Positionable Loading Rack and Method for Safely Moving a Load

Abstract

Embodiments include a loading rack apparatus mountable on a vehicle having a hoist motor, an extendable horizontal trolley to permit a load to be lifted with the hoist, moved horizontally into a vehicle, and lowered. A variety of embodiment trolley drive mechanisms are disclosed including but not limited to a rack-and-pinion means, belt drive means, and a lead screw means. A control means prevents trolley and hoist motor overcurrent. The control means includes a plurality of safety features including a tilt detection means to avoid loading under unsafe conditions and a pressure sensitive switch to halt trolley movement if the trolley contacts an object or person. A DC motor control means provides button control for trolley and hoist motors and emergency cut off. The top surface is shaped to define a surface for items. An arcuate embodiment crossbar member permits more stable positioning of items on the apparatus's topmost surface. A method for safely moving a load is disclosed.

We claim: 
     
         1 . A vehicle mounted loading rack apparatus comprising:
 a vertical support structure, wherein a portion of said structure makes contact and rests upon a vehicle;   a horizontal member affixed to said vertical support structure;   a trolley disposed substantially in the same plane as said horizontal member, reversibly extendable from said horizontal member;   a hoist motor mounted on a relatively rearward portion of said trolley;   a trolley drive means for reversibly extending said trolley relative to said horizontal member;   wherein said hoist motor may be actuated to lift a load vertically relative to the ground,   wherein said trolley drive means, when actuated, may move the lifted load horizontally relative to the ground, toward the vehicle, wherein the load may be lowered onto a vehicle.   
     
     
         2 . The loading rack apparatus of  claim 1 , wherein said trolley drive means is mounted on a relatively frontward portion of said trolley. 
     
     
         3 . The loading rack apparatus of  claim 2 , wherein said horizontal member comprises a pair of twin rails affixed to a plurality of support webs, wherein said trolley drive means is rack-and-pinion system that comprises: a motor, said motor mounted on said trolley; a driveshaft operably coupled to said motor, wherein said motor may rotatably drive the driveshaft, a pair of pinion wheels fixed upon either end of said driveshaft, a drive rack bearing grooves securably affixed to the surface of at least one of the pair of rails, wherein said pinion wheels may registerably engage said rack, wherein rotation of said wheels drives the trolley. 
     
     
         4 . The loading rack apparatus of  claim 2 , wherein said trolley drive means is a belt drive system comprising: a motor, said motor mounted on said trolley; a driveshaft operably coupled to said motor, wherein said motor may rotatably drive the driveshaft, a pulley wheel fixed upon either end of said driveshaft; a belt anchored to said horizontal member in a relatively forward and rearward location, a first and a second belt idler affixed to said trolley, wherein said anchored belt engages the first belt idler, engages a portion of said pulley wheel, and engages the second belt idler; a front and a rear load wheel affixed to said trolley and freely rotatable thereupon, wherein pulley wheel engages said belt, wherein rotational motion of said pulley wheel drives the trolley. 
     
     
         5 . The loading rack apparatus of  claim 1 , wherein said trolley drive means is mounted on a relatively frontward portion of said horizontal member, wherein said drive means is a lead screw drive means comprising: a motor, said motor mounted on said horizontal member; a driveshaft operably coupled to said motor, wherein said motor may rotatably drive the driveshaft, a first bevel gear upon either end of said driveshaft; a second bevel gear oriented at 90 degrees relative to and registering with the first bevel gear; a lead screw having a first end and second end, the first end of said lead screw affixed to said second bevel gear, a cylindrical guide affixed to said trolley, said guide having an inner threading, wherein the lead screw passes through and screwably engages said guide, wherein said rotation of driveshaft rotates said first and second bevel gear and said lead screw, wherein the trolley is driven longitudinally. 
     
     
         6 . The loading rack apparatus of  claim 1 , further comprising at least two crossbars affixed to said vertical support structure; 
     
     
         7 . The loading rack apparatus of  claim 6 , wherein said crossbars are arcuately shaped. 
     
     
         8 . The loading rack apparatus of  claim 1 , wherein said sides are formed of extruded aluminum, wherein said sides are shaped to define a wheel guide and at least one attachment port. 
     
     
         9 . The loading rack apparatus of  claim 1 , further comprising an overcurrent detection means to protect the hoist motor and the trolley motor, said means comprising: a hall-effect integrated circuit electrically connected to said hoist motor, an operational amplifier electrically connected to said hoist motor and receiving current therefrom, wherein said operational amplifier conditions said output signal; a microcontroller having a plurality of analog-to-digital converter input pins, wherein said microcontroller is electrically coupled to said operational amplifier wherein said current may be sensed by said microcontroller; a hall-effect integrated circuit electrically connected to said trolley motor, an operational amplifier electrically connected to said trolley motor and receiving current therefrom, wherein said operational amplifier conditions said output signal; a microcontroller having a plurality of analog-to-digital converter input pins, wherein said microcontroller is electrically coupled to said operational amplifier wherein said current may be sensed by said microcontroller, said microcontroller being programmed with a predetermined threshold value, wherein if said value is reached, current flowing to the motor is disconnected or stopped. 
     
     
         10 . The loading rack apparatus of  claim 1 , further comprising an overtilt detection means to provide safe apparatus operation, said means comprising: an accelerometer electrically connected to an operational amplifier, wherein said operational amplifier provides signal conditioning, a microcontroller having at least one analog-to-digital converting input, wherein said output from the operational amplifier is electrically connected to said analog-to-digital converting input pin, wherein said current may be sensed by said microcontroller, said microcontroller being programmed with a predetermined threshold value, wherein if said value is reached, current flowing to the motor is disconnected or stopped. 
     
