Abstract:
A lift-fork type carriage means capable of lifting, carrying and emplacing filled gabion baskets into position in a revetment mattress lining a stream bed or other erosion prone area to control water erosion. The gabion basket handling device is characterized by a plurality of lift-fork tines adapted to engage the under-surface of a filled gabion basket, a plurality of hold-down arms rotatable into contact with the top and one side of the filled gabion basket by linkage means actuated upon application of lifting forces to the apparatus. The hold-down arm linkage is counterbalanced so that lifting forces applied to the apparatus when empty are insufficient to rotate the hold-down arms into a closed position.

Description:
BACKGROUND OF THE INVENTION 
     This invention is directed to an apparatus and method for emplacing filled gabion baskets in a revetment mattress. Heretofore emplacement of gabion baskets was accomplished by moving the empty wire-framed gabion basket into its position adjacent other previously emplaced gabion baskets, wiring the basket to the adjacent baskets, filling the basket by placing rocks of various sizes therein and closing the basket so as to form a secure layer of rocks bounded by wire mesh at a location in a stream, canal, or the like where erosion from water flow is anticipated. The transportation of the rocks necessary and the difficulty of getting the rocks from a road bed upon which a vehicle can travel to the gabion baskets in a stream bed made the emplacement of gabion baskets by the prior art method an extremely laborious and time consuming process as well as involving substantial expense for the handwork and labor necessary to place the baskets. 
     Prior art devices for utility carriage of various objects suffer from the inability to angle the bottom of the device as is necessary to emplace a filled gabion basket in a stream bed or the like or have been found to be unduly complicated in their mechanical structure in requiring a plurality of hydraulic or other operating mechanisms and the like to accomplish the necessary lifting, grasping, and holding of the gabion baskets. For example, U.S. Pat. No. 3,817,567 shows a utility carriage for mobile loaders having a plurality of hydraulic cylinders as the actuating means for the hold-down fingers shown therein. No provision is made for usage of this device with a single lifting cable such as a crane or a line attached to a backhoe. As a consequence of the hydraulic actuating mechanism, single line operation is not possible. In U.S. Pat. No. 3,863,971 an adjustable support for a material handling fork is shown in order to balance the fork when handling various loads. Again, control mechanisms and complex equipment is necessary to accomplish the goals of the apparatus set forth therein. 
     SUMMARY OF THE INVENTION 
     The present invention is an apparatus for emplacing filled gabion baskets in a revetment mattress and further a method of forming a revetment mattress using filled gabion baskets. The apparatus comprises a lift-fork type device operable from a single lift cable. A frame carries a set of rigidly attached fork tines adapted to slide underneath a filled gabion basket on a specially constructed pallet and one or more sets of rotatively mounted hold-down arms actuated by lifting forces imposed upon the apparatus. The hold-down arms rotate into engagement with a filled gabion basket to prevent the gabion basket from sliding off the fork tines when held at an attitude approximating the slope of the stream bed into which the gabion basket is to be placed. The hold-down arms are counterbalanced against rotation in the absence of the weight provided by the filled gabion baskets so that the apparatus may be transported with the hold-down arms in the open position whenever the apparatus is empty. The apparatus is equipped with two lift points, the first being the main lift for carrying and transporting the apparatus in either the filled gabion basket carrying mode or empty and the secondary lift means adapted to remove the apparatus from engagement with the gabion basket whenever the filled gabion basket has been emplaced in its operative location in the stream bed. Lift on the secondary lift means causes the fork tines to be withdrawn from underneath the emplaced gabion basket. 
     The method of this invention comprises filling gabion baskets upon a flat surface having specially constructed pallets thereon or otherwise equipped to permit insertion of the arms of a gabion basket lift apparatus directly underneath the lower surface of the gabion basket. The filled gabion baskets, containing rocks or other objects are wired shut and transported to a position adjacent the stream bed in which a revetment mattress is to be formed from gabion baskets. The gabion basket lift apparatus described herein is inserted beneath the gabion basket, the hold-down arms are rotated into engagement with the top and outer edge of the gabion basket and the entire apparatus lifted by use of a single lift line. Upon placing tension on the lift line the apparatus assumes an attitude approximating the slope of the stream bed in which the revetment mattress is being placed. The gabion basket lift apparatus containing the filled gabion basket is then moved into position such as by rotation of the crane apparatus or other lift equipment utilized and transported to the position at which the basket is desired. The equipment is lowered until the main lift line is slack, and the hold-down arms are rotated out of contact with the gabion basket. The secondary lift means is then utilized to withdraw the gabion basket lift device from engagement with the gabion basket. The basket is then wired to adjacent gabion baskets to form the revetment mattress and the process repeated until the necessary number of gabion baskets are emplaced. 
     OBJECTS OF THE INVENTION 
     It is one object of this invention to provide apparatus for lifting, transporting, and emplacing filled gabion baskets in a revetment mattress. 
