, this detection may be based on passage of a predetermined amount of time, number of lift cycles, a time integral of force exerted by the lift and/or the like. When the maintenance detection module detects that lift maintenance should be performed, the lift performance limiting module limits performance of the lift in some way. There are many ways that lift performance should be limited. To name some examples: (i) lift start up time could be increased so that it takes longer to start using the lift after it is turned on; (ii) lift shut down time could be increased so that it takes longer for the lift to completely power down after it is shut off; (iii) delay intervals could be added to non-emergency manual operations of the lift so that the lift responds less quickly to non-emergency operator commands; (iv) range of lift motion could be limited; (v) maximum load could be limited; (vi) maximum speed could be limited; and/or (vii) rendering the lift completely inoperable. In some preferred embodiments the lift performance limiting module progressively limits lift performance more and more with continued lift usage after it has been determined that maintenance is required—in this way, the degree of limitation of lift performance will be correlated with the urgency of the need for lift maintenance. For example, a delay injected into non-emergency command responsiveness can be made hardly noticeable at first, but gradually progressing to the point where the operator realizes that she must get that maintenance done. By limiting the lift performance (short of completely disabling the lift), a compromise may be achieved between the desire to continue to use the lift (for example, in an ongoing theatrical performance) and the important need to do maintenance for safety and efficiency reasons. 
         [0012]    Other aspects of the present invention may include the following: (i) a mechanical lift including a timer and an indicator (for example, an indicator light, a computer network communication), where the indicator is adapted and/or programmed make an indication after a predetermined time interval to thereby indicate that the mechanical lift should receive routine maintenance; (ii) a mechanical lift including a lift usage measuring device and an indicator, where the indicator is adapted and/or programmed to make an indication based on an amount of lift usage measured by the lift usage measuring device to thereby indicate that the mechanical lift should receive routine maintenance; (iii) a mechanical lift including a timer and a maintenance encouragement device, where the maintenance encouragement device is adapted and/or programmed to modify operability of the lift in order to encourage routine maintenance after a predetermined time interval; and/or (iv) a mechanical lift including a lift usage measuring device and a maintenance encouragement device, where the maintenance encouragement device is adapted and/or programmed to modify operability of the lift in order to encourage routine maintenance based on an amount of lift usage measured by the lift usage measuring device. 
         [0013]    Various embodiments of the present invention may exhibit one or more of the following objects, features and/or advantages: 
         [0014]    (i) encourage routine maintenance to increase safety of lifts; 
         [0015]    (ii) encourage routine maintenance to improve energy efficiency and/or operability of lifts; 
         [0016]    (iii) improve lift consumer information by clarifying responsibility for routine maintenance and consequences of failing to perform routine lift maintenance; 
         [0017]    (iv) increase lift safety and security by limiting the ability to reset indicator(s) to certain individuals (for example, individuals having special tools needed to open the indicator housing); and/or 
         [0018]    (v) encourage lift maintenance, and thereby enhance lift efficiency and safety, by limiting operation of the lift until a lift maintenance technician performs routine maintenance required due to passage of a predetermined amount of time and/or lift usage. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which: 
           [0020]      FIG. 1  is a side view of first embodiment of a theatrical lift system according to the present invention with an indicator housing portion shown in cross section; 
           [0021]      FIG. 2  is another cross sectional view of the indicator housing of the first embodiment lift system; 
           [0022]      FIG. 3  is a perspective view of a second embodiment of a theatrical lift system according to the present invention; and 
           [0023]      FIG. 4  is a block diagram of a third embodiment of a lift system according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    As shown in  FIGS. 1 and 2  theatrical lift system  100  according to the present invention includes: controller housing  102 ; connection hardware  103 ; indicator LED  104 ; controller programmable logic circuitry  106 ; light on/off switch  109 ; timer reset  110 ; lift motor and gear train  114 ; drum  116 ; frame  118 ; head sheave  120  and cable  122 . Circuitry  106  includes: ports P 1 , P 2 , P 3 , P 4 ; and timer circuitry portion  108 . The timer is programmed to measure a predetermined time interval. During this time interval: (i) light on/off switch  109  remains in the off position so that LED  104  remains off; (ii) circuitry  106  provides electronic control of the mechanical lift components  114 ,  116 ,  120 ,  122  through port P 2 ; and (iii) routine maintenance is not yet required. After the predetermined interval of time passes: (i) circuitry  106  causes an appropriate signal to go out over P 3  to close light on/off switch  109 ; and (ii) when light on/off switch closes, LED  104  receives power and goes on. 
