Patent Publication Number: US-2019198003-A1

Title: Apparatus and method for mitigating dumpster noise

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     Reference is made to and this application claims priority from and the benefit of U.S. Provisional Application Ser. No. 62/610,151, filed Dec. 23, 2017, entitled “APPARATUS AND METHOD FOR MITGATING DUMPSTER NOISE”, which application is incorporated herein in its entirety by reference. 
    
    
     FIELD OF THE INVENTION 
     This disclosure relates generally to trash collection and, more specifically, to an apparatus and method for reducing the noise generated when a dumpster is emptied into a garbage truck. 
     BACKGROUND OF THE INVENTION 
     Trash collection has always been a noisy process. For example, a typical front loader garbage truck has two steel lifting forks projecting in front of the truck cab. The forks are connected to steel linkage arms that extend upwards and backwards over the cab, where they are hinged to the container portion of the truck. The driver pulls up to a dumpster, which is typically made of steel, and guides the lifting forks into metal fork pockets on each side of the dumpster. Once positioned, hydraulic actuators rotate the linkage arms to lift the dumpster upwards over the cab and then tip it upside down over the truck&#39;s container. The contents of the dumpster then empty into the truck container by gravity. Often, the driver will manipulate the hydraulics to rapidly “shake” the dumpster in an upward and downward motion to dislodge any remaining contents of the dumpster. The collection and emptying of the dumpster is notoriously noisy because the dumpster, forks, and fork pockets are all typically fabricated from high strength steel, resulting in metal-to-metal hammering. 
     As a result, trash collection companies, municipalities, and the like strive to schedule garbage collection times when it will have the least impact on their customers. In heavily populated areas, such as urban regions or hotels, scheduling collection at night or very early in the morning is discouraged because it may interrupt a customer&#39;s sleep. Some areas have enacted local ordinances defining “quiet periods,” during which the trash hauler is prohibited from waste collection. However, scheduling garbage collection later in the day may interfere with local traffic patterns or hotel operations. Thus, trash haulers must strike a balance between efficient routing of the garbage trucks and scheduling collection times that do not negatively impact the local community. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the disclosure, a dumpster noise mitigation apparatus includes a lifting fork having a base end configured to attach to a waste collection vehicle, a tip end configured to engage a fork pocket on a dumpster, an upper surface, and a bottom surface. The dumpster noise mitigation apparatus further includes a sound-dampening element secured to one of the upper surface and the lower surface. The sound-dampening element is secured without material removal from the surface of the fork. 
     In one embodiment, the dumpster noise mitigation apparatus further includes a slat secured to the lifting fork, and the sound-dampening element is secured to the slat. 
     In another embodiment, the dumpster noise mitigation apparatus further includes a fork ramp secured to the bottom surface of the tip end of the lifting fork. The fork ramp defines an angled surface extending from the tip end towards the base end. 
     In accordance with another aspect of the disclosure, a method for reducing the noise generated when a dumpster is emptied into a garbage truck includes the steps of providing a slat in the range of 0.5 inches, providing a sound-dampening element having a thickness in the range of 0.10-0.38 inches, securing the slat to one of an upper surface and a lower surface of a lifting fork, and securing the sound-dampening element to the slat. The step of securing the slat to the fork does not entail material removal from the fork surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features described herein can be better understood with reference to the drawings described below. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views. 