     It is a second object of this invention to provide a method of forming revetment mattresses from gabion baskets wherein the baskets are filled prior to emplacement thereof in the stream bed. 
     It is a further object of this invention to provide gabion basket emplacement apparatus which may operate on a single lift line such as by a crane or by attachment of a single line to the bucket of a backhoe and which transports the filled gabion baskets from their rest position on a truck or other transport means to the revetment mattress area inclined at an angle approximating the slope of the stream bed in which the revetment mattress is being formed. 
     These and other objects and advantages of this invention will become readily apparent to one of skill in this art upon a detailed examination of the appended drawings and study of the description thereof which follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a rear prospective view of the apparatus of this invention. 
     FIG. 2 is a side elevational view of the apparatus shown in FIG. 1. 
     FIG. 3 is a side elevational view of the apparatus shown in FIG. 1 wherein a filled gabion basket is disposed upon the forks of the apparatus and is shown positioned adjacent the intended location for the basket in a revetment mattress. 
     FIG. 4 is a side elevational view of the apparatus shown in FIG. 1 wherein the secondary lift means is being utilized to remove the apparatus from contact with the filled gabion basket. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring specifically to the drawings wherein like numerals indicate like parts, there is seen in FIG. 1 a gabion basket lift apparatus in which a plurality of fork lift tines 11a through 11d are shown attached to the bottom terminal portions of vertical frame elements 10a through 10d. The frame elements are also connected together by crossbeam 16 at the lower end thereof and extend upwardly to a second crossmember 18 which comprises a boxbeam extending across the full length of the apparatus. Each vertical frame member 10a through 10d is securely welded to boxbeam 18 and to crossmember 16 to form a rigid lifting apparatus. Fork tines 11a through 11d are chosen in length to accomodate the width of a gabion basket. The gabion basket such as that shown in FIG. 2 comprises a wire mesh basket which is filled with stones of varying diameters in the range of a minimum of about 2 inches to a maximum of 12 to 15 inches with the normal run being 6 to 10 inches in diameter. 
     Hold-down arms 14a through 14d are adapted to rotate into contact with the upper surface and one edge of the gabion basket. The terminal end of arm 14 is bent downwardly to prevent the gabion basket from slipping off the end of the fork tines when the apparatus is inclined. The inboard end of arms 14a through 14d are respectively pivotally mounted at arm pivot bearings 42a through 42d on rear frame members 10a through 10d respectively. In the embodiment shown, hold-down arms 14a and 14b pivot as a unit within arm pivot bearings 42a and 42b whereas the hold-down arms 14c and 14d pivot as a unit in arm pivot bearings 42c and 42d. 
     Arms 14a through 14d are actuated by a linkage mechanism operated by the main lift cable 28. This mechanism has a counterbalance in the form of springs 46a and 46b which act to hold the hold-down arms 14a through 14d in the open position as shown in FIGS. 1, 2 and 4. The main lift line 28 engages a pair of straddle cables 22a and 22b which in turn are connected to lift beam 20 which acts to hold the straddled cables 22a and 22b in the position shown in FIG. 1. The lift beam 20 is connected by means of a pair of clevis elements 25 and 26 to lever arms 30a and 30b. Lever arms 30a and 30b constitute levers of the third class having a fulcrum at pivot 34a and 34b respectively, lift effort at the joint between lift beam 20 and lever arms 30a and 30 b and a load or weight at the ends 35a and 35b respectively. A pair of links 38a and 39a are pivotally attached to the end 35a of lever arm 30a. The links 38a and 39a are in turn pivotally attached to the end of crank arms 50a and 51a with pin 52. Crank arms 50a and 51a are mounted on arm pivot beam 40a and upon application of force from lever arm 30a causes rotation of arm pivot beam 40a about arm pivot bearings 42a and 42b. In turn, arm pivot beam 40a causes hold-down arms 14a and 14b to pivot downwardly since they are rigidly attached to arm pivot beam 40a. Also attached to arm pivot beam 40a is a spring shackle means 44a onto which is mounted a tension spring 46a which extends from spring shackle 44a to lower spring shackle 48a mounted on crossbeam 16. Spring 46a urges arm pivot beam 40a in a clockwise direction when viewed from the near side of the apparatus shown in FIG. 1 thus causing hold-down arms 14a and 14b to assume the position shown in FIG. 1. Spring 46a is of such strength as to prevent the rotation downwardly of arms 14a and 14b when the apparatus is raised without a gabion basket resting on fork tines 11, but readily permits the hold-down arms 14a and 14b to rotate downwardly when the apparatus is lifted with a gabion basket resting on the fork tines 11a  through 11d. 
