Abstract:
A conveying device comprising a conveyor belt, a conveyor belt speed sensor, at least one extending roller selectively extendable from the device, an extending roller speed sensor, a hydraulic motor operatively engaged with the conveyor belt, a proportional valve operatively coupled with the hydraulic motor for modulating the speed of the motor, and a controller operatively connected to the proportional valve for modulating the output thereof, the controller in communication with the belt speed sensor, and in communication with the extending roller speed sensor, the controller thereby controlling the speed of the motor to obtain a desired belt speed.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to conveying devices, and more specifically to vertically adjustable portable conveyors, and particularly to aircraft belt loaders having extendable rollers as well as a conveyor belt. 
   2. Background Information 
   Baggage loading devices are common. A typical device includes a vehicle equipped with an endless belt upon which luggage or other items are placed. Movement of the belt conveys the luggage from one end of the vehicle to the other end. The endless belt may be engaged with a bed that raises or lowers for easier elevational movement of items. Attached to or extended from the endless belt may be a roller or series of rollers. Such extending devices may be retracted to a position beneath the endless belt and may include mechanisms to power the individual conveying rollers. Once extended, the conveying rollers receive items such a luggage or baggage and convey the items to a cargo hold of an aircraft, for instance. The individual roller elements articulate with respect to each other so the items may be transported to a variety of places depending on where the plurality of roller elements is positioned. 
   Applicant has found it desirable to have a conveyor maintain a generally constant or uniform belt speed which matches the speed of the individual extending roller conveyors. Having a matching speed allows items to more smoothly transition from the endless belt to the roller elements, and vice versa. If an operator desires to increase or decrease the speed of the individual extending roller or roller elements, a corresponding increase or decrease would ideally be made to the conveyor belt. Making a corresponding increase or decrease automatically would reduce time and effort of an operator and reduce the risk of mismatched speeds which might otherwise create a hazard or other problems. The present invention provides a novel conveying device and advantages over prior designs. 
   The device includes a control system and a sensing system to automatically adjust the conveyor belt speed of the conveyor, and preferably to adjust the belt speed to match the speed of an extending roller. The device may include a hydraulic system to power the belt, and preferably is configured with an elevating conveyor bed that is affixed to a vehicle. The device is well suited for use in the aircraft cargo loading and unloading industry, or the postal and handling industries. Numerous other advantages and novel features of the present invention are disclosed. 
   SUMMARY OF THE INVENTION 
   The present invention is directed toward a conveying device comprising a conveyor belt, a conveyor belt speed sensor, at least one extending roller selectively extendable from the device, an extending roller speed sensor, a hydraulic motor operatively engaged with the conveyor belt, a proportional valve operatively coupled with the hydraulic motor for modulating the speed of the motor, and a controller operatively connected to the proportional valve for modulating the output thereof, the controller in communication with the belt speed sensor, and in communication with the extending roller speed sensor, the controller thereby controlling the speed of the motor to obtain a desired belt speed. 
   A further aspect of the invention includes a conveying device comprising a portable conveyor bed having a first end and an opposite second end, the conveyor bed tiltable from a resting mode to an incline mode, a conveyor belt operatively engaged with at least one belt roller of the conveyor bed, at least one extending roller selectively extendable from the device and retractable into the device beneath the conveyor belt, an extending roller speed sensor, a hydraulic system including a hydraulic motor operatively engaged with the conveyor belt at the at last one belt roller, and a controller in communication with the extending roller speed sensor and in communication with the hydraulic system, the controller thereby controlling the speed of the motor to obtain a desired belt speed. 
   A further aspect of the present invention includes a conveying device comprising a conveyor belt coupled with an elevating conveyor bed, the conveyor bed connected to a vehicle, means for sensing the speed of the conveyor belt, a plurality of extending rollers selectively extendable from the device, at least one of the extending rollers including a roller, means for sensing the speed of the roller, a hydraulic motor operatively engaged with the conveyor belt, a proportional valve operatively coupled with the hydraulic motor, the proportional valve capable of modulating the speed of the motor; and a controller operatively connected to the proportional valve for modulating the output thereof, the controller in communication with the means for sensing the speed of the conveyor belt, and in communication with the means for sensing the speed of the roller, the controller thereby controlling the speed of the motor to obtain a desired belt speed. 
   The above summary of the present invention is not intended to describe each illustrated embodiment, aspect, or every implementation of the present invention. The figures and detailed description that follow more particularly exemplify these and other embodiments and further aspects of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention may be more completely understood in consideration of the following description of various embodiments of the invention in connection with the accompanying drawings, in which: 
       FIG. 1  is a plan view of a conveyor device made in accordance with the present invention. 
       FIG. 2  is a side elevation view of a conveyor device of the present invention having retractable conveyor retracted and portions of the device removed for clarity. 
       FIG. 3  is a section view of the conveyor of  FIG. 2  with portions removed for clarity. 
       FIG. 4  is a partial top view of the device of  FIG. 3 . 
       FIG. 5  is an elevation view of an extending roller component of the present invention taken along line  5 - 5  of  FIG. 6 . 
