Patent Publication Number: US-10760276-B2

Title: Apparatus and methods for cleaning gutters

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to cleaning means, and, more particularly, to apparatus and methods for cleaning debris from gutters. 
     BACKGROUND OF THE INVENTION 
     While cleaning house gutters of leaves and other debris remains a task that few look forward to doing, failure to do so can cause major issues for a home. Blockages can, for example, cause water to pour over the sides of a gutter and pool around the foundation of the house. This water can cause the foundation to crack and can lead to the growth of mold. In colder weather, a blocked gutter can form an ice dam, a ridge of ice that forms at the edge of a roof and prevents melting snow from draining off the roof. The backed-up water can eventually leak into the home, causing damage to walls, ceilings, insulation, and other areas. 
     Gutters are conventionally cleaned by getting on a ladder and manually removing the debris. Unfortunately, falls from ladders are quite common, and hundreds of injuries and deaths result every year as a result. Solutions that do not require accessing a gutter by ladder typically involve attaching long tubular attachments to leaf blowers, dry vacuums, or pressure washers. However, these attachments remain difficult to use. Almost all gutters include hangers (e.g., bracket hangers, spike-and-ferrule hangers) that transversely span the gutters at regular intervals and act to attach the gutters to their roofs. Conventional attachments get hung-up on these hangers. As a result, the nozzle-end of an attachment must be essentially lifted out of a gutter every time one of these hangers is encountered and then replaced back into the gutter after the hanger is traversed. Such repeated manipulations can be difficult when controlling the distal end of the attachment from the ground via a long run of tubing. 
     For the foregoing reasons, there is a need for new apparatus and methods that allow gutters to be effectively cleaned in an easy and safe manner while addressing the above-identified deficiencies associated with already-existing solutions. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention address the above-identified needs by providing apparatus and methods for cleaning gutters. 
     Aspects of the invention are directed to an apparatus comprising rigid tubing and a tubular nozzle. The tubular nozzle is attached to the rigid tubing and comprises a proximal nozzle portion, a distal nozzle portion, and a guide-shoe. The proximal nozzle portion defines a first proximal nozzle sub-portion merging with a second proximal nozzle sub-portion at a first angle. The distal nozzle portion is removably attached to the proximal nozzle portion and defines a first distal nozzle sub-portion merging with a second distal nozzle sub-portion at a second angle. The guide-shoe projects outwardly from an exterior sidewall of the distal nozzle portion. 
     Additional aspects of the invention are directed to a method of cleaning gutters. An apparatus is obtained that comprises rigid tubing, a tubular nozzle attached to the rigid tubing, a blower, and flexible tubing spanning between the blower and the rigid tubing. The tubular nozzle comprises a proximal nozzle portion, a distal nozzle portion, and a guide-shoe. The proximal nozzle portion defines a first proximal nozzle sub-portion merging with a second proximal nozzle sub-portion at a first angle. The distal nozzle portion is removably attached to the proximal nozzle portion and defines a first distal nozzle sub-portion merging with a second distal nozzle sub-portion at a second angle. The guide-shoe projects outwardly from an exterior sidewall of the distal nozzle portion. In the cleaning method, the tubular nozzle is placed proximate to the gutter. Air is propelled from the blower through the flexible tubing, the rigid tubing, and the tubular nozzle into the gutter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
         FIG. 1  shows a perspective view of a user using an apparatus in accordance with an illustrative embodiment of the invention to remove debris from a gutter attached to a two-story building; 
         FIG. 2  shows a perspective view of the  FIG. 1  apparatus alone; 
         FIG. 3  shows a top perspective view of the tubular nozzle in the  FIG. 1  apparatus; 
         FIG. 4  shows a bottom perspective view of the tubular nozzle in the  FIG. 1  apparatus; 
         FIG. 5  shows a top exploded perspective view of the tubular nozzle in the  FIG. 1  apparatus; 
         FIG. 6  shows a sectional view of the tubular nozzle in the  FIG. 1  apparatus; 
         FIG. 7  shows a side view of tubing subsections in the  FIG. 1  apparatus; 
         FIG. 8  shows an exploded perspective view of the  FIG. 7  elements; 
         FIGS. 9-12  show a sequence of perspective views of the tubular nozzle in the  FIG. 1  apparatus actively cleaning the gutter, with  FIG. 11  showing a magnified perspective view of the tubular nozzle in the region indicated in  FIG. 10 ; 
         FIGS. 13-15  show a sequence of perspective views of the tubular nozzle in the  FIG. 1  apparatus actively being reset in the gutter; and 
         FIG. 16  shows a perspective view of the  FIG. 1  apparatus in addition to an optional attachment in accordance with additional aspects of the invention while cleaning debris from a roof. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention will be described with reference to illustrative embodiments. For this reason, numerous modifications can be made to these embodiments and the results will still come within the scope of the invention. No limitations with respect to the specific embodiments described herein are intended or should be inferred. 
