Patent Publication Number: US-7896094-B2

Title: Beach cleaner

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2006-100481, filed Mar. 31, 2006, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a beach cleaner for collecting various kinds of litter scattered in sand ground such as bathing beach. 
     2. Description of Background Art 
     As such a beach cleaner, there is known a device including a frame, a scraper, and a mesh member. The frame is constituted by a plurality of longitudinal members each extending along a direction of traveling and a plurality of transverse members each extending in a transverse direction or substantially perpendicularly to the longitudinal members. The scraper is disposed in a front portion of the frame, and the mesh member is disposed in a rear portion of the frame. While the beach cleaner is traveling over a surface of sand ground by being towed by a towing vehicle with the scraper being partially sunk in the sand, litter of relatively small size are churned up along with sand so that the litter and sand churned up are captured and deposited in the mesh member. See JP-A No. 2002-356827, for instance. 
     In the thus constructed beach cleaner, the mesh member is detachably attachable to the frame, and selected from a plurality of kinds with different mesh sizes, depending on the conditions of the sand and litter. 
     However, it is anticipated that a fine mesh member undesirably tends to inhibit the scraped sand from falling therethrough, while a rough mesh member undesirably allows the litter to fall therethrough. There is a demand for removing this drawback. 
     SUMMARY AND OBJECTS OF THE INVENTION 
     The invention provides a beach cleaner which scrapes up litter along with sand and captures them by a mesh member, wherein the sand reaching the mesh member is allowed to easily fall while the litter is inhibited from falling. 
     To address the above issue, according to a first aspect of the present invention, a beach cleaner (e.g., the second beach cleaner  50  in the embodiment) includes a frame (e.g., the frame  53  in the embodiment) including a plurality of longitudinal members (e.g., the longitudinal members  51  in the embodiment) each extending along a traveling direction of the beach cleaner, and a plurality of transverse members (e.g., the transverse members  52   a  and  52   b  in the embodiment) each extending in a transverse direction of the beach cleaner such that the transverse members extend substantially perpendicularly to the longitudinal members. 
     In addition, a churn-up portion (e.g., the keel members  54  and the scraper  55  in the embodiment) is disposed in a front portion of the frame; a mesh member (e.g., the mesh member  56  in the embodiment) is disposed in a rear portion of the frame; and a tow portion (e.g., the tow portion  67  in the embodiment) is disposed at a front end portion of the frame. The churn-up portion churns up litter scattered on sand ground, along with sand, while the beach cleaner (e.g., the second beach cleaner  50  in the embodiment) is traveling on a surface of the sand ground by being towed by a towing vehicle (e.g., the vehicle  1  in the embodiment), and the churned up litter is deposited in the mesh member, the mesh member having an encircling member (e.g., the encircling member  91  in the embodiment) open at least at a side. Further, the mesh of the mesh member is relatively rough at a front portion thereof in the traveling direction, and the mesh is finer at a rear portion thereof in the traveling direction than that of at least the front portion. 
     According to a second aspect of the present invention, the mesh member is shiftable relative to the frame in a front-rear direction. 
     EFFECT OF THE INVENTION 
     According to the first aspect of the present invention, relatively heavy and damp sand is well sieved off to fall through the relatively rough mesh at the front portion of the mesh member in the traveling direction. On the other hand, relatively light and dry sand reaches the rear portion of the mesh member in the traveling direction along with litter of relatively small size, and is sieved off to fall through the relatively fine mesh, while the litter does not tend to fall therethrough but is caught excellently. That is, irrespective of the conditions of the sand and litter, the sand reaching the mesh member is allowed to easily fall while the litter is inhibited from falling, thereby enhancing the capability of the beach cleaner to collect litter. 