       FIG. 6  is a plan view of an extending roller component of the present invention. 
       FIG. 7  is a schematic of one aspect of the present invention. 
   

   While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not necessarily to limit the invention of the particular embodiments or aspects described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention and as defined by the appended claims. 
   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to  FIG. 1 , a conveying device according to the present invention is generally depicted with reference to numeral  20 . In one aspect, conveying device  20  includes a conveyor belt  44  and a retractable conveyor  24 . Retractable conveyor  24  includes a plurality of conveying elements  26  which articulate with respect to adjacent elements  26  and accommodate extension of conveyor  24  into various positions.  FIG. 1  shows conveyor  24  in an extended position. Conveyor  24 , or a number of conveying elements  26 , may be placed within the cargo hold of an aircraft, for instance, for transport of cargo items (cargo not shown). Device  20  may include a docking platform  25  intended to rest within or upon the cargo hold area of an aircraft. A front end conveying element  21  may be positioned on platform  25  when in a retracted state. Conveying element  21  may include handle switches or other controls which operate rollers to assist in the extension or retraction of conveyor  24  from device  20 . As individual conveying elements  26  rotate, cargo placed on conveyor  24  is transported along the extended length of conveyor  24 . Conveyor  24  may be fully or partially extended from device  20  as desired. The speed of rotation of each of the conveying elements  26  may be independently controlled but is preferably constant and uniform from element  26  to element  26  to accommodate for smooth delivery of cargo or packages thereabout. 
   Referring to  FIG. 1  and  FIG. 2 , conveyor belt  44  is positioned with a conveyor bed  27 . Bed  27  is preferably an elevating conveyor bed which raises or lowers in the direction of arrow “A”. Such elevating accommodates delivery of items to an upper area such as a cargo hold or other elevated position. Preferably bed  27  is connected to a vehicle chassis  29 , and is preferably pivotally connected. Chassis  29  is preferably equipped with an engine and wheels  33  for transport.  FIG. 2  shows device  20  with retractable conveyor  24  retracted in a retracted position and located below belt  44 . Portions of the drawing of bed  27  have been removed for clarity. Multiple conveying elements  26  are stored beneath conveyor belt  44  and may be extracted from device  20  by drive means  39 , for instance. 
   Conveyor belt  44  is preferably an endless belt driven by pulleys and/or rollers and typically supported by multiple conveyor belt rollers. While not limited thereto, typically a headstock pulley  34  turns or drives belt  44 , and may do so with the support of other rollers or devices such as a tail stock pulley  35 , return idlers  62  positioned under conveyor bed  27 , and/or top rollers  64  positioned between belt  44 . While preferable, it may be appreciated that the drive system for conveyor belt  44  need not be limited to a headstock pulley  34 . Other rollers or pulleys may be powered to turn belt  44 . Preferably headstock pulley  34  is powered via a hydraulic motor  36  as is well understood. 
   Referring now to  FIG. 3  and  FIG. 4 , close-up views of belt  44  and headstock pulley  34  are shown. Device  20  includes a belt speed sensor means including a belt speed sensor  30  configured adjacent belt  44 . As shown in  FIG. 3  and  FIG. 4 , sensor  30  is configured adjacent or in combination with pulley  34 . It may be appreciated that sensor  30  may be positioned elsewhere along or about device  20  in order to sense a speed of travel of belt  44 . As pulley  34  rotates, belt  44  rotates at an equal or substantially equal rate. Thus, the speed of travel of belt  44  may be calculated by determining the speed of rotation of pulley  34 . In one aspect, speed sensor  30  may include sensor  37  which is positioned adjacent a timing gear  48 . Typically gear  48  is made of metal or has metal parts, and is affixed to rotate together with pulley  34 . Gear  48  includes teeth  49  and gaps  47 . As teeth  49  (or an individual tooth  49 ) passes sensor  37 , an electrical signal or pulse is created or detected and thereafter communicated to a control  70 . The number and timing of pulses or signals is calculated by control  70  to determine a speed of belt  44 . Sensor  30  may include a transducer element or other item capable of detecting the frequency or rate of movement of the individual teeth  49 . Sensor  37   a  is positioned in close proximity to gear  48  in order to detect the movement of rotating teeth  49 . A bracket  23  or other bracket mechanism may be used to hold or properly position sensor  37   a  upon device  20 . Other belt speed sensor means which send a timing signal or other speed data to a controller may also be used without departing from the scope of the invention, including but not limited to optical sensors, transducers, and other types of speed sensors. Sensor means may be positioned at any point along belt  44  or at rollers associated with belt  44 , and need not be limited to a sensor  30  or sensor  37   a  coupled with pulley  34 . 
   Referring now to  FIG. 5  and  FIG. 6 , close-up views of at least one extending roller  26  is shown. In this instance, roller  26  is designated as rear-end extending roller  26   n  representing the terminal extending roller  26   n  of retractable conveyor  24  positioned closest to belt  44  when conveyor  24  is fully extended. Device  20  includes an extending roller speed sensing means. In one aspect, roller  26   n  is equipped with extending roller speed sensor  60 . While extending roller sensor means may be positioned on device  20  at different locations, including but no limited to positioning with an extending roller  26 , such means is preferably associated with the rear-end roller  26   n  so that sensor means, such as sensor  60 , may be protected within or under the conveyor bed  27 . Preferably sensor  60  does not extend from bed  27 . 
