Abstract:
A toy workover rig modeling the kind used to service oil and gas wells. The workover rig includes a wheeled truck. An extensible mast is pivotally fastened to the truck. A remotely-controlled pivoting assembly is connected to the truck for selectively moving the mast from a horizontal, traveling position to a vertical, substantially perpendicular operating position. A remotely-controlled telescoping assembly is connected to the truck for selectively extending the mast from a retracted position to an extended position. A remotely-controlled hoisting assembly is connected to the truck for lifted selected objects within the mast.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to amusement devices having means to draw or pull. 
     BACKGROUND OF THE INVENTION 
     One common piece of heavy equipment used to produce hydrocarbons from the earth is referred to as: a workover rig, a completion rig, or a pulling unit. Such a thing can do many tasks, but it is primarily used to hoist damaged tubing from a well and lower undamaged tubing into a well so that oil and gas can flow more freely. A workover rig can also be used to “complete,” repair, or swab a well to maximize its rate of fluid production. 
     A workover rig comprises a truck carrying a telescoping mast and a winch. In use, the truck is backed up to a well, the mast is raised, and the lifting of tubing is initiated using the winch. A typical, workover rig is used only during daylight hours. A workover rig cannot drill into the earth unless equipped with a special “power swivel” that moves up and down while turning drill pipe extending into the well. 
     Thousands of men in the United States work upon workover rigs and are interested in workover rigs. It is believed that many would like to own a functioning model of such a rig. Duplicating every feature of a workover rig in a mass-produced model, however, is not practical since many features would be tiny and especially costly to make. Changes are necessary in the various apparatus that: pivots the mast to its substantially perpendicular, upright orientation, telescopes the mast to its full length, and hoists tubing. 
     SUMMARY OF THE INVENTION 
     In light of the problems associated with replicating a full-size workover rig at a small scale, it is a principal object of the invention to provide a toy workover rig with means for pivoting, telescoping, and hoisting that are lifelike in operation if not exact in appearance. 
     It is another object of the invention to provide a toy workover rig of the type described that is radio controlled. A person with minimal experience can operate the toy workover rig without resort to prolonged training, study aids, or additional tools. An oil and gas operator can even employ my toy workover rig during a new hire&#39;s orientation session to provide a familiarity with a rig&#39;s working parts and function. 
     It is an object of the invention to provide improved elements and arrangements thereof in a toy workover rig for the purposes described which is lightweight in construction, inexpensive to make, and fully dependable in use. 
     The toy workover rig in accordance with this invention achieves the intended objects by featuring an extensible mast that is pivotally fastened to a wheeled truck. A remotely-controlled pivoting assembly is connected to the truck for selectively moving the mast from a horizontal, traveling position to a vertical, operating position. A remotely-controlled telescoping assembly is connected to the truck for selectively extending the mast from a retracted position to an extended position. A remotely-controlled hoisting assembly is connected to the truck for lifted selected objects within the mast. 
     The foregoing and other objects, features and advantages of my toy workover rig will become readily apparent upon further review of the following detailed description of the preferred embodiment illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       My invention is more readily understood with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a toy workover rig having its mast elevated and telescoped upwardly. 
         FIG. 2  is a side elevational view of the workover rig of  FIG. 1  having its mast elevated and extended upwardly. 
         FIG. 3  is a rear elevational view of the workover rig with portions broken away to reveal details of the telescoping assembly. 
         FIG. 4  is a perspective view of the rear portion of the workover rig with portions being broken away to reveal details of the hoisting assembly. 
         FIG. 5  is a perspective view of the central portion of the mast of the workover rig with the tubing board being shown in an extended position. 
         FIG. 6  is a perspective view of the central portion of the mast of the workover rig with the tubing board being shown in a retracted position. 
         FIG. 7  is a perspective view of the upper portion of the mast of the workover rig with the rod basket being shown in an extended position. 
         FIG. 8  is a perspective view of the central portion of the mast of the workover rig with the rod basket being shown in a retracted position. 
