Abstract:
A truck mounted crane is equipped with an earth boring bit apparatus which can be attached to the end of a crane boom to excavate holes prior to the erection of signs or other elevated pole mounted structures. The earth boring bit apparatus includes a earth boring bit attachable to a gearbox which may include an extension shaft to permit its use on the crane. The crane also includes high capacity hydraulic lines suitable for actuating the earth boring bit, which also includes a drum for collecting earth as the hole is bored so that the crane can be used to remove the debris as part of the same operation in which the hole is bored.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to the erection of outdoor signs or other elevated structures that are mounted on poles or posts. This invention also relates to truck mounted cranes in which earth boring bits can be transported on the truck and are attachable to the crane for boring holes in which the poles or posts are to be anchored. 
   2. Description of the Prior Art 
   Commercial truck mounted cranes with hydraulic booms are typically employed to erect large outdoor signs having a height of four feet or greater. These signs are commonly employed in front of commercial establishments, and their height allows potential customers to easily identify the business or its location. Since these signs are erected on site it is necessary to employ mobile trucks with cranes to erect the signs. However, conventional crane mounted trucks do not have the capability of performing all of the tasks needed to erect these signs. One critical shortcoming is that conventional truck mounted cranes cannot be employed to drill the holes in the earth or in pavement in which these signs will be erected. Normal practice requires the use of a separate vehicle, such as a line truck, that is equipped with a earth boring bit of the type suitable for drilling these holes. Since the site at which the sign is to be located may be remote from the facilities of an operator of a commercial truck mounted crane, it is often necessary to secure the services of a local contractor, with appropriate equipment, to drill the necessary holes. Quite often this can result in a significant delay for the operator of the truck mounted crane, especially when the site may be in a different state or can be quite remote from his facilities. The crane operator is then at the mercy of other contractors, with whom he may not be familiar, or who may have a significant backlog. This can result in significant delays and add significant cost. 
   U.S. Pat. No. 6,533,048 discloses an earth boring bit driven by a hydraulic motor which is connected to a boom on a mobile machine or vehicle. This earth boring bit includes a cylindrical drum in which earth or other debris from a bored hole is retained as rotating cutting teeth on the base of the drum cut into the earth or pavement. This drum serves to collect the debris, which can then be removed from the hole to a neighboring collection point or container. When the bit has been moved to the collection location by rotation of the boom on which it is mounted, the base of the drum can be allowed to swing open, emptying the debris removed from the hole. This earth boring bit can be used instead of augers or other boring bits, which require a separate implement to remove earth or other debris from the bored hole. This earth boring bit can be used on a vehicle with a swinging hydraulic boom or on tractors, skid steer backhoes or other mobile machines or vehicles having a stationary boom. This earth boring bit is intended for use on line trucks or other equipment that is normally used at least in part for earth moving operations, such as drilling holes, and includes a hydraulic system having sufficient capacity for operating the earth boring bit. In particular, this earth boring bit is intended for use with vehicles having a boom capable of delivering sufficient hydraulic fluid to the hydraulic motor suspended from the end of the boom above this earth boring bit. 
   SUMMARY OF THE INVENTION 
   According to this invention, a method of erecting a post structure, such as an outdoor sign, which can have a height in excess of ten feet, uses a single crane apparatus including a hydraulic system for conventional use on the crane, which is connected to a source of hydraulic fluid. The method includes the following steps. An earth boring bit is connected to the source of hydraulic fluid through hydraulic lines extending from the base to the end of the single crane apparatus. The earth boring bit is hydraulically actuated through the hydraulic line to excavate a hole for erection of the post structure. Earth is removed from the hole by employing the crane to lift the earth boring bit from the hole. The earth boring bit is disconnected from the hydraulic line, which is disconnectable from the source of hydraulic fluid adjacent the base of the crane so that the hydraulic pressure is available for other functions of the crane. The post structure is erected in the evacuated hole with the crane, so that only a single crane needs to be employed to both evacuate a hole receiving the post structure and to erect the post structure anchored in the evacuated hole. 