         [0025]    As shown in  FIG. 2 , routine maintenance includes opening up housing  102  from the closed (that is, no-access) position of  FIG. 1  to the open (that is, access) position of  FIG. 2 . In the open position, the maintenance person  130  can access reset timer  110 . In some embodiments a tool may be required to reset the timer without disturbing other components in the controller housing. By manually activating the reset timer mechanism: (i) circuitry  106  causes an appropriate signal to go out over P 3  to re-open light on/off switch  109 ; (ii) when light on/off switch re-opens, LED  104  stops receiving power and goes off; and (iii) clock  108  starts counting another predetermined time interval until the next routine maintenance is called for. The next predetermined time interval may or may not be the same as the first depending upon recommended routine maintenance periods for the type of mechanical lift involved. The cycle of the maintenance LED going on and off and the resetting of timer  108  repeats indefinitely for the whole service life of mechanical lift system  100 . 
         [0026]    In some embodiments of the present invention, connection hardware will not require special tools to remove and may include, for examples: Manually operated latches; screw and nut assemblies; and/or magnetic closures. In other embodiments of the present invention, special tools may be required to manipulate the connection hardware  103  in order to open up controller housing  102 . In some embodiments, the controller housing may not be in the form of housing member  102   a  and removable lid  102   b.  For example, the housing could include a window that is moved between an access and non-access position to selectively provide access to the reset mechanism. As a further example, the reset mechanism could be mounted to the lid (for example, mounted to a circuitry board which is mounted to the lid) so that the access is provided when the lid and reset mechanism are pulled away from the rest of the housing. 
         [0027]      FIG. 3  shows lift system  200  according to the present invention including: lift hardware  202 ; indicator LED  212 ; master controller computer  220 ; and display  222 . Lift hardware includes motor  204 ; drum  206 ; head block assembly  208  and backbone  210 . The indicator LED could alternatively be put in locations other than where it is shown in  FIG. 3 . Preferably, the indicator LED should be placed where it is easy to see and not obscured by lift hardware components. As shown in  FIG. 3 , in addition to the indicator LED, lift  200  also provides visual indication  224  on its display  222 . Display  222  may be, for example, an LCD display. As will be appreciated from  FIG. 3 , it is possible to mechanically connect (see DEFINITIONS section) an indicator to the lift hardware (indicator LED  212  is an example of this), provide an indicator remote to the rest of the lift hardware (indication on display  222  is an example of this), or to do both. 
         [0028]      FIG. 4  shows lift system  300  according to the present invention including: lift hardware  302  and indicator housing assembly  304 . Lift hardware  302  includes motor  310 ; drum  312 ; cable  314 ; backbone  316 ; load sensor  324 ; position sensor  322 ; head block  320 ; and brake  318 . Indicator housing assembly  304  includes: indicator  334 ; reset switch  335 ; lift maintenance detection module  336 ; lift performance limiting module  338 ; and lift control circuitry  340 . Lift maintenance detection module  336  includes: logic sub-module  353 ; timer sub-module  354 ; cycle counter sub-module  352 ; and load counter sub-module  350 . 
         [0029]    Generally speaking, the lift maintenance detection module determines when lift maintenance is required. The load sensor and position sensor provide lift operation data to the lift maintenance detection module for use in detecting when maintenance is required. For example, the cycle counter uses positional data to determine the number of lifting cycles that lift  300  performs. As a further example, the load counter aggregates the lift loading over time to determine lift usage in terms of loading forces exerted over time. The logic sub-module uses one or more of these determinations in combination with the timer to determine when various kinds of maintenance are required and to cause the indicator to indicate that fact to lift users. 