     As used herein and in the appended claims, “substantially” means within plus or minus ten degrees. “Directly” means without an intervening element. An “angle” is meant to mean a non-linear angle. A surface is “curved planar” if the curvature may be conceptually removed from the surface to yield a flat surface without the need to conceptually cut, fold, overlap, or otherwise modify the surface beyond removing its curvature. 
     Aspects of the invention are directed to an apparatus  100  for removing leaves and other debris from rain gutters associated with buildings.  FIG. 1  shows a perspective view of a user  1000  using the apparatus  100  to remove debris  2000  from a gutter  3000  attached to a two-story building  4000 . The apparatus  100  allows the user  1000  to propel pressurized air into the gutter  3000  to cause the debris  2000  therein to be expelled from the gutter  3000  and to fall to the ground. There, it can be safely collected and discarded. The gutter  3000  is thereby cleaned while the user  1000  stays safely on the ground, and issues associated with blockages are avoided by effectively cleaning the gutter  3000 . 
     Additional details of the illustrative apparatus  100  shown in  FIG. 1  are shown in  FIG. 2 , which shows a perspective view of the apparatus  100  alone without other added elements. The apparatus  100  comprises: a blower  105 , flexible tubing  110 , rigid tubing  115 , and a tubular nozzle  120 . The tubular nozzle  120  is attached to the rigid tubing  115 , which, in turn, is connected to the flexible tubing  110 . The flexible tubing  110  is attached to an output of the blower  105  so as to span between the flexible tubing  110  and the rigid tubing  115 . So configured, an interior of the tubular nozzle  120  is in gaseous communication with an interior of the rigid tubing  115  and an interior of the flexible tubing  110 . The blower  105  is thereby able to propel high-velocity air through the flexible tubing  110 , the rigid tubing  115 , and out the tubular nozzle  120 . 
     The tubular nozzle  120  has very novel characteristics that help it to effectively serve its function in cleaning gutters.  FIGS. 3-6  help to illustrate some of these novel characteristics, with  FIG. 3  showing a top perspective view of the tubular nozzle  120  in association with a top of the rigid tubing  115 ,  FIG. 4  showing a bottom perspective view of the tubular nozzle  120 ,  FIG. 5  showing a top exploded perspective view of the tubular nozzle  120 , and  FIG. 6  showing a sectional view of the tubular nozzle  120  along the cleave plane indicated in  FIG. 3 . 
     The tubular nozzle  120  can be conceptually broken down into several portions and sub-portions. A proximal nozzle portion  125  defines a first proximal nozzle sub-portion  130  that merges with a second proximal nozzle sub-portion  135  at a first angle  5000 . At the same time, a distal nozzle portion  140  defines a first distal nozzle sub-portion  145  that merges with a second distal nozzle sub-portion  150  at a second angle  5005 . Both angles  5000 ,  5005  are diagrammatically represented in  FIG. 6 . 
     The distal nozzle portion  140  is removably attached to the proximal nozzle portion  125 . More particularly, the distal nozzle portion  140  defines an insertable region  155  that may be inserted into the distal nozzle portion  140 . At the same time, a threaded rod  160 , a nut  165 , and a clamping handle  170  are implemented to draw the two nozzle portions  125 ,  140  together. A distal end of the threaded rod  160  emerges from a distal hole  175  in the distal nozzle portion  140  and terminates in the nut  165 . A proximal end of the threaded rod  160  emerges from a proximal hole  180  in the proximal nozzle portion  125  and is threaded into the clamping handle  170 , which includes a handle portion  185  and a threaded contact plate  195 . The threaded rod  160  thereby spans between the distal nozzle portion  140  and the proximal nozzle portion  125 . Threading the threaded rod  160  into the clamping handle  170  (i.e., engaging the threaded rod  160  with the clamping handle  170 ) and then rotating the handle portion  185  into its downward position causes an eccentric cam in the clamping handle  170  to place a tensional force on the threaded rod  160 . This tensional force acts to draw the proximal and distal nozzle portions  125 ,  140  together. 