     According to the second aspect of the present invention, the position of the mesh member is shiftable relative to the frame in the front-rear direction, depending on the state of scraping up of sand and litter, thereby allowing the sand to fall further easily and inhibiting the litter from falling more strictly. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
         FIG. 1  is a side view of beach cleaners according to an embodiment of the invention and being transported by being mounted on a trailer together with other devices; 
         FIG. 2  is a side view of a first beach cleaner according to the embodiment; 
         FIG. 3  is a top view of the first beach cleaner shown in  FIG. 2 ; 
         FIGS. 4(   a ) and  4 ( b ) are explanatory views of a sand pin of the first beach cleaner, in which  FIG. 4(   a ) is a side view and  FIG. 4(   b ) is a view as seen in the direction of arrow A in  FIG. 4(   a ); 
         FIGS. 5(   a ) and  5 ( b ) are explanatory views of a modification of the sand pin, in which  FIG. 5(   a ) is a side view and  FIG. 5(   b ) is a view as seen in the direction of arrow A in  FIG. 5(   a ); 
         FIG. 6  is a side view of the first beach cleaner with a weight mounting portion attached thereto; 
         FIG. 7  is a top view corresponding to  FIG. 6 ; 
         FIG. 8  are explanatory views of the weight mounting portion shown in  FIG. 6 , in which  FIG. 8(   a ) is a top view and  FIG. 8(   b ) is a side view thereof; 
         FIG. 9  is an explanatory exploded view showing the weight mounting portion shown in  FIG. 6  and a weight attached thereto; 
         FIG. 10  is a side view showing a weight mounting portion as attached to a front carrier of a towing vehicle; 
         FIG. 11  is a top view corresponding to  FIG. 10 ; 
         FIG. 12  is an explanatory exploded view showing the weight mounting portion shown in  FIG. 10  and a weight attached thereto; 
         FIG. 13  is a side view of a litter collecting station according to the embodiment; 
         FIG. 14  is a top view corresponding to  FIG. 13 ; 
         FIG. 15  is an explanatory perspective view of a dividable structure in the litter collecting station; 
         FIG. 16  is a side view of a second beach cleaner according to the embodiment; 
         FIG. 17  is a top view corresponding to  FIG. 16 ; 
         FIG. 18  is a rear view corresponding to  FIG. 16 ; 
         FIG. 19  is a side view of a front portion of a frame of the second beach cleaner; 
         FIG. 20  is a view as seen in the direction of arrow A in  FIG. 19 ; 
         FIG. 21  is a side view of a hinge for a mesh member of the second beach cleaner and its vicinity; 
         FIGS. 22(   a ) and  22 ( b ) are views as seen in the direction of arrow A and arrow B in  FIG. 21 , respectively; and 
         FIGS. 23(   a ) and  23 ( b ) represent a case where the mesh member of the second beach cleaner is made movable in a front-rear direction, and are side views of the mesh member at a retracted position and at an advanced position, respectively; 
         FIG. 24  illustrates a path along which the vehicle travels when a sandy beach is cleaned using the beach cleaners of the embodiment; 
         FIG. 25  is a side view of the first beach cleaner as towed by the vehicle; and 
         FIG. 26  is a side view of the second beach cleaner as towed by the vehicle. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A vehicle  1  shown in  FIG. 1  has a small-sized and lightweight body, and left and right front wheels  2  and left and right rear wheels  3  which are low pressure balloon tires of relatively large diameter. The front and rear wheels  2 ,  3  are disposed at a front portion and a rear portion of the body, respectively. The vehicle is provided by a so-called ATV (All Terrain Vehicle) the running performance of which especially in rough terrain is improved by setting large the ground clearance of the vehicle. A body frame  4  of the vehicle  1  has a box-like shape long in a front-rear direction at a middle portion in a transverse direction of the vehicle. In a substantially middle portion of the vehicle body frame  4 , an engine  5  as a motor of the vehicle  1  is installed. 
     The engine, which may be a water-cooled single cylinder engine, for instance, outputs a torque of a crankshaft to front and rear propeller shafts  6   a ,  6   b  via a transmission of meshing gear type. The torque transmitted to the front and rear propeller shafts  6   a ,  6   b  is outputted to the front and rear wheels  2 ,  3  via front and rear reduction gears  7   a ,  7   b , respectively. 
     The vehicle  1  is of so-called semi-automatic transmission type where the gear ratio of the transmission can be electronically changeable. For instance, where a centrifugal clutch is interposed, the gear ratio can be changed merely by manipulation of a change button or others without an operator bothering to operate a clutch. Such a vehicle  1  is more suitable for traveling with high traveling load and traveling at a constant speed. 
     The front left and right wheels  2  are suspended in a front portion of the body frame  4  by means of a front suspension  8   a  of single wheel suspension type. The rear left and right wheels  3  are suspended in a rear portion of the body frame  4  by means of a rear suspension  8   b  which may be of swing arm type, for instance. At a rear end portion of a swing arm  9  of the rear suspension  8   b , a trailer hitch  11  for towing a trailer is disposed. Reference numerals  12   a  and  12   b  in the drawings respectively denote a front carrier supported at the front portion of the body frame  4  and a rear carrier supported at the rear portion of the body frame  4 . 