         [0030]    Lift performance limiting module  338  limits lift performance in some way(s) after the lift maintenance detection module determines that it is time for lift maintenance. A non-exhaustive list of possible ways that lift performance may be limited is set forth above in the BRIEF SUMMARY section of this document. In preferred embodiments of the present invention, any lift performance limitations should be both: (i) sufficiently non-intrusive so that theatrical performances can be performed without the audience realizing that any lift performance limitation(s) have occurred; but (ii) sufficiently intrusive so that the lift operator will be motivated to get lift maintenance performed like she should. The performance may become more and more limited over time as the urgency of performing the maintenance increases. 
       Definitions 
       [0031]    The following definitions are provided to facilitate claim interpretation and claim construction: 
         [0032]    Present invention: means at least some embodiments of the present invention; references to various feature(s) of the “present invention” throughout this document do not mean that all claimed embodiments or methods include the referenced feature(s). 
         [0033]    First, second, third, etc. (“ordinals”): Unless otherwise noted, ordinals only serve to distinguish or identify (e.g., various members of a group); the mere use of ordinals implies neither a consecutive numerical limit nor a serial limitation. 
         [0034]    Electrically Connected: means either directly electrically connected, or indirectly electrically connected, such that intervening elements are present; in an indirect electrical connection, the intervening elements may include inductors and/or transformers. 
         [0035]    Mechanically connected: Includes both direct mechanical connections, and indirect mechanical connections made through intermediate components; includes rigid mechanical connections as well as mechanical connection that allows for relative motion between the mechanically connected components; includes, but is not limited, to welded connections, solder connections, connections by fasteners (for example, nails, bolts, screws, nuts, hook-and-loop fasteners, knots, rivets, force fit connections, friction fit connections, connections secured by engagement added by gravitational forces, quick-release connections, pivoting or rotatable connections, slidable mechanical connections, latches and/or magnetic connections). 
         [0036]    Data communication: any sort of data communication scheme now known or to be developed in the future, including wireless communication, wired communication and communication routes that have wireless and wired portions; data communication is not necessarily limited to: (i) direct data communication; (ii) indirect data communication; and/or (iii) data communication where the format, packetization status, medium, encryption status and/or protocol remains constant over the entire course of the data communication. 
         [0037]    Theatrical lift: lifts designed at least primarily for theatrical applications. 
         [0038]    Special tool: a tool not commonly possessed by the average layperson; special tools do not need to be especially designed for a specific lift; for example, an Allen wrench with a square cross-section can be considered as a “special tool.” 
         [0039]    Indicator: any hardware capable of providing an indication to a human or machine, including, but not necessarily limited to visual indications, buzzers, sound indications, etc. 
         [0040]    To the extent that the definitions provided above are consistent with ordinary, plain, and accustomed meanings (as generally shown by documents such as dictionaries and/or technical lexicons), the above definitions shall be considered supplemental in nature. To the extent that the definitions provided above are inconsistent with ordinary, plain, and accustomed meanings (as generally shown by documents such as dictionaries and/or technical lexicons), the above definitions shall control. If the definitions provided above are broader than the ordinary, plain, and accustomed meanings in some aspect, then the above definitions shall be considered to broaden the claim accordingly. 
         [0041]    To the extent that a patentee may act as its own lexicographer under applicable law, it is hereby further directed that all words appearing in the claims section, except for the above-defined words, shall take on their ordinary, plain, and accustomed meanings (as generally shown by documents such as dictionaries and/or technical lexicons), and shall not be considered to be specially defined in this specification. In the situation where a word or term used in the claims has more than one alternative ordinary, plain and accustomed meaning, the broadest definition that is consistent with technological feasibility and not directly inconsistent with the specification shall control. 
         [0042]    Unless otherwise explicitly provided in the claim language, steps in method steps or process claims need only be performed in the same time order as the order the steps are recited in the claim only to the extent that impossibility or extreme feasibility problems dictate that the recited step order (or portion of the recited step order) be used. This broad interpretation with respect to step order is to be used regardless of whether the alternative time ordering(s) of the claimed steps is particularly mentioned or discussed in this document.