     In addition to holding the proximal and distal nozzle portions  125 ,  140  together, the above-described threaded-rod drawing means also allows the orientation of the distal nozzle portion  140  to be quickly modified in relation to the proximal nozzle portion  125 . Such a modification can be accomplished by manually raising the clamping handle  170  to relieve some of the tension on the threaded rod  160 , and then rotating the distal nozzle portion  140  relative to the proximal nozzle portion  125  about a rotational axis that is colinear with the threaded rod  160 . Once the desired orientation is reached, the clamping handle  170  can again be rotated downward to reapply the requisite tensional force on the threaded rod  160 . In this manner the distal nozzle portion  140  may be removably attached to the proximal nozzle portion  125  with a plurality of different orientations therebetween. 
     In addition to the above-described elements, the tubular nozzle  120  further includes a unique guide-shoe  200 , clearly visible in  FIGS. 3-6 . The guide-shoe  200  projects outwardly from an exterior sidewall of the distal nozzle portion  140 . In the present, non-limiting embodiment, the guide-shoe  200  is u-shaped and is attached to the distal nozzle portion  140  of the tubular nozzle  120  proximate to an output end of the tubular nozzle  120  (i.e., the end furthest from where the tubular nozzle  120  attaches to the rigid tubing  115 ). The guide-shoe  200  defines three exposed surfaces: a curved planar surface  205 , a first flat sidewall  210 , and a second flat sidewall  215 . The curved planar surface  205  and the first flat sidewall  210  form a first curved edge  220 , and the curved planar surface  205  and the second flat sidewall  215  form a second curved edge  225 . 
     The tubular nozzle  120  is attached to a top of the rigid tubing  115  via a larger-diameter section  230  defined by the proximal nozzle portion  125  that slides over the top of the rigid tubing  115 . The larger-diameter section  230  of the tubular nozzle  120  is preferably sized to create a tight compression fit between the two elements  115 ,  120 . One or more rivets or other fixation means (e.g., screws, adhesives, etc.) may also be utilized to hold the two elements  115 ,  120  together, if additional fixation is desired. 
     As indicated above, the tubular nozzle  120  comprises two fixed curves with the first angle  5000  defined by the proximal nozzle portion  125 , and the second angle  5005  defined by the distal nozzle portion  140  ( FIG. 6 ). Extensive experimentation with prototypes of the apparatus  100  have suggested that the first angle  5000  preferably be between about 55 degrees and 65 degrees. The second angle  5005  is preferably between about 60 degrees and 70 degrees. These angles help to allow the user  1000  to easily obtain a comfortable position on the ground while utilizing the apparatus  100  in the manner detailed below (including implementing the tubular nozzle&#39;s various orientations relative to a gutter, again, detailed below). At the same time, these angles are gentle enough to minimize the flow resistance of the high-velocity air passing through the tubular nozzle  120 , while correspondingly also reducing the reaction force acting on the tubular nozzle  120  from the high-velocity air passing therethrough. Less reaction force is thereby transmitted from the tubular nozzle  120  through the rigid tubing  115  to the user  1000 . 
     Like the tubular nozzle  120 , the rigid tubing  115  also comprises sub-parts. More particularly, the rigid tubing  115  is formed of a plurality of removably joined subsections, which allow the effective overall length of the rigid tubing  115  to be modified to meet different applications while, at the same time, allowing the rigid tubing  115  to be transported and stored in a more compacted form.  FIG. 7  shows a side view of a first rigid tubing subsection  245  removably joined to a second rigid tubing subsection  250 , while  FIG. 8  shows an exploded side perspective view of the same elements. The first rigid tubing subsection  245  comprises a smaller-diameter region  255  which slides into (i.e., nests into) a larger-diameter region  260  of the second rigid tubing subsection  250 . At the same time spring-steel strips are used to hold the two rigid tubing subsections  245 ,  250  together. The first rigid tubing subsection  245  includes two first strips  265  attached by first rivets  270  to opposed sides of an exterior surface of the first rigid tubing subsection  245 . Each of the first strips  265  defines a respective slot  275  and is curved at one end. The second rigid tubing subsection  250  includes two second strips  280  attached by second rivets  285  to opposed sides of an exterior surface of the second rigid tubing subsection  250 . Here, each of the second strips  280  defines a respective tab  290 . When the first rigid tubing subsection  245  is slid into the second rigid tubing subsection  250 , the first strips  265  slide over the second strips  280  and ultimately the tabs  290  engage the slots  275  to firmly lock the two rigid tubing subsections  245 ,  250  together. Disengagement of the two rigid tubing subsections  245 ,  250  is as easy as lifting on the curved parts of the first strips  265  to disengage the tabs  290  from the slots  275 , and then pulling the two rigid tubing subsections  245 ,  250  apart. In this manner, constructing the rigid tubing  115  and putting it away in a more compacted form after use may readily be performed manually (i.e., without the use of tools). 