         FIG. 1  depicts a side plan view of an exemplary front loader garbage truck positioned to lift a dumpster during a trash collection process; 
         FIG. 2  depicts a side perspective view of a noise mitigation apparatus in accordance with a first embodiment of the present invention; 
         FIG. 3  depicts an enlarged view of the noise mitigation apparatus shown in  FIG. 2 ; 
         FIG. 4  depicts an exploded view of the noise mitigation apparatus shown in  FIG. 2 ; 
         FIG. 5  depicts an enlarged view of the noise mitigation apparatus shown in  FIG. 4 ; 
         FIG. 6  depicts a side perspective view of a noise mitigation apparatus in accordance with a second embodiment of the present invention; 
         FIG. 7  depicts an enlarged view of the noise mitigation apparatus shown in  FIG. 6 ; 
         FIG. 8  depicts an exploded view of the noise mitigation apparatus shown in  FIG. 6 ; 
         FIG. 9  depicts an enlarged view of the noise mitigation apparatus shown in  FIG. 8 ; 
         FIG. 10  depicts a cross-sectional view of the noise mitigation apparatus shown in  FIG. 6 , taken through the plane labeled  10 - 10 ; 
         FIG. 11  depicts a side perspective view of a noise mitigation apparatus in accordance with a third embodiment of the present invention; 
         FIG. 12  depicts an exploded view of the noise mitigation apparatus shown in  FIG. 11 ; 
         FIG. 13  depicts a cross-sectional view of the noise mitigation apparatus shown in  FIG. 11 , taken through the plane labeled  13 - 13 ; 
         FIG. 14  depicts a cross-sectional view of the sound-dampening element shown in  FIG. 13 ; 
         FIG. 15  depicts a side perspective view of a noise mitigation apparatus in accordance with a fourth embodiment of the present invention; 
         FIG. 16  depicts an enlarged view of the noise mitigation apparatus shown in  FIG. 15 ; 
         FIG. 17  depicts a perspective view of a noise mitigation apparatus in accordance with a fifth embodiment of the present invention; 
         FIG. 18  depicts an exploded perspective view of the noise mitigation apparatus shown in  FIG. 17 ; 
         FIG. 19  depicts a block diagram collectively presenting a flow chart illustrating an exemplary embodiment of a process for mitigating noise generated when a dumpster is emptied into a garbage truck; and 
         FIG. 20  depicts a block diagram collectively presenting a flow chart illustrating another exemplary embodiment of a process for mitigating noise generated when a dumpster is emptied into a garbage truck. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The inventor of the present invention studied the garbage collection noise problem by carefully observing the waste collection process and measuring the sound level. A recorded sound level of 108 dB was not uncommon during the data gathering, that level being equivalent to the sound level of a rock concert, and almost 16 times louder than a household vacuum cleaner or TV audio (70 dB). The inventor noted that the fork pockets are purposely oversized, presumably to prevent binding and to accommodate a wide variety of lifting fork configurations. As a result, there is a large clearance—on the order of several inches—between the fork and the inside surfaces of the rectangular pipe. Consequently, as the linkage arms lift and tip the dumpster from a horizontal position to an upside-down position, the dumpster is afforded a large amount of free movement, and the fork pockets loudly hammer against the lifting forks. The dumpster itself can amplify the sound level, since the dumpster is essentially a cavernous metal box structure. Furthermore, operators that rapidly “shake” the dumpster upward and downward to dislodge any remaining contents can further exacerbate the noise level problem. 
     Further study revealed that the majority of contact (e.g., banging) occurred against the top and bottom surface of the lifting fork, and to a smaller degree against the sides of the fork. Embodiments of the present invention provide noise mitigation solutions to the observed interaction between the lifting fork and the fork pocket. 
       FIG. 1  depicts a front loader waste collection vehicle  1  positioned to lift a dumpster  2  during a trash collection process. The dumpster  2  is equipped with two fork pockets  3  on opposing sides of the dumpster. The fork pockets  3  are typically fabricated from rectangular steel tube, and may be welded to the dumpster bin with support struts  4 . The waste collection vehicle  1  includes two opposing linkage arms  5  that extend over the top of the cab, and are hinged to the truck&#39;s refuse container  6 . 