     The vehicle  1  can tow first and second beach cleaners  20 ,  50 , which will be described later, and a trailer  13  for carrying a litter collecting station  40 . 
     For instance, the trailer  13  is constructed to have a body frame  14 , a pair of wheels  15 , i.e., a left wheel and a right wheel, a carrier  16  disposed on the body frame  14 , and a tow arm  17 . The left and right wheels are disposed at two opposed sides of a lower portion of the body frame  14 , and the carrier  16  have a vertically thin box-like shape open at the upper side. The tow arm  17  extends frontward from the under side of a front portion of the body frame  14 . At a front end portion of the tow arm  17 , a hitch coupler  17   a  which is to engage the trailer hitch  11  is disposed. 
     On an upper surface of the carrier  16  and at left and right ends at each of a front side and a rear side, a receiving member  16   a  for supporting each of connecting pipes  46  (described later) of the litter collecting station  40  is disposed. Each of the receiving members  16   a  has a V-shaped recess open upward. The connecting pipes  46  of the litter collecting station  40  as inverted and mounted on the trailer  13  are fitted in the recesses to be held thereby. On the litter collecting station  40  as inverted and mounted on the trailer  13 , the second beach cleaner  50  is mounted, for instance in a state where the second beach cleaner  50  is engaged with a ground-contact member  43  and thus restricted from displacing, and the first beach cleaner  20  is mounted, for instance in a state where the first beach cleaner  20  is accommodated in the carrier  16 . 
     It is noted that each of the beach cleaners  20 ,  50  and the litter collecting station  40  is in the state mounted on the trailer  13  in  FIG. 1 , but is in use on sand ground in  FIG. 2  and the following drawings unless otherwise noted. In some drawings, line GL represents the ground surface (or upper surface of the sand), and line CL represents a transverse centerline of the vehicle  1 , the beach cleaners  20 ,  50  towed thereby, and the litter collecting station  40  through which the vehicle  1  and the beach cleaners  20 ,  50  pass. (Hereinafter, the vehicle  1 , the beach cleaners  20 ,  50 , and the litter collecting station  40  may be collectively referred to as “vehicle and other devices”.) Arrow FR indicates the front side in the traveling direction (or front-rear direction) of the vehicle and other devices, arrow UP indicates the upper side in the vertical direction of the vehicle and other devices, and arrow LH indicates the left side in the transverse direction of the vehicle and other devices. 
     Each of the beach cleaners  20 ,  50  is towed by the vehicle  1  to travel in a sand ground, such as one at seacoast (sandy beach), during which the beach cleaner  20 ,  50  picks up various kinds of litter scattered on the sand. The litter picked up by the beach cleaners  20 ,  50  are collected together into the litter collecting station  40  which is installed at a place in the sand ground. Each of the beach cleaners  20 ,  50  and litter collecting station  40  is produced by suitably assembling a plurality of kinds of steel products, such as those of stainless steel, by a combining method such as welding. It may be arranged such that each of the beach cleaners  20 ,  50  is towed by a tractor. 
     As shown in  FIGS. 2 and 3 , the first beach cleaner  20  is constructed such that a plurality (e.g.,  15 ) of longitudinal members  21  each extending along the traveling direction are arranged in the transverse direction (or left-right direction) at regular intervals to form a frame  22  like a duckboard, and a plurality of sand pins  23  are detachably attached to each of the longitudinal members  21  such that the sand pins  23  protrude downward. The first beach cleaner  20  is constructed symmetrically in the transverse direction. 
     Each of the longitudinal members  21  is provided by a circular steel tube (or alternatively a rectangular steel tube) disposed to extend in the front-rear direction and having a front end portion bent obliquely up frontward or backward. A plurality of such longitudinal members  21  are arranged in the left-right direction to entirely overlap one another in side view. Front ends of the longitudinal members  21  are abutted and joined, from the obliquely rear lower side, to a front transverse member  24   a  extending along the left-right direction, which may be a rectangular steel tube. Rear ends of the longitudinal members  21  are abutted and joined, from the obliquely front lower side, to a rear transverse member  24   b  extending along the left-right direction, which may be a rectangular steel tube. 
     The frame  22  constituted by the longitudinal members  21  and the transverse members  24   a ,  24   b  has a rectangular shape long in the transverse direction in top view. The transverse dimension of the frame  22  is equal to or slightly larger than the transverse dimension of the vehicle  1 , and smaller than the transverse dimension between a left side structure  41  and a right side structure  41  of the litter collecting station  40  which will be described later. 