     The blower  105  may comprise any type of equipment capable of providing a source of high-velocity air, such as a conventional leaf blower or a shop vacuum that is capable of blowing in addition to providing a vacuum. The blower  105  in  FIG. 1 , for example, is part of a conventional gas-operated backpack leaf blower, which includes a back unit  295  that provides high-velocity air to a wand assembly  300  ( FIG. 1 ). The wand assembly  300  includes a throttle  305  for modulating the blower  105 . The wand assembly  300  is attached to the flexible tubing  110  in a manner that puts both elements into gaseous communication with each other. 
     In use, the user  1000  may stand safely on the ground next to the building  4000  and place the tubular nozzle  120  proximate to the gutter  3000  to be cleaned. Sufficient numbers of subsections of rigid tubing  115  may be joined to reach gutters associated with the building being cleaned. The user  1000  may then command the blower  105  to propel high-velocity air through the tubular nozzle  120  while manipulating the tubular nozzle  120  in the gutter  3000  to cause debris  2000  therein to be expelled. During use, the user  1000  may grasp the rigid tubing  115  in order to manipulate the tubular nozzle  120  while allowing the flexible tubing  110  to drape (i.e., span) between the user  1000  and the rigid tubing  115  ( FIG. 1 ). 
     Effective gutter cleaning may be accomplished by walking the tubular nozzle  120  forward along the gutter  3000  from a starting point in a single direction and then, if it is felt that the gutter  3000  would benefit from another pass, resetting the tubular nozzle  120  back to the starting point so the process can be repeated. Moving the tubular nozzle  120  in the single direction involves moving the nozzle in what will hereinafter be called the “forward cleaning direction.” Resetting the tubular nozzle  120  involves sliding the tubular nozzle  120  back to the starting point in a direction opposite the forward cleaning direction in what is hereinafter called the “reverse resetting direction.” Notably, the tubular nozzle  120  is designed to be oriented in two different orientations with respect to the gutter  3000  when moving in the forward cleaning direction and the reverse resetting direction; a “forward cleaning orientation” is associated with the forward cleaning direction, while a “reverse resetting orientation” is associated with the reverse resetting direction. The functionality of each orientation will now be described in detail. 
       FIGS. 9-12  show a sequence of perspective views of the tubular nozzle  120  actively cleaning the gutter  3000 , with  FIG. 11  showing a magnified perspective view of the tubular nozzle  120  in the region indicated in  FIG. 10 . In these figures the tubular nozzle  120  is being walked forward by the user  1000  in the forward cleaning direction while the tubular nozzle  120  is oriented in its forward cleaning orientation. The gutter  3000  includes hangers  3005  spaced at regular intervals. 
     As indicated in the Background Section, most gutters include hangers (e.g., bracket hangers, spike-and-ferrule hangers) that transversely span the gutters at regular intervals and act to attach the gutters to their roofs. Conventional attachments get hung-up on these hangers. As a result, the nozzle-end of a conventional attachment must be essentially lifted out of a gutter every time one of these hangers is encountered, and then replaced back into the gutter after the hanger is traversed. Such repeated manipulations can be difficult and fatiguing when controlling the distal end of the attachment from the ground via a long run of tubing. Advantageously the tubular nozzle  120  in the illustrative apparatus  100  addresses these shortcomings. 