     Referring now to  FIGS. 1-5 , the waste collection vehicle  1  further includes a noise mitigation apparatus  100  to decrease the level of noise generated during the trash collection cycle. The noise mitigation apparatus  100  may include a pair of metal lifting forks  102  projecting in front of the cab of the truck.  FIG. 2  depicts the left (driver&#39;s side) lifting fork  102 , vehicle attachment plate  104 , and bumper  106 . The lifting forks  102  include a base end  108  that secures to the linkage arms  5  (at the point where they connect to the truck), and an opposing tip end  110  that engages the fork pocket  3  of the dumpster  2 . The shape of the lifting forks  102  may vary by vehicle manufacturer, but are generally rectangular, taper from the base to the tip, and are fabricated from steel. 
     In some examples, the tapering cross section of the fork is approximately square in shape, such that the horizontal and vertical cross sections are alike. In other examples, the tapering cross section of the fork is such that the horizontal cross section of the fork is smaller in dimension than the vertical cross section. 
     In the illustrated embodiment of the invention, the lifting forks  102  are tapered along a bottom surface  112  from the base end  108  to the tip of the forks such that the forks&#39; vertical dimension is constantly changing along their length. The fork width (W) remains constant along the length of the forks on any particular truck but the width of the forks may vary from manufacturer to manufacturer. 
     The tip end  110  of the lifting fork  102  may include a rounded nose  114  and a vertically extending lip portion  116  that stops the dumpster fork pocket  3  from sliding off the fork. In one example, the height (H) of the lip portion  116  is approximately 1.50-1.75 inches. 
     The noise mitigation apparatus  100  further includes a sound-dampening element  118  secured to a surface of the lifting fork  102 . In the illustrated embodiment, the sound-dampening element  118  is secured to an upper surface  120  of the lifting fork  102 . However, it is contemplated the sound-dampening element  118  could also be secured to a bottom surface  112  of the fork. 
     In one embodiment of the invention, the sound-dampening element  118  may be fabricated from conveyor belt material, trimmed to the width (W) of the fork and secured with epoxy adhesive. In one example, the belt material may be a multi-ply construction, having an abrasion-resistant upper layer to withstand the day-to-day impacts with the dumpster fork pocket  3 , and a matte or roughened bottom layer for better adhesion. Non-limiting examples of the top layer material may include black rubber, nitrile (NBR) impregnated polyester, or polyvinylchloride (PVC). Non-limiting examples of the bottom layer material may include interwoven fabric, monofilament fabric, polyethylene terephthalate (PET) fabric, or non-woven impregnated polyester. In one example, the conveyor belt material may be approximately 0.1 inches thick. In another example, the conveyor belt material thickness may be in a range between 0.10 and 0.25 inches. The sound-dampening element  118  may be approximately 48 inches in length to substantial cover most of the fork surface. 
     In another embodiment of the invention, the sound-dampening element  118  may be fabricated from a molded material, such as neoprene or fiber-reinforced neoprene. The material may be molded to size or trimmed to the width (W) of the fork and secured with epoxy adhesive. In one example, the molded sound-dampening element  118  may be 0.125 inches thick, with a rubber hardness of Shore 60A, which is similar to the hardness of a car tire tread. The sound-dampening element  118  may be approximately 48 inches in length to substantial cover most of the fork surface. In another example, the sound-dampening element  118  may be formed from Nylon MD, a nylon and molybdenum disulfide (MoS2) composition designed to improve the mechanical, thermal and lubricity properties of type 6/6 nylon. 
     In one example, the sound-dampening element  118  may be secured to the surface of the lifting forks  102  by an adhesive, such as an industrial two-part epoxy adhesive. In other examples, the sound-dampening element  118  may be secured to the surface of the lifting forks  102  by fasteners, or straps. 
     The lifting fork surfaces  120 ,  112  do not require any exceptional preparation prior to application of the sound-dampening element  118 . For example, material removal is not necessary. The lifting fork surfaces  120 ,  112  may be prepped for bonding simply by a thorough cleaning to remove dirt and oils. The sound-dampening element  118  may be applied to the fork surfaces without interfering with the original functionality of the lifting fork, since the material is fairly thin (e.g., 0.1-0.250 inches) compared to, for example, the height (H) of the lip portion  116  (e.g., 1.625 inches). In other words, the thickness of the sound-dampening element  118  may be only 6%-15% of the lip height, which still leaves ample space for the lip portion  116  to perform its function. It is believed the thickness of the sound-dampening element  118  could be as much as 25% of the lip height without adversely impacting the function of the lip portion  116 . 