         FIG. 9  is an enlarged front elevational view of the traveling block of the workover rig. 
         FIG. 10  is a schematic diagram of the electrical circuit for the workover rig. 
         FIG. 11  is a schematic diagram of a transmitter of the workover rig featuring a three-channel remote control with joysticks. 
     
    
    
     Similar reference characters denote corresponding features consistently throughout the accompanying drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the FIGS., a toy workover rig in accordance with the present invention is shown at  10 . Workover rig  10  includes a truck  12  that carries an extensible mast  14  at its rear. Mast  14  can be selectively moved from a horizontal, traveling position to a substantially perpendicular, vertical, operating position by a pivoting assembly  16 . A telescoping assembly  18  is employed to selectively extend mast  14  to its full height. A hoisting assembly  20  selectively lifts a joint of tubing  22  within mast  14 . Assemblies  16 ,  18  and  20  of the rig  10  are operated by remote control. 
     Truck  12  includes an elongated body  24  that is supported above the ground by a number of rotatable wheels  26 . A cab  28  is affixed to the front of body  24 . A pair of upright braces  30  is affixed to the rear of body  24  for pivotally securing mast  14  thereto. Each of braces  30  has a diagonal member  32  and a vertical member  34  being connected together so as to form an inverted V-shape. The tops of braces  30  are positioned at a height that is somewhat greater than that of cab  28  and carry hinges  36  to which mast  14  is pivotally connected. A mast support  38  is affixed to body  24  behind cab  28  for holding mast  14  above cab  28  when mast  14  is pivoted downward for safe movement of workover rig  10  from place to place. A dummy motor  40  is affixed to body  24  adjacent support  38 . 
     Body  24  is provided with a number of ground-engaging stabilizers  42  and  44  to prevent it from tipping when mast  14  is pivoted substantially perpendicular upright and telescoped. A pair of center stabilizers  42  is provided at the midpoint of body  24  with one being located on each side of body  24 . Each of stabilizers  42  has a guide sleeve  46  in the bottom of body  24  and an arm  48  that fits snugly, yet slidably, within sleeve  46 . Each sleeve  46  is configured such that, when a moderate pushing or pulling force is applied to the associated arm  48 , arm  48  is moved within sleeve  46  along an axis that extends downwardly and outwardly from body  24 . When fully extended, each arm  48  contacts the ground at a point that is not beneath body  24  thereby preventing body  24  from tipping sideways. Additionally, a pair of rear stabilizers  44  is provided at the rear of body  24  with one being located on each side of body  24 . Each stabilizer  44  has a vertically oriented, guide sleeve  50  in the bottom of body  24  that is internally, helically threaded. A helically threaded rod  52  is screwed into each sleeve  50 . When screwed outwardly, each rod  52  is brought into contact with the ground beneath body  24  preventing body  24  from tipping rearwardly. 
     A draw works housing  54  is affixed to the top of body  24  between simulated motor  40  and braces  30 . Housing  54  is a substantially rectangular box, being defined by: a front wall  56 , a rear wall  58 , a pair of opposed side walls  60 , and a top wall  62 . Top wall  62  is hingedly attached to front wall  56  for full access to the interior of housing  54  from above. The top of the rear wall  58  and the rear of the top wall  62  are provided with large openings as at  64  for access to components installed within housing  54  and described hereinbelow. 
     Housing  54  carries several joints of tubing  22  for lifting by rig  10 . Two columns of hooks (not shown) are affixed to one of side walls  60  so that the hooks of each column have horizontally positioned counterparts in the other column. The columns are set at a distance apart that is somewhat less than the length of a joint of tubing  22 . Removably positioned on each pair of horizontally spaced hooks is a joint of tubing  22 . 
     Mast  14  includes a bottom section  14   b  and a top section  14   t  that are slidably connected together. Bottom section  14   b  has a U-shaped cross section with a base truss  66  connecting together a pair of lateral trusses  68   r  and  68   l . Each lateral truss  68   r  and  681  has, extending along the length of its rear side, an inwardly facing, guide bar  70  that serves to slidably retain top section  14   t  within the confines of bottom section  14   b . A tubing board rest  72  extends rearwardly from each guide bar  70  about midway along its length. Hinges  36  pivotally connect the bottom of base truss  66  to diagonal members  32 . 
