Patent Publication Number: US-7594679-B1

Title: Outrigger for a boom truck or the like

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. Provisional Application Ser. No. 60/844,219 entitled “OUTRIGGER FOR A BOOM TRUCK OR THE LIKE” filed Sep. 13, 2006, the disclosure of which is hereby incorporated herein by reference. This is a continuation-in-part application of application Ser. No. 11/521,332 filed Sep. 14, 2006, entitled “DUAL MODE OUTRIGGER FOR A BOOM TRUCK OR THE LIKE” which is a divisional application of application Ser. No. 11/038,338 filed Jan. 19, 2005, entitled “DUAL MODE OUTRIGGER FOR A BOOM TRUCK OR THE LIKE” (now U.S. Pat. No. 7,150,472). 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to an outrigger for a boom truck or the like and more particularly to an outrigger for a boom truck or the like which may be extended outwardly, forwardly and downwardly from one side of a boom truck or the like. 
   2. Description of the Related Art 
   In applicant&#39;s U.S. Pat. No. 7,150,472 entitled “DUAL MODE OUTRIGGER FOR A BOOM TRUCK OR THE LIKE”, the disclosure of which is incorporated herein by reference thereto, a pair of outriggers of the A-frame type are disclosed, each of which may be extended outwardly and downwardly from one side of the truck or which may be extended downwardly at one side of the truck. Although the dual mode outrigger of U.S. Pat. No. 7,150,472 is meeting with success, the applicant herein is desirous of providing an A-frame outrigger of either the single or dual mode which may be extended outwardly, forwardly and downwardly from the side of the truck to eliminate the need for an outrigger at the front end of the truck. One might think that the same would be easily accomplished by simply pivotally connecting the inner end of the outrigger, about a vertical axis, to the truck. If the outrigger is simply pivoted to the truck, the outer end of the outrigger, in its deployed or extended position, will not be located sufficiently laterally distant from the side of the truck thereby reducing the stability of the truck. The next logical thing that a designer may do to solve the problem is to simply lengthen the outrigger to place the outer end thereof sufficiently distant from the truck to achieve the necessary stability for the truck. However, simply lengthening the outrigger is not possible due to the necessity of having adequate space adjacent the truck to store the outrigger in its inoperative or stored position. 
   SUMMARY OF THE INVENTION 
   An A-frame outrigger for a boom truck or the like is disclosed which normally will be mounted at each side of the truck. The inner end of the outrigger is pivotally secured, about a vertical axis and a horizontal axis, to the boom truck so that the outrigger, when extended, may be extended outwardly, downwardly and forwardly with respect thereto. The outrigger includes an inner tubular section, an intermediate tubular section which slidably embraces the inner tubular section, and an outer tubular section which slidably embraces the intermediate section. A pivotal ground engaging shoe is provided at the outer end of the outer tubular section. 
   A two-stage hydraulic cylinder is positioned within the tubular sections and has its base end connected to the inner end of the inner tubular section. The rod end of the hydraulic cylinder is connected to the outer end of the outer tubular section. A pair of cables are secured to the outer end of the rod end or the outer end of the outer tubular section. The cables extend inwardly through the interiors of the outer tubular section and the intermediate tubular section and extend around a pair of pulleys or sheaves which are rotatably secured to the inner interior end of the intermediate tubular section with the ends of the cables being secured to the outer end of the inner tubular section. The cables may be replaced with a hydraulic proportioning system. 
   Upon extension of the hydraulic cylinder, the intermediate and outer tubular sections are extended simultaneously due to the action of the two-stage hydraulic cylinder and the cable connections. Upon retraction of the hydraulic cylinder, the intermediate and outer tubular sections are retracted simultaneously. The extended outrigger may have its outer end positioned outwardly, downwardly and forwardly with respect to its inner end so that there is no need for an outrigger at the forward end of the truck. 
   It is therefore a principal object of the invention to provide an outrigger for a boom truck or the like. 
   A further object of the invention is to provide an improved outrigger for a boom truck or the like which may be extended outwardly, forwardly and downwardly from one side of a boom truck or the like. 
   A further object of the invention is to provide an outrigger for a boom truck wherein the outrigger utilizes three tubular sections and a two-stage hydraulic cylinder for extending and retracting the tubular members. 
   Yet another object of the invention is to provide an outrigger for a boom truck or the like which eliminates the need for a front jack or outrigger secured to the front end of the truck. 