     
         11 . The loading rack apparatus of  claim 1 , further comprising a safety sensing means to avoid injury, said means comprising: a pressure actuated tape switch mounted on the outer aspect of said trolley and electrically connected to said trolley drive means, wherein when said tape switch is actuated, current flowing to the trolley drive means is disconnected or stopped. 
     
     
         12 . The loading rack apparatus of  claim 1 , further comprising a DC motor controlling means to provide forward and reverse trolley movement, and up and down movement of said hoist motor and an emergency stop, said means comprising: a plurality of switches permitting bidirectional motor actuation to drive said trolley forward or rearward, a plurality of switches permitting bidirectional hoist motor actuation permitting the hoist motor to raise or lower a load, at least one emergency switch, wherein said dwitch is normally-closed, wherein actuation of said switch will stop or disable all motor movement; a five switch pendant interface electrically connected to said switches. 
     
     
         13 . The loading rack apparatus of  claim 1 , wherein said horizontal member has a front support and sides, wherein said sides are formed of extruded aluminum, wherein a portion is shaped to define a wheel guide, a portion is shaped to define a lead screw recess, a T-slot accessory recess, and a plurality of attachment points. 
     
     
         14 . The loading rack apparatus of  claim 1 , wherein said horizontal member has a front support and sides, wherein said sides are formed of extruded aluminum, wherein a portion is shaped to define a single wheel recess, a portion is shaped to define a lead screw recess. 
     
     
         15 . A vehicle mounted loading rack comprising:
 a vertical support structure having a bed rail affixed to vertical support members, wherein said bedrail is in contact with the sides of a truck bed, and wherein said vertical support members extend relatively vertically from said bed rail;   a plurality of utility posts slidably disposed within the terminal aspect of said vertical support structure;   a horizontal member having sides and front defining corners, wherein sides of said horizontal member affixed to said vertical supports, wherein said sides formed of extruded aluminum and shaped to define a wheel guide and a lead screw recess;   a plurality of arcuate crossbar assemblies, wherein said plurality comprises a middle crossbar assembly and rear crossbar assembly disposed upon said utility posts and a front crossbar assembly affixed to said horizontal member;   a trolley having a front end and rear end, an end truck attached to said rear end, a pair of wheels mounted on said trolley and freely rotatable thereupon, wherein said wheels engage said wheel guide of said horizontal member, at least two cylindrical lead screw guides located on the outside edges of said trolley, wherein said guides have an internal threading;   a hoist motor mounted on the end truck;   a trolley motor mounted on a relatively front portion of said horizontal member;   a drive shaft operatively coupled to said motor, wherein said drive shaft is rotatably driven by said motor;   a first bevel gear located at the terminal end of said driveshaft;   a second bevel gear registering with said first gear;   a lead screw having a first end, said lead screw coupled to the second bevel gear at the first end, wherein said lead screw passes through said cylindrical lead screw guides, threadably engaging said guide;   wherein upon motor actuation, said motor drives said drive shaft to turn the first and second bevel gear, said lead screw is rotated, said rotated screw engaging internal threading of said cylindrical lead screw drive, driving trolley linearly relative to said horizontal support along trolley wheels to permit trolley extension and retraction of relative to said horizontal support;   a motor control means electrically coupled to said motor, said means comprising a current measuring means, wherein said means comprises a first Hall-effect integrated circuit electrically coupled to said hoist motor, and a second Hall-effect integrated circuit coupled to said trolley motor, wherein said hoist motor current and trolley motor current are measured, said first and second circuit each having an output;   a microcontroller, having a plurality of analog-to-digital converter input pins, said microcontroller operatively coupled to said first and second Hall-effect integrated circuit output wherein said output for each motor is electrically connected said analog-to-digital pin, wherein said output current may be sensed by said microcontroller and compared to a threshold value;   a tilt sensor, wherein said tilt sensor comprises a three axis accelerometer, wherein said output is electrically coupled to one of the plurality of microcontroller analog-to-digital converter inputs;   a plurality of input switches, wherein said plurality includes a plurality of tape switch inputs and a plurality of limit switches;   a plurality of DC motor control switches, wherein said plurality includes four-way directional movement switches, and an emergency stop switch;   a control pendant electrically coupled to said motor control switches, wherein said pendant has a four-way directional buttons and an emergency stop button.   
     
     
         16 . A method of safely loading a load comprising:
 identifying a load to be moved; providing a truck mounted apparatus having a vertical support structure, wherein a portion of said structure makes contact and rests upon a vehicle; a horizontal member affixed to said vertical support structure; a trolley disposed substantially in the same plane as said horizontal member, reversibly extendable from said horizontal member; a hoist motor mounted on a relatively rearward portion of said trolley; a trolley drive means for reversibly extending said trolley relative to said horizontal member; an overcurrent detection means to protect the hoist motor and the trolley motor; an overtilt detection means to provide safe apparatus operation; comprising a safety sensing means to avoid injury; a DC motor controlling means to provide forward and reverse trolley movement, and up and down movement of said hoist motor and an emergency stop; attaching said load to said apparatus; actuating said hoist motor sufficient to raise said load above the highest level of the truck where said load is to be positioned; actuating said trolley motor in a frontward direction, wherein said trolley with hoisted load is moved horizontally toward to front of said truck; stopping said trolley motor when desired horizontal position is reached; actuating said hoist motor to lower said apparatus into desired position.