     A ladder  76  is affixed to, and extends along, truss  68   l . Beneath ladder  76 , an operator&#39;s platform  78  is pivotally fastened to truss  68   l . Platform  78  has a pair of pegs  80  that carry a detachable handrail  82 . Handrail  82  has a pair of pins  84  at its bottom that can be inserted into a pair of tight-fitting sockets (not shown) in the outer edge of platform  78 . When mast  14  is pivoted substantially perpendicular upright, platform  78  is manually pivoted to a horizontal orientation and pins  84  are inserted into the sockets to hold the handrail  82  in a vertical orientation. 
     A work floor  86  is pivotally connected to bottom section  14   b . Work floor  86  comprises a U-shaped plate  88  having a pair of ground engaging legs  90  hingedly fastened thereto. One of a pair of hinges  92  pivotally connect the front of plate  88  to the bottom of lateral truss  681  and the other of hinges  92  pivotally connects the front of plate  88  to the bottom of lateral truss  68   r . A cutout (not shown) in the front of plate  88  between hinges  92  provides additional ground access for traveling block  94  and items carried thereby. When mast  14  is pivoted substantially perpendicular upright, plate  88  is manually pivoted to a horizontal orientation to the rear of mast  14  and legs  90  are pivoted downwardly to a vertical orientation to engage the ground and retain plate  88  in a horizontal orientation. 
     The top section  14   t  of mast  14  has a U-shaped cross section being somewhat smaller than that of bottom section  14   b  so that top section  14   t  can slide easily therein. Top section  14   t  has a base truss  96  adapted for slidable positioning against base truss  66 . Base truss  96  carries a ladder  98  and connects together a pair of lateral trusses  100   r  and  100   l  adapted for slidable positioning against lateral trusses  68   r  and  68   l . Each lateral truss  100   r  and  100   l  has a tubing board brace  102  affixed to, and extending rearwardly from, the bottom thereof. A pulley  104  is mounted atop each tubing board brace  102 . Above each tubing board brace  102  and remote from pulley  104 , a rod basket brace  106  is affixed to, and extends rearwardly from, each lateral truss  100   r  and  100   l.    
     A crown  108 , having a rectangular frame  110 , is affixed to the top of top section  14   t . Frame  110  has a pair of side members  112   a  and  112   b  that serve as upward extensions of lateral trusses  100   r  and  100   l . A pair of cross members  114   a  and  114   b , positioned side-by-side, connect the tops of side members  112   a  and  112   b  together. A cylindrical shaft  116  connects side members  112   a  together. A brace bar  118  connects side members  112   b  together. A stub shaft  120  is affixed between shaft  116  and brace bar  118 . 
     Crown  108  has a number of pulleys  122   l ,  122   r  and  124 . A forward pair of pulleys  122   l  and  122   r  is rotatably secured upon shaft  116  in a side-by-side relationship. A medial pulley  124  is rotatably secured to stub shaft  120  and is positioned to rotate without interference from pulleys  122   l  and  122   r . Pulleys  122   l ,  122   r  and  124  assist in the raising and lowering of traveling block  94 . 
     A rearward pair of pulleys  104  is rotatably secured to brace bar  102  by a pair of support brackets  126 . Pulleys  104  rotate independently of one another and assist in the raising and lowering of a tubing board  128  and rod basket  130  described hereinbelow. 
     Tubing board  128  is pivotally connected to top section  14   t  and extends rearwardly from it. Tubing board  128  has a U-shaped retainer  132  that is pivotally connected at its front to tubing board braces  102 . Affixed to the rear of retainer  132  are a number of forwardly facing tines  134  that define spaces therebetween for racking pieces of tubing  22  lifted by traveling block  94 . One of a pair of handrails  136  is rigidly affixed to each of the opposite sides of retainer  132 . For compact storage when mast  14  is pivoted downwardly onto mast support  38 , another handrail  138  is pivotally secured at its bottom to the rear of retainer  132 . 