     Referring now to  FIGS. 6-10 , wherein like numerals indicate like elements in  FIGS. 1-5 , shown is a second embodiment of the present invention in which a noise mitigation apparatus  200  includes a sound-dampening element  218  secured to both an upper surface  220  of the lifting fork  202  and a bottom surface  212  of the lifting fork  202 . This configuration, while more expensive to produce and install than the first embodiment, may provide a marked improvement in sound abatement because it prevents metal-to-metal contact with the fork pocket  3  on both top and bottom surfaces of the lifting forks  202 , even when the dumpster  2  is tipped upside-down and rapidly shook. 
     The sound-dampening element  218  may be similar in construction to that disclosed with reference to  FIGS. 2-5 . That is, in one example, the sound-dampening element  218  may be fabricated from conveyor belt material trimmed to the width (W) of the fork on the bottom surface  212  and the upper surface  220 . The belt material may be a multi-ply construction, having an abrasion-resistant upper layer and a matte or roughened bottom layer. The top layer material may include black rubber, nitrile (NBR) impregnated polyester, or polyvinylchloride (PVC), for example. The bottom layer material may include interwoven fabric, monofilament fabric, polyethylene terephthalate (PET) fabric, or non-woven impregnated polyester, for example. The conveyor belt material thickness may be in a range between 0.10 and 0.25 inches. 
     In another example, the sound-dampening element  218  may be fabricated from a molded material, such as neoprene or fiber-reinforced neoprene. The material may be molded to size or trimmed to the width (W) of the fork (top and bottom) and secured with epoxy adhesive. In one example, the molded sound-dampening element  218  may be 0.125 inches thick, with a rubber hardness of Shore 60A. 
     The sound-dampening element  218 , either the conveyor belt material, molded material, or other material, may be secured to the surface of the lifting forks  202  by an adhesive, such as an industrial two-part epoxy adhesive, or by fasteners or straps. Furthermore, the sound-dampening element  218  may be approximately 48 inches in length to substantial cover most of the upper and bottom fork surfaces. 
       FIG. 10  depicts a cross-sectional view of the noise mitigation apparatus  200  shown in  FIG. 6 , taken through the plane labeled  10 - 10 . The sound-dampening element  218  is shown applied to the upper surface  220  and the bottom surface  212 . In the illustrated example, the sound-dampening element  218  is substantially flush with the side  222  of the lifting fork  202 , so as to not overhang. 
     Referring now to  FIGS. 11-14 , wherein like numerals indicate like elements in  FIGS. 1-5 , shown is a noise mitigation apparatus  300  with a sound-dampening element  318  having a cross-section that takes the form of a channel. The channel is sized to fit snugly over the upper  320  and side  322  surfaces of the lifting fork  302 , and/or the bottom  312  and side  322  surfaces of the lifting forks  302 . In the illustrated embodiment, the channel-shaped sound-dampening element  318  is secured to both the upper surface  320  and the bottom surface  312 . The sound-dampening element  318  may be fabricated from a molded material, such as neoprene or fiber-reinforced neoprene. In one example, the sound-dampening element  318  may be secured to the lifting forks  302  using an industrial two-part epoxy adhesive. The adhesive may be applied to the lifting fork surfaces  312 ,  320 , and the channel-shaped sound-dampening element  318  may be pushed over the fork and allowed to cure. The sound-dampening element  318  may be clamped in place during cure, if needed. 
       FIGS. 13 and 14  depict cross-sectional views of the channel-shaped sound-dampening element  318 .  FIG. 14  includes manufacturing dimensions for one exemplary molded channel, which may be approximately 48 inches long. In the given example, all three sides of the channel  318  are about 0.125 inches thick, and the side members  324  extend approximately 0.75 inches along the side  322  of the fork  302 . 