     In their travel up and down, lever arms 30a and 30b are restrained from side-to-side movement by guide members 36a and 36b comprising a pair of spaced apart, substantially vertical members attached at their lower end to crossbeam 16 and held in position at their upper end by braces 37a and 37b. Similarly, lever arm 30b is guided by guide means 36b which also is held in position by attachment to crossbeam 16 at its lower end and braced by braces 37c and 37d at its upper end. 
     Arms 14c and 14d are operated by a linkage identical to that described above for arms 14a and 14b. Thus, two independently operated sets of hold-down arms are described, each being independently rotatable by lifting forces applied to lift cable 28. 
     The angle at which the loaded gabion basket lifting apparatus assumes may be adjusted by movement of the clevis 25 from the position shown to any of the other positions shown generally by numeral 32 along the length of lever arm 30. This adjustment also provides for different weights and sizes of gabion baskets so that the proper angle will be assumed upon lifting. In FIG. 3, a device carrying a gabion basket is shown in which the approximate center of gravity 80 is shown directly below the main lift line 28. Thus by positioning clevis 25a and 25b at the proper lift position, the angle assumed can be controlled. 
     The apparatus of this invention is equipped with a secondary lift position comprising a secondary lift ring 62 connected to straddle beams 64a and 64b which in turn engage the vertical frame members 10b and 10c at secondary lift pivots 66a and 66b. Usage of this lift location, being positioned relatively rearwardly on the apparatus, permits tilting of the apparatus and removal from beneath the gabion basket such as shown in FIG. 4. Fork tines 11 are removed from contact with the gabion basket 85. The approximate center of gravity of the apparatus when unloaded is shown at 82 causing the equipment to assume the position shown in FIG. 4. 
     Method of Operation 
     In operation, the gabion baskets as shown in FIG. 2 are first placed on a support surface 86 having a pallet or other means for elevating the gabion basket above the support surface 86. The pallet 87 has passages therethrough which permit insertion of fork tines 11 underneath the gabion basket without engaging pallet 87. Rocks or other aggregate are then placed in the gabion basket 85 until the basket is as full as desired. The top of the gabion basket is then wired shut and the entire assembly moved to a position adjacent the stream bed into which the gabions are being placed. The gabion basket lifting and emplacement apparatus is then inserted underneath the gabion basket 85 so that tines 11 are in engagement with the underside of gabion basket 85. The apparatus may be conveniently slid underneath the gabion baskets since the center of gravity of the apparatus as is shown in FIG. 2 is at the location marked 82 directly beneath the main lifting line 28. Thus the apparatus hangs suspended from line 28 with fork tines 11 positioned substantially horizontally. 
     When the gabion basket is located upon the tines 11, tension is applied to main lifting cable 28 and the combined wieght of the apparatus and the gabion basket overcomes the counterbalancing effect of spring 46 and hold-down arms 14a through 14d are rotated downwardly into position above the upper surface and in engagement with the outer surface of a gabion basket 85 whereby the gabion basket 85 cannot slide off tines 11. Further lifting by cable 28 rotates the apparatus and gabion basket into the position shown in FIG. 3 whereby the center of gravity 80 is positioned substantially directly below lift cable 28 and the angle of the tines with respect to the horizontal approximates the slope angle A shown in FIG. 3 of the stream bed prepared to receive the gabion baskets. The loaded apparatus is then swung into the position such as shown in FIG. 3 wherein gabion basket 85 is nestled adjacent another gabion basket 88 and dropped into position against gabion 88. When cable 28 becomes slack, spring 46 causes hold-down arms 14a through 14d to rotate upwardly out of engagement with gabion basket 85 so that the apparatus may be removed from basket 85. At that time, secondary lift cable 60 is hooked into secondary lift ring 62 and tension applied thereto so that the apparatus is lifted away from the gabion basket as shown in FIG. 4. Secondary lift cable 60 is then slackened and released from secondary lift ring 62 so that the primary lift cable 28 may again be utilized to lift and transport the apparatus back to the remaining gabion baskets awaiting emplacement. 
     While the inventor has described his gabion basket emplacement apparatus and method in detail with specific reference to his preferred embodiment, it is apparent that many modifications and substitutions well within the abilities of one skilled in the art may be made to this invention without departing from the scope and spirit thereof. The apparatus may assume variant forms such as, for example, including an adjustability feature so that arm pivot bearings 42a through 42d may be positioned at various locations vertically with respect to fork tines 11a through 11d whereby gabion baskets of various vertical dimensions may be accommodated. Similarly, the lengths of the fork tines 11a through 11d and the hold-down arms 14a through 14d may be varied similarly to accommodate various lengths and widths of gabion baskets. It is apparent also that simple adjustability means may be provided for varying the point of attachment of clevis 25a and 25b at any location along lever 30a and 30b respectively so that precise adjustment of the carrying attitude of the apparatus may be achieved. Other changes and modifications will become apparent to one skilled in the art.