     Rod basket  130  is pivotally connected to top section  14   t  and extends rearwardly from it. Rod basket  130  has a U-shaped retainer  140  from which a basket member  142  is suspended by its U-shaped top rail  144 . For compact storage, retainer  140  is pivotally connected at its front to rod basket braces  106  and the rear of top rail  144  is pivotally connected to the rear of retainer  140 . (The front of retainer  140  is open and configured in a manner that prevents retainer  140  from pivoting to a position more than a few degrees beyond horizontal when mast  14  is pivoted to an upright, substantially perpendicular position.) Extending sideways from the front of top rail  144  is a pair of retaining pins  146  that abut the top of retainer  140  and maintain basket member  142  in an upright, substantially perpendicular position when the mast  14  is pivoted substantially perpendicular upright. 
     Pivoting assembly  16  operates to swing mast  14  substantially perpendicular upright on hinges  36 . Pivoting assembly  16  includes an electric motor  148  mounted atop truck body  24  between braces  30 . Motor  148  drives a gearbox  150  that effectively increases torque. Gearbox  150  has a horizontal driveshaft  152  that is rotated by motor  148 . 
     Pivoting assembly  16  has a lever arm  154  that is affixed at its bottom end to driveshaft  152  and projects outwardly from driveshaft  152 . Lever arm  154  is also affixed to the periphery of a gear  156  being part of gearbox  150 . Thus, when the gear  156  and driveshaft  152  are caused to rotate by the operation of motor  148 , lever arm  154  moves in concert with them. 
     A link  158  is affixed to the free end of lever arm  154  remote from drive shaft  152 . Link  158  has a pair of lateral plates  160  that extend from lever arm  154 . Link  158  also has a cross pin  162  that connects lateral plates  160  together at a location remote from lever arm  154 . 
     Pivoting assembly  16  has a guide rail  164  affixed to base truss  66 . Guide rail  164  extends along the length of base truss  66  and is positioned at its center. Guide rail  164  is approximately ⅓ the length of base truss  66  and is positioned midway between the ends of base truss  66 . Guide rail  164  has a longitudinal slot  166  that extends from one of its ends to the other. Cross pin  162 , carried at the free end of lever arm  154 , is positioned within slot  166  where it freely slides. 
     When motor  148  is energized to run in a “positive” direction, gear  156 , driveshaft  152  and lever arm  154  are caused to rotate in a clockwise direction as seen in  FIG. 2 . Cross pin  162 , then, presses against guide rail  164  from its position within slot  166  thereby pivoting mast  14  upwardly on hinges  36 . The continued operation of motor  148  raises mast  14  to a vertical orientation with cross pin  162  pressing against guide rail  164  and sliding along the length of slot  166 . Returning mast  14  to its starting position is a simple matter and is accomplished merely by reversing the polarity of the electrical current sent to motor  148 . With motor  148  now running in a “negative” direction, gear  156 , driveshaft  152 , and lever arm  154  are rotated in a counterclockwise direction as seen in  FIG. 2  thereby pivoting mast  14  downwardly. 
     Telescoping assembly  18  operates to lift top section  14   t  above bottom section  14   b  when mast  14  is swung to an upright orientation by pivoting assembly  16 . Telescoping assembly  18  includes an electric motor  168  affixed to the bottom of bottom section  14   b  between lateral trusses  68   r  and  68   l . Motor  168  drives a gearbox  170 , also affixed to the bottom of bottom section  14   b , having two meshing gears for transmitting power from the motor  168  to a driveshaft  172  extending upwardly from the gearbox  170 . 
     Telescoping assembly  18  has a jackscrew  174 . Jackscrew  174  is a helically threaded rod that extends the length of bottom section  14   b . The bottom of jackscrew  174  is affixed to the top of driveshaft  172  and rotates therewith. 