     Referring now to  FIGS. 15-16 , wherein like numerals indicate like elements in  FIGS. 1-5 , shown is a fourth embodiment of a noise mitigation apparatus  400 . In this configuration, the sound-dampening elements  418  can mitigate noise created in a direction along the longitudinal axis  426  of the lifting fork  402 . In one example, sound-dampening element  418   a  can be secured to the upper surface  420  of the lifting forks  402  as previously disclosed herein. Sound-dampening element  418   b , which may comprise the same material as element  418   a , can be secured to the vertical face  428  of the tip end  410  of the nose  414 . The sound-dampening element  418   b  may be secured in the same manner as element  418   a , for example with industrial two-part epoxy adhesive. In the illustrated example, sound-dampening element  418   b  does not extend vertically farther than the top surface of the tip end  410 , and may be configured to extend less than the top surface (e.g., recessed) so as to assure the sound-dampening element  418   b  does not get peeled or scraped off. One advantage of the additional sound-dampening element  418   b  is that it can mitigate the noise generated when the vertical face  428  of the fork tip end  410  hammers against the front edge of the dumpster fork pocket  3 . 
     In another example, the noise mitigation apparatus  400  may include a sound-dampening element  418   c  that extends along the fork bottom surface  412  as previously disclosed herein, but further includes a segment that at least partially covers the nose portion  414  of the lifting fork  402 . Sound-dampening element  418   c , which may comprise the same material as element  418   a , can be secured in the same manner as element  418   a , for example with industrial two-part epoxy adhesive. Sound-dampening element  418   c  can be adapted to mitigate the noise generated when the lifting forks  402  are not properly aligned and subsequently hit the dumpster fork pocket  3 . Therefore, to prevent the sound-dampening element  418   c  from peeling or shearing away from the nose  414  when the fork  402  hits the fork pocket  3 , in one example the sound-dampening element  418   c  extends about half way up the curved surface of the nose. In another example, the sound-dampening element  418   c  extends approximately one-third up the curved surface of the nose. In yet another example, the sound-dampening element  418   c  extends between one-third and two-thirds up the curved surface of the nose. And, in yet another example, the sound-dampening element  418   c  can extend upwards and cover substantially all of the fork nose  414 . 
     One problem identified in engineering development trials of the disclosed invention was that the adhesive used to secure the sound-dampening element to the lifting forks did not endure as long as hoped. As a result, the sound-dampening element needed to be replaced, and the preparation time required to remove the old adhesive became quite consuming. 
     Experiments were conducted with several combinations of sound-dampening material and commercial adhesives, and although some proved useful and were advantageous for certain applications, a more enduring solution was sought that could be incorporated over a wider range of climate conditions and fork configurations. Furthermore, a sound-dampening element that could be easily removed and replaced was desirable. 
     Referring now to  FIGS. 17-18 , wherein like numerals indicate like elements in  FIGS. 1-5 , shown is a fifth embodiment of a noise mitigation apparatus  500  that solves the above-noted problems. In this configuration, a slat  530  is secured to the upper surface  520  and/or bottom surface  512  of the lifting fork  502 , and a sound-dampening element  518  is secured to the slat. The slat  530  may be configured for long-term or permanent securement to the lifting fork  502 , and the sound-dampening element  518  may be configured for easy removal and replacement. In one embodiment, the slat  530  may be formed of metal, sized approximately the same length and width as the fork upper or bottom surface  520 ,  512 , respectively, and may be at least as thick as required for drilled and tapped threaded holes  532 . In one example, the slat  530  is 48 inches long, 1 inch wide, 0.50 inches thick, and formed from cold-rolled steel. The slat  530  may further define a pattern of equally-spaced ⅜-16 UNC tapped holes  532  to accommodate a fastener  534 , such as a flat head hex socket cap screw. 