   A method of erecting an outdoor sign at a site distant from an operator&#39;s premises using only a single truck equipped with a crane apparatus can also include the following steps. An earth boring bit apparatus is transported on the truck to the site at which the outdoor sign is to be erected. At the site, the earth boring bit apparatus is removed from the truck using the crane. The earth boring bit apparatus is connected to hydraulic lines on the crane. The earth boring bit apparatus is positioned using the crane apparatus to excavate a hole in which the sign is to be placed. The hole is excavated using the earth boring bit apparatus and employing the crane to transport debris from the hole. The earth boring bit apparatus is then disconnected from the crane apparatus and the hydraulic lines after the hole has been excavated. The outdoor sign is erected by positioning the steel or other support structure, on which the outdoor sign is to be mounted, in the excavated hole using the same crane apparatus employed with the earth boring bit. Separate mobile equipment, other than the truck equipped with the crane apparatus and the earth boring bit apparatus, is not needed at the site. 
   A truck suitable for erecting a sign or other elevated structure according to these methods can include the following components: A crane mounted on the truck includes a hydraulic system with hydraulic lines extending from adjacent the base to the top or remote end of the crane. An earth boring bit is transportable on the truck separate from the crane. A gearbox apparatus, including an extension segment, is also transportable on the truck separate from the crane and the earth boring bit apparatus. The gearbox can be attached between the hydraulic system and to the earth boring bit, so that the earth boring bit may be rotated to excavate a hole in which the outdoor signs are to be erected. The crane can be used to assemble the gearbox to the earth boring bit apparatus. 
   This method and apparatus reduces the need for the operator of the truck to obtain assistance of others, such as operators of line trucks equipped to excavate holes, as he assembles signs at remote jobsites. The earth boring bit can be driven by the hydraulic system on the truck mounted crane when the earth boring bit is mounted on the crane. The crane and the earth boring bit can also be used to remove the earth or other debris created as holes are bored, eliminating the need to manually remover the earth or debris or to use separate equipment for earth removal. The operator of a truck mounted crane equipped in this manner is therefore less dependent on others and can avoid costly delays in completing his task, especially at remote locations with which the operator may be unfamiliar. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a view of a truck mounted crane apparatus, or sign truck, equipped to erect an outdoor sign or other elevated structure, and to excavate holes in which the sign will be positioned. The crane is shown partially lifting a pole or structural support for mounting a sign. 
       FIG. 2  is a view of an earth boring bit and gear box mounted on one end of a crane or boom, mounted on the truck shown in  FIG. 1 , in position to excavate a hole for erecting a sign. 
       FIGS. 3A and 3B  are views of a prior art earth boring bit used with the crane as shown in  FIG. 2 .  FIG. 3A  shows the bit in the closed position and  FIG. 3B  shows the bit in the open or dumping position. 
       FIG. 4  is a view of the gear box, with an extension segment, employed with the earth boring bit in the manner shown in  FIG. 2 . 
       FIG. 5  is a view of a view of a mounting bracket on the crane boom for mounting the gearbox to the boom. 
       FIG. 6  is a view of the connection of high capacity hydraulic lines mounted on the crane boom for driving the earth boring bit. 
       FIG. 7  is a view of the stand used to position the earth boring bit on the truck shown in  FIG. 1  and for positioning the earth boring bit in position for connecting the gear box and earth boring bit to the crane. 
       FIG. 8  shows and outdoor sign of the type that can be erected by the single vehicle described herein. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  shows an aerial ladder crane comprising a unit providing crane capability and aerial ladder capability in one integral unit, which may be used for hoisting loads and for access or as a working platform, and is commonly referred to as a sign crane truck  2 . This mobile apparatus can be used for erecting outdoor signs  2  on poles  4  or other elevated structures including posts or poles anchored in hole. In addition to providing means for hoisting and erecting these elevated structures, the sign truck  2  also includes means for excavating holes  6  in earth, pavement or other substructures. 
   The truck  2  includes a crane apparatus  20 , which is permanently mounted on the bed of the truck  2 , and an earth boring bit apparatus  40  that is carried and transported on the truck  2  and can be attached to the crane apparatus  20  at an on site location. The earth boring bit apparatus  20  includes an earth boring bit  42  and a gearbox  60  which can be attached on site to a hydraulic system, which is part of the truck  2 . 