     Assembly  18  is completed with a jackscrew receiver  176 . Receiver  176  has an elongated tube  178  that is positioned within top section  14   t  for registration with jackscrew  174 . Tube  178  extends the length of top section  14   t  of mast  14 . The top of tube  178  is affixed to the top of top section  14   t  by a cross brace  180  extending between lateral trusses  100   r  and  100   l . The bottom of tube  178  is positioned below tubing board braces  102 . An internally threaded fitting  182  is firmly affixed to the bottom of tube  178 . Into fitting  182 , jackscrew  174  is selectively turned. 
     When motor  168  is energized to run in a “positive” direction, driveshaft  172  and jackscrew  174  rotate counterclockwise when considered from above in  FIG. 3 . Fitting  182 , being kept from rotating by tube  178 , rides upwardly on jackscrew  174  imparting a lifting force through tube  178  and cross brace  180  to the top of mast  14 . The continued operation of motor  168  elevates top section  14   t  to it operating position above bottom section  14   b . 
     Returning top section  14   t  to its starting position within bottom section  14   b  is simple and is accomplished merely by reversing the polarity of the electrical current sent to motor  168 . With motor  168  now running in a “negative” direction, driveshaft  172  and jackscrew  174  are rotated in a clockwise direction as seen from above in  FIG. 3  thereby pulling fitting  182  and, hence, top section  14   t  downwardly. 
     A user of workover rig  10  can easily distinguish when top section  14   t  has reached the upper limit of its travel. The first and easiest way to make such a determination is to see that the top portions of trusses  66 ,  68   r  and  68   l  and the bottom portions of trusses  96 ,  100   r  and  1001  line up horizontally. Another way involves an examination of tubing board  128  and rod basket  130 . Their principle features should extend horizontally and vertically so that it is substantially perpendicular. 
     Tubing board  128  and rod basket  130  are tied to a pair of cords  184  that automatically extend them away from top section  14   t  for use or retract them onto top section  14   t  for storage and transport. Cords  184  extend from the top of bottom section  14   b  through crown  108  and rod basket  130  to tubing board  128 . Cords  184  have a length sufficient to hold tubing board  128  horizontal when top section  14   t  is fully extended from bottom section  14   b . Cords  184  also have a length sufficient to hold tubing board  128  against top section  14   t  with handrails overlapping and enclosing lateral trusses  68   r  and  68   l  when top section  14   t  is retracted within bottom section  14   b.    
     Each of cords  184  touches tubing board  128  in two places. First, each of cords  184  is tied to the rear of retainer  132 . Each of cords  184  extends upwardly from retainer  132  to the top of handrail  138  where it is also connected. Thus, when tubing board  128  is pivoted against top section  14   t  when mast  14  is reduced in length, handrail  138  is pulled flat against top section  14   t  and parallel with retainer  132 . 
     Each of cords  184  contacts rod basket  130  at the rear of retainer  140  near its point of connection to basket  130 . The cords  184  slide through socket members  186  on opposite sides of the retainer  140  in their passage from the top of handrail  138  to pulleys  188 . A knot  190  is provided on each of the cords  184  between handrail  138  and socket member  186  so that, when cords  184  are pulled tight by moving top section  14   t  into bottom section  14   b , knots  190  engage the bottom of retainer  140  to pull it flush against top section  14   t . Basket  130 , being free to pivot relative to retainer  140 , swings compactly into top section  14   t  between lateral trusses  100   r  and  1001  and against elongated tube  178 . 
     Pulleys  188  on opposite sides of workover rig  10  receive cords  184 . As shown, cords  184  run under pulleys  124  and over pulleys  188 . Pulleys  124  and  188  prevent cords  184  from binding and tangling while top section  14   t  is being extended or retracted from bottom section  14   b.    