   As shown in  FIG. 5 , extending roller  26   n  is equipped with pin or pins  51 . In this instance, pins  51  insert within roller sleeve  32  which is fitted about roller  50 . Other arrangements for fitting of pins  51  may also be used. Preferably, pins  51  are inserted into roller sleeve  32  parallel to the axis of rotation of roller  50  and at generally equal distance with respect to other pins  51 , and preferably close to the exterior surface of sleeve  32 . Typically sleeve  32  may be cut at slit  55  generally at a center portion, the pins  51  may be inserted, and then sleeve  32  repositioned about roller  50 . While pins  51  may be cylindrical, other shapes or configurations may be used. Pins  51  may also be a magnet or magnets. It may be appreciated that the placement of pin  50  is not limited to the configuration shown.  FIG. 6  shows pin  51  inserted into roller sleeve  32  at about the midpoint of roller  26  in the axial direction. It may be appreciated that pins  51  could be inserted at any point along the length of roller  26 . Speed sensor  60  includes pin  51  and sensor  37   b . Speed sensor  37   b  may be mounted to plate  53  with bracket  25  or other positioning item. Preferably sensor extends to a position adjacent roller  50  so as to detect pin  51  as roller  50  turns. As pin  51  turns or passes sensor  37   b , an electrical signal or pulse is created or detected and thereafter communicated to a control  70 . Sensor  60  may include a transducer element or other item capable of detecting the frequency or rate of movement of the individual pins  51 . Other means for sensing the speed of roller  50  or conveying roller  26  which send a timing signal or other speed data to a controller may also be used without departing from the scope of the invention, including but not limited to optical sensors, transducers, and other types of speed sensors. Sensor means may be positioned at any point along or about retractable conveyor  24  or extending rollers  26 , and need not be limited to a sensor  30  or sensor  37   b.    
     FIG. 7  is an operational schematic depicting on aspect of conveying device  20 . Device  20  includes a hydraulic system and the speed control system. A system controller device  70  is operatively connected to belt speed sensor  30  via signal line  46   a , and to roller speed sensor  60  via signal line  46   b . Controller  70  is also operatively connected to proportional valve  43  via signal line  45 . It may be appreciated that controller  70  may be operatively connected to sensor means via an electrical line, radio signal, light signal, or other means of sending or receiving data. The controller device  70 , typically an integrated circuit device or computer, calculates the speed of conveyor belt  44  and extending rollers  26  based on the outputs from the respective speed sensors  30 ,  60 . If there is a change in speed at rollers  26 , control  70  detects the change and may react by sending a signal to solenoid  54  coupled to proportional valve  43  via signal line  45 . This signal will cause proportional valve  43  to either increase or decrease the flow of hydraulic fluid to hydraulic motor  36 , which will alter the speed of hydraulic motor  36 . The drive system of conveyor belt  44  is powered by hydraulic motor  36  and this change in speed will either increase or decrease the speed of belt  44 . 
   The control  70  may be programmed to recognize  4  pulses of the pins  51  to equal one revolution of roller  50 , and this data is used in conjunction with the diameter measure of the roller to determine or calculate the extending roller speed. It may be appreciated that other sensor means may be used. 
   In further reference to  FIG. 7 , hydraulic motor  36  may be a constant speed hydraulic motor with a pump  56  which pumps fluid from tank  58 . Excess fluid spills through a relief valve from pump  56  back to tank  58  as needed. Other relief valves may be included as desired in such a hydraulic system. A directional valve  66  may be used to control forward or reverse direction of motor  36  which in turn reverses direction of hydraulic flow and of belt  44  as desired. 
   In operation, controller  70  may be preprogrammed (or programmed or switched on demand) to have the speed of belt  44  match the speed of rollers  26 , and vice versa. If an operator desires to increase the speed of rollers  26 , the speed of belt  44  automatically increases. Preferably the speed of belt  44  and speed of rollers  26  is a matching speed, and continues to be a matching speed even after changing either the speed of belt  44  or the speed of roller  26   n . While greater or lesser speeds may be achieved, in a typical baggage transport operation a roller speed and belt speed of between approximately 60 feet to 75 feet per minute may be established. An operator may set the speed of rollers  26  and may vary such speeds in a variety of ways, such as through use of changes in voltages or frequencies or other methods. A controller may be modified or manipulated with use of a computer to adjust the roller speed as desired. Control  70  may include an integrated circuit and/or readable and/or programmable memory or is otherwise a programmable controller. 
   The terms and descriptions used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention as defined in the following claims, and their equivalents, in which all terms are to be understood in their broadest possible sense unless otherwise specifically indicated. While the particular CONVEYOR WITH ROLLER TO BELT SYNCHRONIZATION MECHANISM as herein shown and described in detail is fully capable of attaining the above-described aspects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and thus, is representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. section 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.”