   These and other objects will be apparent to those skilled in the art. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a top view of the outrigger of this invention extending outwardly, forwardly and downwardly from the right side of the boom truck or the like; 
       FIG. 2  is a front perspective view of the embodiment of  FIG. 1 ; 
       FIG. 3  is a rear elevational view illustrating one outrigger of this invention extending laterally from the right side of the boom truck or the like, and a second outrigger at the other side of the boom truck in a retracted position; 
       FIG. 4  is an exploded perspective view of the outrigger; 
       FIG. 5  is a sectional view of the outrigger in an extended position; 
       FIG. 6  is a sectional view of the outrigger in an extended position transversely to  FIG. 5 ; and 
       FIG. 7  is a sectional view of the outrigger in a retracted position. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   In the drawings, the numeral  10  refers to a boom truck or the like such as the truck disclosed in U.S. Pat. No. 7,150,472 entitled “DUAL MODE OUTRIGGER FOR A BOOM TRUCK OR THE LIKE”. Although the outrigger of this invention is ideally suited for use as a dual mode outrigger, the outrigger of this invention may be used as a single mode outrigger if so desired. 
   For purposes of description, the boom truck  10  will be described as having a forward end  12 , a rearward end  14 , and opposite sides  16  and  18 . A frame  20  extends rearwardly from the cab  22  in conventional fashion. 
   The outrigger of this invention is generally referred to by the reference numeral  24  and has an inner end  26  and an outer end  28 . The inner end  26  of outrigger  24  is pivotally secured to either side of the frame  20  about a vertical axis in a conventional fashion and by a horizontal axis referred to by the reference numeral  30 . In some situations such as illustrated in  FIG. 3 , the inner end of the boom  24  may be secured to a pedestal, turret or support  32  about a horizontal axis with the turret or support  32  being rotatable about a vertical axis. A conventional hydraulic cylinder (not shown) extends between the outrigger and the truck frame or the like for raising and lowering the outrigger  24  about a horizontal axis. 
   The outrigger  24  includes an inner section or tubular section  34  which is pivotally secured to the truck either about a horizontal axis and/or a vertical axis. Outrigger  24  also includes an intermediate outrigger section  40  which slidably embraces outrigger section  38  and which has an upper end  42  and a lower end  44 . Outrigger  24  also includes an outer tubular section  46  which slidably embraces outrigger section  40 . 
   A two-stage hydraulic cylinder  48  has its base end secured to a trunion or the pivot point  36  and includes cylinder portions or rod portions  50  and  52 . Cylinder  48  is a double acting cylinder in that it may be extended and retracted by hydraulic pressure with the truck  10  providing the suitable hydraulic pressure. The outer end of rod  52  is connected to a trunion  54  or the like which is secured to the outer end of outrigger section  46 . A pair of cables  56  and  58  are connected to the trunion or the like  54  and extend inwardly therefrom and pass around a pair of pulleys or spools  60  and  62  which are rotatably secured to the inside surface of outrigger section  40 . The ends of cables  56  and  58  are secured to the outer end of outrigger section  38  at  64  and  66 , respectively. Although cables are shown, the cables could be replaced by a conventional hydraulic proportioning system. The reason for utilizing the cables  56  and  58  or a hydraulic proportioning system of conventional design is to ensure that the rod portions  50  and  52  cause the tubular sections  40  and  46  to extend in unison. If the cables  56  and  58  or a hydraulic proportioning system is not used, the outer tubular section  46  will normally extend first which will drive the foot  68  into ground engagement before any pivoting of the outrigger is possible. The numeral  59  refers to a cable system illustrated in  FIGS. 5-7  which ensures that the tubular sections  40  and  46  will be retracted in unison. The ground engaging foot  68  is pivotally secured to the outer end of outrigger section  46  in conventional fashion. A pair of elongated links  70  and  72  pivotally connect the inner end of tubular section  40  to a bracket assembly  74  fixed to the vehicle. 
   In operation, if the outrigger  24  is to extend outwardly, forwardly and downwardly from the truck, as illustrated in  FIGS. 1 and 2 , the retracted outrigger  24  is swung to that desired position about the vertical axis. Hydraulic cylinder  48  is then extended, which causes the rod portions  50  and  52  to extend therefrom in unison which causes outrigger section  46  and outrigger section  40  to be moved outwardly in unison with respect to the outrigger section due to the pivotal connection of the outrigger to a fixed support by the elongated links  70  and  72 . As outrigger section  46  moves outwardly, the cables  56  and  58 , by passing over the pulleys  60  and  62 , cause the outrigger section  40  to be pulled outwardly in unison with the outrigger section  46  which causes the outrigger to pivotally move with respect to the vehicle so as to swing outwardly from the vehicle thereby preventing the foot  68  from coming into ground engagement until the desired position of the outrigger is reached. Additional cables will ordinarily be used to cause the outrigger section  40  to be pulled inwardly in unison with the outrigger  46 . The conventional hydraulic cylinder which extends between the inner tubular section  34  and the truck frame or boom frame enables the outer end of the outrigger to be raised and lowered. Thus, the three-section outrigger enables the outer end of the outrigger to be spaced sufficiently laterally of the vehicle and forwardly with respect to the vehicle so that a front outrigger is not required, as illustrated in  FIGS. 1 and 2 . By utilizing the three-section outrigger, the outrigger in its stowed position will not occupy an objectionable amount of space, as seen on the left side of  FIG. 3 . 
   Thus it can be seen that the invention accomplishes at least all of its stated objectives.