PIPELINE PADDING APPARATUS Technical Field l. Field of the invention. This invention relates to cross country pipeline construction and more particularly to a screening apparatus for screening rock and other debris from ditch backfill soil and simulta- neously applying the desired screened padding material to a pipeline or cable in a ditch. To maximize the life of a buried pipeline or cable it is required that the initial covering or burying of a pipeline or cable in a ditch be done with relatively fine earth, namely screened earth from which rocks and other debris have been removed. A trench containing a line is filled to a given depth with fine screened earth or sand. This screened earth is preferably obtained from the excavated earth normally used in backfilling a ditch. However, in rocky terrain it is necessary that this earth be screened, as mentioned herein above, to remove objectionable material which might damage the buried line if placed in contact therewith in the ditch or trench. Since the backfill or excavated earth must be used or removed from the trench site, it is highly preferable that this backfill earth be utilized in obtaining the screened earth for initially filling the bottom portion of the trench. In many locations, the excavated earth is placed along one side parallel with the trench and the opposite side of the

trench is used as a working area for the line laying machines or other equipment. In rough terrain, the backfill or excavated earth side of the ditch is sometimes limited in space making it difficult if not impossible for a backfilling machine to operate on that side of the ditch. This invention provides a screened bottom bucket attached to the end of a boom in backhoe fashion and operated by a prime mover moving along the working side of a ditch. Background Art The prior art is crowded with machines in which their structure requires them to operate on the backfill soil side of the ditch. In plains areas this presents no problem but in rough terrain or mountainous areas it many times is impractica- ble if not impossible. Of the numerous patents the following are considered most pertinent. United States patent No. 3,732,980 issued May 15, 1973 to Evers et al for EARTH MOVING AND SCREENING EQUIPMENT discloses a screen for use on buckets operated by a front end loader or the like. The screen forms the bight portion of an U-shaped frame which straddles the bucket and is moveable to position the screen beneath the bucket when in a soil dumping action and an upward elevated out-of-the-way position when not used for screening. The screen being vibrated when in a soil screening position. United States patent No. 4,157,956 issued June 12, 1979 to Robinson for SCREENING BUCKET discloses a two part bucket mounted on the forward end of a prime mover in which the two parts of the bucket are separable to form a downward opening through which soil or other matter picked up by the bucket may be released. A reel wound web mounted rearwardly of the bucket is connected to the forward half thereof and is payed out across the opening formed by spreading the halves apart to screen material falling therethrough when the bucket is in open position. Bucket supporting arms may be intermittently activated to shake the screen and enhance the screening action. United States patent No. 3,003,265 issued October 10, 1961 to Lutjens for BUCKET DEVICE discloses a front end loading bucket having a substantially bucket shaped screen frame for covering the bucket open end in which the screen is pivoted to the top

open edge of the bucket and normally held in a raised out-of- the-way position until the bucket is filled and then the screen is inverted for finer soil to fall through the bars of the screen. United States patent No. 4,664,791 issued May 12, 1987 McClain et al for PADDING MACHINES discloses a carriage mounted laterally of a tractor moving along one side of a ditch containing a pipeline to be padded. The carriage supports a hopper having a vibratory screen at its depending end which screens soil to be placed over the pipe in the ditch. The hopper is periodically filled by a second machine such as a backhoe accompanying the tractor. Screened out material is deposited laterally of the ditch opposite the position of the tractor. Disclosure of the Invention This invention provides a backhoe operated bucket having its wall area opposite its bucket filling opening removed and a vibrating screen apparatus inserted therein so that when the bucket is filled and disposed with its earth receiving opening upward over a ditch and the screen vibrated, screened padding material falls into the ditch. The bucket is formed by parallel end walls with side walls diverging toward its earth receiving blade equipped loading opening. The back bottom wall area of the bucket opposite its loading opening is open and contains a vibratable screen supported by resilient mounts and vibrated by a motor driven eccentric. Backhoe boom attaching fins are secured to the outer surface of the bucket side wall opposite its blade equipped wall.