     Hoisting assembly  20  includes a traveling block  94  having a housing  192  with a pair of hexagonal side walls  194  connected together by: a top wall  196 , an upper front wall  198 , a lower front wall  200 , an upper back wall  202 , and a lower back wall  204 . Top wall  196  is provided with a number of openings  206  for the passage of a tubing line  208 , formed from light rope, into and out of housing  192 . Housing  192  has an opening  210  at its bottom. 
     An axle  212  connects the centers of side walls  194  together and is affixed at its opposite ends to side walls  194 . Positioned in a spaced-apart relationship on axle  212  is a pair of pulleys  214  capable of independent rotation. As shown, tubing line  208  is extended into housing  192  through openings  206  and is wound around pulleys  214 . 
     A bell hanger rod  216  is positioned in the opening  210  of housing  192  beneath axle  212 . Rod  216  connects the bottoms of side walls  194  together. Rod  216  is affixed at its opposite ends to side walls  194 . 
     Traveling block  94  has a pair of connecting rods or bells  218  suspended from it. Each of the bells  218  has a rod portion  220  at its center and an integral loop  222  affixed to the top of rod portion  220  and an integral loop  224  affixed to the bottom of rod portion  220 . Each loop  222  is large enough for the free passage of rod  216  thereby permitting a large degree of pivoting and twisting motion of bells  218  on rod  216 . 
     A hook  226  is suspended from rod  216  between bells  218 . Hook  226  can be employed to catch and suspend miscellaneous tools used with rig  10 . Optionally, hook  226  may incorporate a swivel mechanism  228  to permit it to rotate in any direction relative to rod  216 . 
     From bells  218 , an elevator  230  is suspended. Elevator  230  has a pair of C-shaped jaws  232  and  234  that are pivotally connected together by a pivot pin  236  to form a ring that can be selectively opened and closed to grasp a joint of tubing  22 . To facilitate the opening and closing of the ring, a handle or horn  238  is affixed to each of jaws  232  and  234  remote from pivot pin  236 . Between each horn  238  and the pivot pin  236 , a hanger bar  240  is affixed to each jaw  232  and  234 . Each bar  240  is configured to be extended through a bell loop  224  and is further configured at its outer end to receive a cotter pin  242  to prevent a bar  240  from being disengaged from a loop  224  once inserted therein. A magnet  244  is provided in the free end of jaw  232  and a piece of steel  246  is provided in jaw  234 . When the free ends of jaws  232  and  234  are pivoted together, the attraction of the magnet  244  to the piece of steel  246  tends to keep jaws  232  and  234  closed. A light pull in opposite directions on horns  238 , however, is sufficient to open jaws  232  and  234 . 
     Hoisting assembly  20  operates to move traveling block  94  up and down within mast  14 . To this end, assembly  20  includes a pair of mounting plates  300  and  302  affixed to truck body  24  within housing  54 . Plates  300  and  302  are vertical, parallel to side walls  60 , and spaced away from side walls  60 . An electric motor  248  is affixed to plate  302  between plate  302  and the adjacent side wall  60 . Motor  248  drives a gearbox  304  also affixed to plate  302 . Gearbox  304  has two meshing gears  306  and  308  for the transmission of power. The large gear  306  is rotated by the small gear  308  to reduce the speed of the small gear  308  and proportionately increase the torque of the large gear  306 . The large gear  306  is affixed to a driveshaft  310  that is journaled in plates  300  and  302  such that gear  306  and drive shaft  310  rotate together. 
     Hoisting assembly  20  has a spool  312  that is affixed to drive shaft  310  and that rotates with driveshaft  310 . Upon spool  312  is wound the opposite ends of the tubing line  208 . Selectively energizing motor  248  so as to cause drive shaft  310  to rotate in a “positive” direction causes the two ends of the tubing line  208  to be unwound from spool  312 . Energizing motor  248  so as to cause driveshaft  310  to rotate in a “negative” direction causes the two ends of tubing line  208  to be wound onto the spool  312 . 