     Now referring to  FIG. 9-12 , the tubular nozzle  120  in the forward cleaning orientation is positioned in the gutter  3000  such that air propelled from the tubular nozzle  120  is directed into the gutter  3000  so as to push the debris  2000  in the gutter  3000  forward and out of the gutter  3000  away from the tubular nozzle  120 . At the same time, the unique guide-shoe  200  of the tubular nozzle  120  makes contact with an outside sidewall  3010  (i.e., outside rail) of the gutter  3000 . This contact locks the tubular nozzle  120  in the gutter  3000  and reduces the chance that the tubular nozzle  120  will depart the gutter  3000  in response to the reaction force of the high-velocity air being expelled by the tubular nozzle  120 . 
     When coming upon a hanger  3005 , the guide-shoe  200  makes contact with the hangar, and due to the curvature of the guide-shoe  200 , translates the forward motion of the tubular nozzle  120  into vertical motion that allows the tubular nozzle  120  to readily traverse the hanger  3005 . As the hanger  3005  is encountered, an initial upward motion allows the tubular nozzle  120  to ride up and over the hanger  3005  ( FIGS. 10 and 11 ), and, after the hanger  3005  is bypassed, a subsequent downward motion allows the tubular nozzle  120  to return more deeply into the gutter  3000  ( FIG. 12 ). Thus, the unique guide-shoe  200  imparts vertical motion to the tubular nozzle  120  as hangers  3005  are encountered while moving the tubular nozzle  120  in the forward cleaning direction. During this transversal and while the guide-shoe  200  is imparting the vertical motion, the guide-shoe  200  remains firmly in contact with the outside sidewall  3010  of the gutter  3000 , again assuring that the tubular nozzle  120  does not depart the gutter  3000  due to the thrust of the expelled air. Given these dynamics, all the user  1000  feels when the tubular nozzle  120  encounters a hanger  3005  is an almost imperceptible vertical motion of the tubular nozzle  120 . The tubular nozzle  120  has no tendency to depart the gutter  3000  and the forward travel of the nozzle remains essentially unimpeded, even when encountering one hanger  3005  after the other. 
     Notably, the relative orientation of the distal nozzle portion  140  relative to the proximal nozzle portion  125  can also be altered as desired by the user  1000  when cleaning the gutter  3000  with the apparatus  100 . Such a manual adjustment can be accomplished utilizing the combination of the threaded rod  160  and the clamping handle  170  in the manner set forth above. This ability to reorient the tubular nozzle  120  is a valuable added feature of the apparatus  100 . The orientation may, for example, be quickly changed when reversing the forward cleaning direction relative to the gutter  3000 . At the same time, because of the complicated geometry of the apparatus  100 , variations in the user&#39;s position relative to the gutter  3000  tend to translate into variations in the incident angle of the tubular nozzle  120  on the gutter  3000 . The ability to easily reorient the tubular nozzle  120  ensures that the user  1000  can achieve an effective forward cleaning orientation of the tubular nozzle  120  relative to the gutter  3000  in response to these variations. 
       FIGS. 13-15  show a sequence of perspective views of the tubular nozzle  120  in its reverse resetting orientation relative to the gutter  3000 , conducive to moving the nozzle in the reverse resetting direction. The user  1000  can readily transition the tubular nozzle  120  from the forward cleaning orientation to the reverse resetting orientation by merely twisting the rigid tubing  115  while still safely standing on the ground. 
     As was the case while the tubular nozzle  120  was in its forward cleaning orientation, the unique guide-shoe  200  both helps lock the tubular nozzle  120  into the gutter  3000  and helps the tubular nozzle  120  traverse hangers  3005  while the tubular nozzle  120  is in its reverse resetting orientation. In the reverse resetting orientation, the guide-shoe  200  remains in contact with the outside sidewall  3010  of the gutter  3000 , inhibiting the tubular nozzle  120  from coming loose from the gutter  3000  ( FIG. 13 ). At the same time, when a hanger  3005  is encountered ( FIGS. 14 and 15 ), the shape of the guide-shoe  200  again imparts vertical motion to the rearward traveling tubular nozzle  120 , which acts to lift the tubular nozzle  120  over the hanger  3005  and drop it back down into the gutter  3000  after the hanger  3005  is bypassed. Here again, the user  1000  feels very little resistance from the hanger  3005  as that user  1000  translates the tubular nozzle  120  back to its starting point on the gutter  3000 . Notably, the reverse resetting orientation also provides a convenient means to statically “hang” the tubular nozzle  120  from the gutter  3000  when taking a pause in the cleaning process. 