Brief Description Of The Drawinσs Figure 1 is an elevational view partly in section illustrat- ing the apparatus in operation on the end of a backhoe boom; Figure 2 is an exploded isometric view of the bucket illustrating the vibrator screen in the bottom opening by dotted lines and in exploded relation by solid lines; Figure 3 is a isometric view of the bucket frame, per se, to a smaller scale; Figure 4 is a isometric view of one screen vibrator, per se; and,

Figure 5 is a vertical cross section view taken substantially along the line 5 5 of Fig. 2. Best Mode For Carrying Out The Invention Referring first to Figure 1, the reference numeral 10 indicates the apparatus mounted on the end of hydraulically operated booms 12 and 13 of a substantially conventional backhoe apparatus 14 positioned on the working side 15 of a pipeline ditch 16 having a pipeline 18 in the bottom thereof to be covered with fine earth padding material 20 from the ditch excavated backfill soil 22. Referring also to the remaining Figures, the apparatuε 10 comprises a unitary backhoe bucket 24 and a rectangular screen support frame 26, the frame 26 having elongated end members 28 and 29 joined with longitudinally extending elongated members 30 and 31. Bucket end walls 32 and 33 are joined in parallel relation to the support frame end walls 28 and 29, respec- tively. Bucket side walls 34 and 35 are similarly joined along one edge to the support frame side members 30 and 31, respectively, and project in diverging relation therefrom and are secured at their respective end edges to the edges of the bucket end walls 32 and 33, respectively. Thus, defining a bucket fill opening opposite the support frame 26 which is characterized by a coextensive scraper blade 36 longitudinally secured to the bucket wall 35 along its edge opposite the support frame 26. A pair of planar fins 38 are secured in edgewise parallel spaced apart relation to the outer surface of the bucket wall 34 medially its ends which act as a stiffener for the bucket side wall 34 and are line drilled, as at 40 and 42, to form two pairs of openings which respectively receive backhoe boom pins 41 and 43 permitting the backhoe operator to manipulate the bucket 24 in a manner conventional with backhoe operation. The bucket is transversely divided medially its ends by a wedge shaped partition 44 having its apex 45 disposed in the plane defined by the bucket end and side walls marginal edge opposite the support frame 26. The bucket walls are also further strengthened by a coextensive inturned lip 46 secured to the screen support frame 26, at its juncture with the bucket side and end walls, which

also includes a transverse panel 48 overlying base edge of the wedge shaped partition 44. The screen support frame 26 loosely receives a vibratable elongated rectangular screen frame 50 formed by parallel end members 52 and 53 joined by elongated side members 54 and 55. The frame 50 is loosely mounted within the support frame 26 by stud bolts 56 projecting through the respective frame wall and entering resilient mounts 58 strategically located between confronting surfaces of the walls of the support frame 26 and screen frame 50. Each of the resilient mounts 58 comprises a section of resilient material 60, such as rubber, having a pair of plates 62 and 64 flatly secured to its opposing surfaces. Each of the plates being provided with threaded sockets 66 which cooperatively receive the stud bolts 56. Medially its ends the screen frame 50 is transversely divided by a pair of parallel spaced apart panels 67 joined by a companion panel 68 which form in combination with frame longitudinal members 54 and 55 an open box which cooperatively nests a vibrator assembly 70 (Fig. 4), as presently described in further detail. Each end porjtion of the screen frame 50 between its respective end wall and the adjacent central panel is longitudinally and transversely provided with interlocking brace members 72 and 74 to strengthen the frame 50 and provide screen support surfaces in the plane of the marginal edge of the screen frame 50 opposite the bucket frame 24. A screen 76, of selected mesh, dimensioned to be coextensive with the area defined by the marginal edges of the end and side walls of the frame 50 is secured to its edge surface and brace members 72 and 74 opposite the bucket 24. The vibrator assembly 70 comprises an eccentric 78 mounted on a shaft 80 journalled at its respective end portions by pillow block bearings 82 secured to the screen frame panel 68 (Fig. 2). A coupling 84 joins the shaft 80 to the drive shaft of a hydraulic motor 86 similarly mounted on the panel 67 and provided with hydraulic couplings. Operation In operation the backhoe is positioned at the working side 15

of the pipeline ditch 16, opposite the excavated soil 22, and its boom arms 12 and 13 are extended across the ditch and manipulate the bucket 24 in a soil pick-up action by its cutting blade 36 in a conventional manner. The filled bucket 24 is then tilted to position its front opening edge upwardly and the screen frame 50 downwardly, as illustrated by Fig. 1, over the position of the ditch 16. With the vibrator motor 86 operating the eccentric 78 the screen assembly 50 is longitudi- nally and vertically vibrated . The fine padding soil 20 falls by gravity over the pipeline 18. When sufficient padding covers the pipeline the screened out rock or other debris in the bucket 24 is released into the ditch as backfill over the padding material by inverting the bucket from the position shown in Fig. 1, thus, completing one cycle of operation.