     In one embodiment of the invention, the slat  530  may be permanently secured to the lifting fork  502  by welding it along its side edge, as depicted by the weld seam  536  shown in  FIG. 17 . Although the lifting fork  502  may be prepared for welding by lightly grinding the upper and bottom surfaces  520 ,  512  as needed to remove rust, no removal of fork material (i.e., steel) is required in the disclosed embodiment. 
     In one embodiment of the invention, the sound-dampening element  518  may be formed from Nylon MD, a nylon and molybdenum disulfide (MoS2) composition designed to improve the mechanical, thermal and lubricity properties of type 6/6 nylon. The material may be molded to size or trimmed to the width of the fork. In one example, the sound-dampening element  518  is 48 inches long, 1 inch wide, and 0.38 inches thick. The sound-dampening element  518  may further define a pattern of equally-spaced thru holes  538  to accommodate a fastener  534 , such as a flat head hex socket cap screw. In another example, the sound-dampening element  518  may be formed from a molded material, such as neoprene or fiber-reinforced neoprene. 
     Another problem identified in engineering development trials of the disclosed invention was that, in configurations where there was no lip portion  516  on the fork, the sound-dampening element  518  was battered by the forward edges of the fork pocket  3  ( FIG. 1 ) as the fork engaged the pocket. For example, referring to  FIG. 7 , the sound-dampening element on the upper surface of the fork remained intact and held up very well with repeated use. However, the sound-dampening element on the bottom surface abraded and/or delaminated from the fork after repeated use, even when wrapped along the nose, as shown in  FIG. 16 . It is believed the wide variability in which the lifting fork engages the fork pocket (e.g., hitting the upper, lower, or side edges of the pocket) resulted in unanticipated dynamic loads on the sound-dampening element. In some trials, even when the sound-dampening element remained secured to the fork, it abraded to failure. 
     In one embodiment of the invention, the noise mitigation apparatus  500  may further include a fork ramp  540  and to protect the sound-dampening element  518  and alleviate the abrading problem. In the illustrated embodiment, the fork ramp  540  may be positioned where the fork tip  510  transitions to the bottom surface  512 . The fork ramp  540  may include a rounded or angled surface  542  extending from the tip end  510  towards the base end  508 . In one example, the angle may be approximately 30 degrees. The height of the fork ramp  540  may be equal to or greater than the combined thickness of the slat  530  and the sound-dampening element  518 . In one example, wherein the slat  530  is 0.5 inches thick and the sound-dampening element  518  is 0.38 inches thick, the fork ramp  540  may be 1.5 inches long, 1 inch wide, and 0.88 inches high. The fork ramp  540  may be fabricated from steel and welded to the lifting fork  502 , as depicted by the weld seam  536  shown in  FIG. 17 . 
     Although the fork ramp  540  is shown protecting the sound-dampening element  518  on the bottom surface  512 , it can also protect the sound-dampening element  518  on the upper surface  520  if no lip portion  516  is present. 
     Turning now to  FIG. 19 , disclosed is a method  600  for reducing the noise generated when a dumpster is emptied into a garbage truck. At step  610 , a sound-dampening element is provided for securement to the lifting forks. In one example, the sound-dampening element may be fabricated from conveyor belt material, trimmed to the width of the fork. The conveyor belt material may be approximately 0.1 inches thick. In another example, the sound-dampening element may be fabricated from a molded material, such as neoprene or fiber-reinforced neoprene. The molded sound-dampening element may be approximately 0.125 inches thick, with a rubber hardness of Shore 60A. 
     The method  600  for reducing the noise generated when a dumpster is emptied into a garbage truck may include a step  620  to prepare the lifting fork surfaces for the securement of the sound-dampening element. In one example, the forks need only be cleaned of dirt and oils prior to application of an epoxy. 