     The tubing line  208  has a midpoint that is positioned atop pulley  124  in crown  108 . From there, the opposite ends of line  314  extend down and away from the pulley  124  to traveling block  94 . The ends of line enter block  94  through openings  206  and extend under a respective one of the pulleys  214 . From pulleys  214 , the ends of line  208  extend upward to a respective one of the pulleys  122   r  and  122   l . The ends of line  208 , then, pass over pulleys  122   r  and  122   l  and down to spool  312 . It should be appreciated that when line  208  is unwound from the spool  312 , traveling block  94  is lowered in mast  14 . When line  208  is wound onto the spool  312 , the block  94  is elevated in the mast  14 . 
     The operation of workover rig  10  is by three-channel, remote control. A transmitter  250  broadcasts electrical operations signals to a receiver  252  carried within truck body  24  to activate one of a number of servos  254 ,  256  and  258  also carried within truck body  24 . Activating servos  254 ,  256  and  258  closes dual-throw switches  260 ,  262 , or  264  to selectively operate motors  148 ,  168  and  248  to move mast  14  or traveling block  94 . 
     A joystick  266  on transmitter  250  controls the operation of the pivoting assembly  16 . By moving a joystick  266  to the “up” position, an electrical operations signal is broadcast from transmitter  250  to receiver  252  carried within truck body  24 . When such a signal is received, receiver  252  produces an electrical activation signal that activates servo  254  to move dual-throw switch  260  from its normally open position to a closed position in a “positive” sense, say, toward the top of  FIG. 10 . The closed switch  260  connects motor  148  to a battery  268  carried in truck body  24  in a way that causes lever arm  154  and mast  14  to rise from its initial horizontal position shown in broken lines in  FIG. 2 . Maintaining switch  260  in the closed position described permits mast  14  to rise to a vertical orientation with truck body  24  serving as a stop to further pivoting movement. 
     Joystick  266  can be manually moved by a user to the “down” position to broadcast another electrical operations signal from transmitter  250  to receiver  252 . When this signal is received, receiver  252  produces an electrical activation signal that activates servo  254  to move switch  260  from its normally open position to a closed position in a “negative” sense, say, toward the bottom of  FIG. 10 . The closed switch  260  connects motor  148  to battery  268  in a way that provides electrical current to motor  148  in a direction that is opposite to that described in the previous paragraph so that motor  148  moves lever arm  154  and mast  14  downward toward support  38 . Support  38  serves as a stop to the continued downward pivoting of mast  14 . 
     Joystick  266  is spring-biased to a neutral position. In a neutral position, transmitter  250  broadcasts no electrical operations signal to receiver  252  and receiver  252  returns switch  260  to an open condition. So, when a user releases joystick  266 , motor  148  is deenergized to hold mast  14  at a chosen orientation: up, down, or somewhere in between. 
     When mast  14  is fully pivoted to an upright position, substantially perpendicular work floor  86  is manually pivoted away from bottom section  14   b . Then, with work floor  86  in a horizontal orientation, legs  78  are pivoted downwardly and engaged with the ground. Afterward, when play with rig  10  is complete, work floor  86  is returned to its original position against bottom section  14   b  and mast  14  is pivoted down upon support  38 . 
     Joystick  270  on transmitter  250  controls the operation of the telescoping assembly  18 . By moving a joystick  270  to the “up” position, another electrical operations signal is broadcast from transmitter  270  to receiver  252 . When this particular signal is received, receiver  252  produces an electrical activation signal that activates servo  256  to move dual-throw switch  262  from its normally open position to a closed position in a “positive” sense, toward the top of  FIG. 10 . The closed switch  262  connects motor  168  to battery  268  in a way that causes jackscrew  174  to rotate and drive top section  14   t  upwardly from bottom section  14   b . Maintaining switch  262  in the closed position, by holding joystick “up,” fully elevates top section  14   t . 
     When top section  14   t  rises from bottom section  14   b , tubing board  128  and rod basket  130  are automatically deployed from mast  14 . The upward movement of top section  14   t  puts slack in line—and permits tubing board  128  and rod basket  130  to fall away from top section  14   t . Of course, the retraction of top section  14   t  into bottom section  14   b  puts line—under sufficient tension to pivot tubing board  128  and rod basket  130  upwardly into a retracted position in top section  14   t.    
