Ground anchor
BACKGROUND OF THE INVENTION 
     This invention relates to anchor equipment and more particularly to novel and improved anchor equipment which is adapted to be disposed within an open trench to anchor a cable thereto which is used to pull construction equipment along the trench. 
     An example of the type construction equipment is, for example, equipment used to construct concrete pipe which is cast in place in a manner well known to those skilled in the art. For example, a cast-in-place concrete pipe section is constructed in a manner whereby a machine is placed directly into the trench and concrete is fed into the machine where it is tamped and vibrated and poured into the trench forming the pipe as the machine actually moves along the trench. This type of machine is well known to those skilled in the art and no attempt shall be made to explain its operation and function in this application. 
     Heretofore, in order to move the machine along the trench, a piece of heavy equipment was attached to the machine and would pull it along at a regulated speed. 
     Another method heretofore used is to provide a winch on the machine and couple a cable onto the winch and the other end thereof to a piece of equipment spaced a distance along the trench. Such anchoring equipment, heretofore used, was a backhoe, for example. 
     The present invention overcomes all the disadvantages of the prior art in that it provides a novel and improved earth engaging anchor of the present invention which is placed directly into the trench. A cable from the winch on the equipment desired to be moved is coupled to the earth engaging anchor. As pressure is placed on the anchor, the earth engaging blades on the anchor becomes more deeply entrenched into the sidewalls of the trench and becomes more firmly secured to the sidewalls and bottom of the trench as pressure is applied. 
     SUMMARY OF THE INVENTION 
     Briefly described, the present invention comprises an anchor for use in an open trench. The anchor includes a first elongated concave sleeve section which has a longitudinal axis and is adapted to be disposed horizontally in one side of the open trench. A second elongated concave sleeve section which has a similar longitudinal axis is also disposed horizontally in the open trench and adjacent the first sleeve portion. Each sleeve portion is then hinged together along the bottom of the trench at the outer edges thereof. Each section then forms a semicircular concave cylinder. At the top of each sleeve section and positioned longitudinally therewith are a pair of spaced parallel ribs forming a channel therebetween. A plurality of earth engaging blades are mounted on the outer sides of each of the sleeves and are adapted to engage the earth on each side of the open trench. The blades may be angled in a helical curve to engage the earth, the blades on one sleeve are angled opposed to the blade on the other sleeve. Means are included within the inside of each sleeve to force the sleeves away from each other, pivoting on the hinged area, causing the earth engaging blades to engage the sidewalls of the open trench, and at the same time causing the spaced top ribs to engage the trench to prevent the anchor from rising. This latter mentioned earth engaging means includes a first arm which is pivotally mounted to the inner side of the first sleeve near the bottom rib of the spaced parallel ribs and a second arm which is pivotally mounted to the inner side of the second sleeve near the bottom rib of the spaced parallel ribs. The free ends of the arms are then pivotally mounted together. An eye is coupled to the arms at the pivot point and a pulley is mounted on the inner side of the sleeves. A cable is coupled to the eye and is placed through the pulley. By applying pressure to the cable the arms are pulled downwardly causing the sleeves to be forced away from each other. The blades then become entrenched into the sides of the trench. 
     A winch placed upon a piece of earth working machine then draws upon the cable causing the anchor to open and dig into the trench. The cable is then used to move the machine towards the anchor. The more pressure applied to the cable the tighter the anchor will hold. 
     This eliminates the need for the use of equipment to either hold the cable in place or machinery to impart movement of the machine. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     These and other advantages will become more apparent to those skilled in the art when taken into consideration with the following detailed description wherein like reference numerals indicate like and corresponding parts throughout the several views and wherein: 
     FIG. 1 is a top plan view of the anchor construction of the present invention illustrating the position of the trench and having a winch attached thereto; 
     FIG. 2 is a section view taken along the line of 2--2 of FIG. 1 showing the anchor in the trench; 
     FIG. 3 is a view of the anchor removed from the trench; 
     FIG. 4 is a side view of the anchor of FIG. 3 shown outside the trench; and 
     FIG. 5 is a partial section view taken along lines 5--5 of FIG. 4 showing a preferred view of the blades. 