   The preferred embodiment of the earth boring bit  42  is described in further detail in U.S. Pat. No. 6,533,048, which is incorporated herein by reference. This earth boring bit  42  includes a cylindrical drum  44 , which includes a pivoting base  46 . Cutting teeth  48  on the base  48  dig into the earth as the earth boring bit  42  is rotated about the axis of revolution of the cylindrical drum  44 . The earth or debris or other residue created by the rotating bit teeth  48  is deposited in the cylindrical drum  44  while in the closed position. After a hole has been excavated to a desired depth, or to the depth at which this earth boring bit  42  can reach, the bit  42 , with the drum base  46  in the closed position, is removed from the excavated hole. This earth boring bit  42  can then be moved to another position spaced from the hole and the drum base  46  can be released in the manner described in U.S. Pat. No. 6,533,048 to deposit the earth or other excavated debris at a location remote from the hole or in a separate container which can be hauled away from the job site. 
   The crane  20  mounted on sign truck  10  is hydraulically operable by a hydraulic system that is part of the sign truck. This crane  20  is rotatable about its base and segments of the crane boom  22  are telescoped permitting the crane  20  to reach heights sufficient to erect most conventional outdoor signs having a height of ten feet or more. Crane  20  includes a basket or working platform  28  located on the end of the distal boom section. A pair of hydraulic lines  30 , attached to one side of the outer crane boom, has sufficient capacity to power this earth boring bit apparatus. In the preferred embodiment of this invention, hydraulic lines  30  are operable at a pressure of 2300 psi. with a flow rate of 22 gal/min. Standard hydraulic connectors are located at opposite ends of second hydraulic line  30 . The hydraulic lines  30  can therefore be attached near the base of the crane  20  to the same hydraulic connectors that normally hydraulic lines for manipulating the hoist or load line or cable which is mounted on the crane and is attached to a load adjacent the end of the crane. In the preferred embodiment of this invention, the hydraulic lines that are used to manipulate the hoist or load line or cable are disconnected when the second hydraulic lines are connected because operation of the earth boring bit is not dependent upon this line or cable. The hydraulic connectors on the other end of the hydraulic lines  30  will permit attachment and detachment of the earth boring bit apparatus  40  to the source of hydraulic pressure to power the earth boring bit apparatus  40 . 
   The earth boring bit apparatus  40  comprising the earth boring bit  42 , the gearbox  60  and an extension shaft or segment  62  can be attached to the crane  20  at the site where a sign or other elevated structure is to be erected. The earth boring bit  42 , the gearbox  60  and the extension segment  62  can be transported on the crane truck  10  in their disassembled configuration. In the preferred embodiment of this invention, a standard Model X2475 gearbox, manufactured by McMillen is employed. In the preferred embodiment of this invention, the gearbox  60  with the extension segment attached has a combined height of approximately thirteen feet. The preferred embodiment of this invention is capable of excavating a hole to a depth of up to eleven feet. To assemble the various components at the job site, the crane is first used to remove the earth boring bit  42  from its stored position on the truck. A load line extending from the end of the crane is attached to the bit shaft  45  and the bit  42  and its stand are lowered from the truck and placed on the ground adjacent to the truck. In order to avoid complications in assembling the earth boring bit apparatus  40 , the bit  42 , in its stand  52  should be placed on a level surface. The extension shaft  62  is attached to the gearbox  60 , and this assembly is then raised by the crane after attaching the load line to the gearbox assembly. The gearbox assembly is then moved into position over the earth boring bit  42  and the extension segment  62  is then mated to the shaft  45  on the earth boring bit  42 . A mounting bracket  32 , attached to the end of the crane  20 , as shown in  FIG. 5 , comprising the means for physically attaching the earth boring apparatus  40  to the crane  20 . A gearbox coupling  64 , located at the top of the gearbox  60  is aligned with the mounting bracket  32 , and a pin (not shown) is used to physically attach the earth boring bit apparatus  40  to the crane  20 . Standard hydraulic connectors  66  attached to the gearbox  60  are mated with hydraulic connectors on the hydraulic lines  30  adjacent the remote or upper end of the crane or boom  20 . The hydraulic lines  30  are also attached to the hydraulic system at the opposite end of the hydraulic lines  30  at the base of the crane  20 . In the preferred embodiment hydraulic lines, which are normally used to manipulate the hoist or load line are disconnected in order to connect the lines  30  extending to the top of the crane. The earth boring bit apparatus  20  is now connected to the sign truck&#39;s hydraulic system, since the hoist or load line is not needed to operate the earth boring bit. The earth boring bit apparatus  20  is then moved to the exact location at which a hole is to be excavated. The hydraulic system causes the earth boring bit  42  to rotate, excavating a hole to a desired depth. Since the earth or debris removed in boring the hole is collected in the closed drum  44 , it can be removed from the excavated hole by the crane  20  and placed at a collection point or collection receptacle. 