     Joystick  270  is moved by a user to the “down” position to broadcast another electrical operations signal from transmitter  250  to receiver  252 . When this signal is received, receiver  252  generates an electrical activation signal that activates servo  256  to move switch  262  from its normally open position to a closed position in a “negative” sense, i.e., toward the bottom of  FIG. 10 . The closed switch  262  connects motor  168  to battery  268  in a way that provides electrical current to motor  168  to move top section  14   t  downwardly into bottom section  14   b.    
     Joystick  270  is spring-biased to a neutral position. In a neutral position, transmitter  250  broadcasts no electrical operations signal to receiver  252 , and receiver  252  returns switch  262  to an open condition. So, when a user releases joystick  270 , motor  168  is deenergized to hold top section  14   t  at a chosen position relative to bottom section  14   b.    
     Joystick  272  on transmitter  250  controls the operation of the hoisting assembly  20 . By moving a joystick  272  to the “up” position, an electrical operations signal is broadcast from transmitter  250  to receiver  252 . When this signal is received, receiver  252  produces an electrical activation signal that activates servo  258  to move dual-throw switch  264  from its normally open position to a closed position in a “positive” sense and toward the top of  FIG. 10 . The closed switch  264  connects motor  248  to battery  268  in a way that causes spool  312  to wind up tubing line  208  thereby elevating traveling block  94 . Maintaining switch  264  in the closed position, by holding joystick  272  “up,” raises traveling block  94  into crown  108 . 
     Joystick  272  is moved by a user to the “down” position to broadcast another electrical operations signal from transmitter  250  to receiver  252 . When this signal is received, receiver  252  generates an electrical activation signal that activates servo  258  to move switch  264  from its normally open position to a closed position in a “negative” sense, i.e., toward the bottom of  FIG. 10 . The closed switch  264  connects motor  248  to battery  268  in a way that provides electrical current to motor  248  to move traveling block  94  downwardly toward work floor  86 . 
     Joystick  272  is spring-biased to a neutral position. In a neutral position, transmitter  250  broadcasts no electrical operations signal to receiver  252 , and receiver  252  returns switch  264  to an open condition. So, when a user releases joystick  272 , motor  248  is deenergized to hold traveling block  94  at a chosen position between the top and the bottom of mast  14 . 
     With traveling block  94  being positioned near work floor  86 , a user can simulate the running of tubing from a wellbore. To do this, the jaws  232  and  234  of elevator  230  are first opened, a tubing segment  22  is positioned therein, and jaws  232  and  234  are closed. Next, the elevator  230  is moved above the tubing board  128  by moving the traveling block  94  with appropriate movements of joystick  272 . Now, tubing  22  is moved laterally to a suitable space between tines  134  and, by pushing horns  238  apart, jaws  232  and  234  are reopened to release tubing  22  into the tubing board  128 . Finally, traveling block  94  is lowered back to the work floor  86  to repeat the process. The process can be repeated to provide limitless fun. 
     When play with rig  10  is complete, mast  14  can be returned to a compact state like that found on a real workover rig that is being driven over the road. Rig  10  is most easily stored in this condition. Others may prefer to keep mast  14  in an upright, substantially perpendicular and fully extended condition. In this manner, rig  10  makes a great display model and focal point wherever set up. 
     While workover rig  10  has been described above with a high degree of particularity, it will be appreciated by those skilled in making toys that modifications can be made to it. For example, wheels  26  beneath cab  28  can be made to turn via remote control to steer truck  12  and a remotely controlled motor (not shown) can be added to drive a set of wheels  26  and propel truck  12  over the ground. (Such things are, of course, commonly found in r/c cars.) Also, downwardly pivoting toolbox doors  274 , sidewalks  276  and movable ladders  278  can provide added realism. So, it is to be understood that my invention is not limited solely to workover rig  10 , but encompasses any and all workover rigs within the scope of the following claims.