    
    
     DESCRIPTION OF ONE PREFERRED EMBODIMENT 
     In the present invention there is shown generally in FIGS. 1 and 2 the anchor 10 of the present invention as it is placed within a trench 12, for the purpose of the description the trench is normally a concave shaped ditch dug into the earth for the purpose of laying pipe or other similar type of construction work. 
     The anchor 10 and the preferable construction equipment 16 is positioned within the walls of the trench 14. The construction equipment 16 has a winch 18 mounted thereon which is used to urge the construction equipment toward the anchor 10 in a manner yet to be described. 
     The anchor 10 comprises a first sleeve section 20 and a second sleeve section 22. Each of these sleeve sections 20 and 22 are coupled together by the hinge 24 best shown in FIG. 3. The first sleeve section 20 and the second sleeve section 22 are symmetrical in design and formed a sectional sleeve having a concave inner portion and a convex outer portion. 
     In the preferred embodiment shown there are three blades, 28, 30 and 32, which are fixed to the outer periphery of the sleeves of the first and second sleeve section. The blades are broken at the hinge area and coupled thereto in a suitable manner, these blades 28, 30 and 32 protrude outwardly from the outer walls of each of the sleeve sections 20 and 22. 
     A pair of spaced ribs 29 and 31 are positioned along the tops of sleeve section 20 and parallel to each other forming a channel therebetween. A second pair of spaced ribs 33 and 35 are positioned along the top of sleeve section 22 and parallel to each other and also forming a channel therebetween. These ribs 29, 31 and 33, 35 are used to maintain the anchor 10 from rising from the trench when pressure is placed thereon as hereinafter to be explained. 
     As is shown in the described embodiment the blades 36 are angled on each sleeve in an opposing position to form opposing helical angles. This angle on the blade adds an advantage in that the angle being in the direction of pull causes the blades to become deeper entrenched into the sidewalls 14 of the trench 12 as pressure is placed in the pulling direction as hereinafter to be explained. 
     A pair of mounting brackets 38 and 40 extend inwardly from the inner periphery of each sleeve, near the bottom ribs 29 and 33 respectively. Each bracket, 38 and 40 is mounted to an opposite sleeve 20 and 22, respectively. 
     A pair of arms, 42 and 44, are pivotally coupled to the brackets 38 and 40, respectively, in a suitable manner by the pivot pins 46 and 48. Each arm extends inwardly and upwardly at an angle from the innermost perimeter of the sleeves sections 20 and 22 and are coupled together at point 50 by a pivot pin 52. The pivot pin 52 may have an eye 54. A cable 60 is connected to the eye 54. 
     A mounting bracket 62 is coupled to the bottom of sleeve section 20 on the inner periphery thereof and has a pulley 64 mounted by a suitable pin 66, the cable 60 coupled to the eye 54 extends through the pulley 64 and is stretched the distance of the trench 12 to the winch 18 of the construction equipment 16. 
     In operation of the shown embodiment of this invention, it may be desired that certain construction equipment 16 as shown in FIG. 1 be drawn through an open trench 12 toward a certain point to where the anchor 10 is positioned. In order to do this, a winch 18 is coupled to the equipment 16 and turned by a suitable means such as a motor or engine or the like, (not shown). 
     The anchor of the present invention is coupled directly to the winch 18 by the cable 60. As the cable is drawn tight, it pulls the pivot point 20 of the two arms 42 and 44 downwardly toward the pulley 64, causing the first sleeve section and second section to be forced outwardly from each other. Not only does this cause the blades 28, 30 and 32 to become deeply imbedded into the trench walls 14 of the trench 12, anchoring the sleeves firmly in place, but also it causes the ribs 29, 31 and 33, 35 to become imbedded in the side walls 14 of the trench preventing the anchor 10 from rising in the trench. The tighter the winch 18 pulls on the cable 60, the deeper the blades 28, 30 and 32 dig into the side walls 14 of the trench 12, thus causing the anchor to be anchored into position and allowing the earth moving equipment to be drawn toward the anchor 10. Because of the helical shape of the blades 36, the more pressure applied to cable, the deeper the blades become wedged into the earth. 
     The present invention will also work well in a square shaped trench because the curved shape blades 36 cause the blades to be imbedded in three parts, top and sides.