     Thus, the above-described apparatus  100 , and, more generally, apparatus in accordance with aspects of the invention, provide several advantages over preexisting gutter-cleaning solutions. In particular, the novel shape of the tubular nozzle  120  in combination with its unique guide-shoe  200  provides a means to effectively clean debris from gutters with regularly-spaced hangers without requiring a user to have to manually manipulate the nozzle passed each hanger as they are encountered. Instead, the apparatus  100  is configured to allow the tubular nozzle  120  to essentially slide over these hangers as a result of the vertical motion imparted by the guide-shoe  200  in a manner that is almost imperceptible to the user and while the tubular nozzle  120  remains solidly locked into the gutter. At the same time, aspects of the invention optimally direct a forward-facing source of high-velocity air directly into the gutter so maximum debris removal can be achieved. 
     The above-described means for joining subsections of rigid tubing  115  also provide advantages over prior art solutions such as simple, compression-based joining solutions. The spring-steel strips  265 ,  280  provide positive locking of one rigid tubing subsection to another, but, at the same time, also allow easy disassembly without the need for tools. In this manner, many subsections of rigid tubing may be readily brought to a job site and the ultimate length of rigid tubing tailored to the specific application. Once the job is completed, the run of rigid tubing can be broken back down to its compacted form for easy transport and storage. 
     Elements of the invention may be sourced from commercial vendors and/or manufactured using conventional manufacturing techniques that will be familiar to one having ordinary skill in the relevant arts. A suitable backpack leaf blower may be sourced from, for example, HUSQVARNA® PROFESSIONAL PRODUCTS INC. (Charlotte, N.C., USA). Flexible and rigid tubing (which may be modified with the above-described spring-steel strips) are commercially available from, for example, RIDGID® TOOL COMPANY (Elyria, Ohio, USA). Clamping handles (also called cam handles and clamping levers) capable of acting on threaded rod in the manner indicated above are commercially available from several different vendors, including, as just one example, MCMASTER-CARR® COMPANY (Elmhurst, Ill., USA). 
     A tubular nozzle suitable for use in embodiments of the invention may be formed of a plastic such as, but not limited to, polyvinyl chloride (PVC) using conventional manufacturing techniques. Conventional manufacturing techniques include injection molding, computer-numerical-control (CNC) machining, three-dimensional ( 3   d ) printing, and the like. 
     In one or more additional embodiments falling within the scope of the invention, an optional attachment may be added to the apparatus  100  to allow the apparatus  100  to clean roof surfaces in addition to gutters. Such an optional attachment is represented in  FIG. 16 , which shows a perspective view of the apparatus  100  in addition to an optional attachment  1600  while cleaning debris  5000  from a roof  6000 . The optional attachment  1600  includes a frame  1605 , a pair of casters  1610  attached at opposite ends of the frame, and two u-bolts  1615  that act to removably attach the optional attachment  1600  to the tubular nozzle  120  of the apparatus  100 . 
     With the optional attachment  1600  in place, a user can sweep the tubular nozzle  120  across the roof  6000  while manipulating the tubular nozzle  120  via the rigid tubing  115 . While performing the sweeping motion, high-velocity air from the tubular nozzle  120  can be used to direct the debris  5000  off the roof  6000 . The apparatus  100  with the optional attachment  1600  thereby becomes a means to safely clean a rooftop associated with a building in addition to the building&#39;s gutters. The orientation of the tubular nozzle  120  relative to the frame  1605  and the casters  1610  can be altered to direct the output of the tubular nozzle  120  by simply loosening the u-bolts  1615 , setting the desired orientation, and re-tightening the u-bolts  1615 . If such changes of orientation are frequent, nuts on the u-bolts  1615  can be replaced with cam levers to facilitate loosening and tightening the u-bolts  1615  manually (i.e., without the need for tools). 
     It should again be emphasized that the above-described embodiments of the invention are intended to be illustrative only. Other embodiments can use different types and arrangements of elements for implementing the described functionality. These numerous alternative embodiments within the scope of the appended claims will be apparent to one skilled in the art. 
     All the features disclosed herein may be replaced by alternative features serving the same, equivalent, or similar purposes, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. 
     Any element in a claim that does not explicitly state “means for” performing a specified function or “step for” performing a specified function is not to be interpreted as a “means for” or “step for” clause as specified in AIA 35 U.S.C. § 112(f). In particular, the use of “steps of” in the claims herein is not intended to invoke the provisions of AIA 35 U.S.C. § 112(f).