   After the hole has been excavated, the earth boring bit apparatus  40  can be dissembled and returned to its storage and transportation position on the sign truck  10 . It should be noted that more than one earth boring bit  42  can be stored and transported on the same truck. The earth boring bit  42  is stored and transported in a stand  50 , which is removable from the truck  10  along with the bit  42 . Stand  50  comprises means for holding the bit  42  in an upright position, both during storage and transportation and when the bit  42  is placed on a level surface for assembly to the gearbox  60 , and gearbox extension segment  62  to prepare to bore a hole. Stand  60  includes a base  52 , which in the preferred embodiment of the invention comprises a cross configuration formed of metal beams having a sufficient strength to support the bit  42 . Arms  54  extend upward from each of the beams forming the stand base  52 . These arms  54  are spaced apart so that the earth boring bit  42  can be placed between the four arms  54 , and the arms will hold the bit  42  in an upright position. A central projection  56  extends upward form the middle of the base  52 , where the beams cross. This central projection  56  extend upward to support the bit base  46  so that the cutting teeth  48  and other components extending beyond the bit base  46  are not damaged during storage or transportation. Earth boring bits  42  are available in different sized having different outer diameters for boring different size holes. Since the sign truck  10  is intended for use at remote locations, it is often desirable to have bits  42  of different sizes available for different jobs. 
   Once the earth boring bit apparatus  40  has been disconnected from the end of the crane  20 , the crane  20  can be used in a conventional manner to erect a sign or some other elevated structure. The primary hydraulic lines  26  are reconnected to the hydraulic system, after disconnection of the second or auxiliary lines  30 . A load line extending from the end of the crane  20  can be attached to a pole or post  4  that will support the sign  2  at a raised position. A lower end of the pole or post  4  is then placed in the previously excavated hole  6 , and held in this position as concrete or a quick setting mixture such as Sakrete, is poured into the excavated hole surrounding the pole. Sakrete is a registered trademark of Sakrete Inc. After the concrete or other mixture has hardened to an extent necessary to support the pole  6 , other necessary poles can be erected in a similar manner or other portions of the sign can be erected with the use of the crane. Assuming the body of the sign has not been previously attached to the pole or poles  6 , this sign body will be raised into position by the crane in a conventional manner and attached to the poles by welding, bolting or some other attachment means. The basket, bucket, or working platform  28  on the end of the crane  20  supports a worker as other operations, such as the installation and connection of electrically wiring and components are completed. The earth boring bit apparatus  40  can be transported on the truck and mounted to the crane  20  without interfering with these other conventional structures that are mounted on the crane. However with the exception of pouring the concrete and other minor tasks which may not necessitate the use of a vehicle, the complete erection of a sign  2  can be accomplished by use of the sign truck  2 , and not other vehicles, such as tractors for the excavation of holes and the removal of debris are necessary. It should be understood that while the earth boring bit  42  is the preferred bit for excavation holes according to this invention, other earth boring bits, such as augers, can be employed, even if their use may not be as efficient. It should also be understood that other crane mounted truck configurations can also be employed. For instance, the crane could be mounted on the front of the truck bed, adjacent the cab, instead of at the rear of the truck. Although the bucket or basket mounted on the end of the crane is a desirable component, its inclusion is not essential. Therefore, this invention is defined by the following claims and is not limited to the representative embodiment depicted herein.