     The method  600  may further include a step  630  for securing a sound-dampening element to the vertical surface of the fork to end. In one example, the sound-dampening element can be secured with an industrial two-part epoxy adhesive. At the bottom, the sound-dampening element can butt up against the upper surface of the fork. At the top, the sound-dampening element may not extend higher than the flat surface of the tip end of the fork nose. The sound-dampening element may also be recessed from (i.e., lower than) the flat surface of the tip end of the fork nose. 
     The method  600  may further include a step  640  for securing a sound-dampening element to an upper surface of the lifting fork. In one embodiment of the invention, the width of the element is no more than the width of the fork surface, such that there is no overhang. The sound-dampening element may be secured with an industrial two-part epoxy adhesive, strapped, or fastened. In another embodiment of the invention, the sound-dampening element can have a cross-section that takes the form of a channel, such that it fits snugly over the fork surface. 
     The method  600  may further include a step  650  for securing a sound-dampening element to a bottom surface of the lifting fork. In one embodiment of the invention, the width of the element is no more than the width of the fork surface, such that there is no overhang. The sound-dampening element may be secured with an industrial two-part epoxy adhesive, strapped, or fastened. In another embodiment of the invention, the sound-dampening element can have a cross-section that takes the form of a channel, such that it fits snugly over the fork surface. 
     The method  600  for reducing the noise generated when a dumpster is emptied into a garbage truck may include a step  660  to extend the sound-dampening element so as to at least partially cover the forward nose portion of the lifting fork. The sound-dampening element may extend about one-third up the curved surface of the nose. In another example, the sound-dampening element may extend approximately half way up the curved surface of the nose. In yet another example, the sound-dampening element may extend upwards and cover substantially all of the fork nose. 
     The method  600  may further include a step  670  to cure the industrial two-part epoxy adhesive. During the curing step, the sound-dampening element may be temporarily clamped to assure proper adhesion. 
     Turning now to  FIG. 20 , disclosed is a method  700  for reducing the noise generated when a dumpster is emptied into a garbage truck. At a step  710 , a slat is provided for permanent securement to the lifting forks. The slat may be formed from cold-rolled steel, sized approximately the same length and width as the fork upper or bottom surface, and may be at least as thick as required for drilled and tapped threaded holes. 
     At a step  720 , a sound-dampening element is provided for securement to the slat. In one example, the sound-dampening element may be fabricated from Nylon MD, trimmed to the length and width of the fork, and may be approximately 0.38 inches thick. The sound-dampening element may further define a pattern of equally-spaced thru holes to accommodate a fastener, such as a flat head hex socket cap screw. 
     The method  700  may further include a step  730  of providing a fork ramp and a step  740  of securing the fork ramp to the fork. In one example, the fork ramp may be positioned where the fork tip transitions to the bottom surface. The fork ramp may include a rounded or angled surface extending from the tip end towards the base end. In one example, the angle may be approximately 30 degrees. The fork ramp may be welded to the lifting fork along its side edge. 
     The method  700  may further include a step  750  for securing the slat to the bottom surface of the lifting fork. In one example, the slat may be permanently secured to the lifting fork by seam welding along its side edges. 
     The method  700  may further include a step  760  of securing the sound-dampening element to the slat. In one example, the securement is provided by flat head hex socket cap screws. 
     One of the improvements of the disclosed noise mitigation apparatus and method is that the noise generated during dumpster emptying can be reduced by about 10 dB, or 50%. This significant reduction can allow trash haulers to open their schedules and thereby schedule routes more efficiently. 
     While the present invention has been described with reference to a number of specific embodiments, it will be understood that the true spirit and scope of the invention should be determined only with respect to claims that can be supported by the present specification. Further, while in numerous cases herein wherein systems and apparatuses and methods are described as having a certain number of elements it will be understood that such systems, apparatuses and methods can be practiced with fewer than the mentioned certain number of elements. Also, while a number of particular embodiments have been described, it will be understood that features and aspects that have been described with reference to each particular embodiment can be used with each remaining particularly described embodiment.