     It is arranged such that the sand pin  23  can be attached to each longitudinal member  21  at each of a front portion, a middle portion, and a rear portion thereof. That is, a plurality of sand pins  23  can be disposed in three rows, i.e., a front row, a middle row, and a rear row. According to this arrangement, the travel resistance during traveling at low speed is lowered, and it is possible to further lower the travel resistance by reducing the number of the sand pins  23  depending on the firmness of the sand ground surface. The amount of protrusion of the sand pins  23  from an under surface of the frame  22  is set at 100 mm at most so as to reduce the impact to the ecosystem in the sand. 
     When the thus constructed first beach cleaner  20  travels in the sand ground, relatively large-sized litter scattered (ropes, nets, driftwood, and others) are raked by being caught at or entangled around the sand pins  23 . 
     Referring further to  FIG. 4 , each sand pin  23  has a plate-like member  25  curved to fit an outer surface of a lower portion of the longitudinal member  21 , a pin main body  26  vertically extending through the plate-like member  25 , and a brace-like support member  27  extending between a lower portion of the pin main body  26  and a rear portion of the plate-like member  25 . The sand pin  23  has a triangular shape narrower on the lower side in side view. An upper portion of the pin main body  26  is formed as an externally threaded portion  26   a . With the externally threaded portion  26   a  being inserted through the longitudinal member  26  from the under side to protrude upward from the longitudinal member  21 , the plate-like member  25  is contacted with an under surface of the longitudinal member  21 . In this state, a cap nut  28  is threadably mounted on the externally threaded portion  26   a  and tightened, thereby fixing the sand pin  23  on the longitudinal member  21 . At a position in the longitudinal member  21  where the pin main body  26  extends through, a cylindrical collar  29  is inserted and fixed. 
     As  FIG. 5  shows, where the longitudinal member is provided by a rectangular steel tube  21 ′, a sand pin  23 ′ corresponding thereto is employed. That is, the sand pin  23 ′ has a plate-like member  25 ′ which is square U-shaped in cross section in order to fit an outer surface of a lower portion of the longitudinal member  21 ′. With the plate-like member  25 ′ fitted on the lower portion of the longitudinal member  21 ′, the cap nut  28  is threadably mounted on the externally threaded portion  26   a  and tightened, thereby fixing the sand pin  23 ′ on the longitudinal member  21 ′. The width of a cross-sectional shape of the longitudinal member  21 ′ in the left-right direction is relatively large so as to improve the slidability of the first beach cleaner on sand ground. In a case where a lower end portion of the pin main body  26  is bent frontward to form a bent portion  26   b , the capability of collecting litter is further enhanced. 
     As  FIGS. 6 and 7  show, on the frame  22  of the first beach cleaner  20 , there can be disposed a weight mounting portion  31  for adjusting an amount of sinking of the sand pins  23  into the sand. 
     Referring further to  FIG. 8 , the weight mounting portion  31  is constructed such that two base members  32  arranged in the left-right direction are integrally connected by means of a support bracket  33 . Each base member  32  is provided by a longitudinal member long in the front-rear direction. The base members  32  are interspaced from each other in the left-right direction by the same distance as the distance of two adjacent longitudinal members  21  of the frame  22  in the left-right direction. In each of a front end portion and a rear end portion of each base portion  32 , there is formed an insertion hole  32   a  through which the externally threaded portion  26   a  of a corresponding one of the sand pins  23  that are attached to the frame  22  in the front-rear direction arrangement. The support bracket  33 , which has a square U-shaped cross-sectional shape open rearward and extends in the left-right direction, is disposed to extend across longitudinally middle portions of the base portions  32 . 
     The weight mounting portion  31  constructed as described above can be attached to the frame  22  at the position corresponding to the sand pins  23 , by screwing using the sand pin  23 . However, even at a position not corresponding to the sand pins  23 , the weight mounting portion  31  can be attached by using suitable bolts or others. Thus, the number of the weight mounting portion(s)  31  mounted on the frame  22  and the position(s) on the frame  22  at which the weight mounting portion(s)  31  is/are mounted are not limited. 
     Referring further to  FIG. 9 , a weight  34  supported by the weight mounting portion  31  has a block construction having a lower block  34   a  fitted in the support bracket  33  from the rear side and an upper block  34   b  fitted on the lower block  34   a  from the upper side. 
     With a front end portion of the lower block  34   a  being disposed inside the support bracket  33 , the lower block  34   a  is connected and fixed to the support bracket  33  by means of an engaging pin  35   a  vertically inserted through the front end portion of the lower block  34   a  and the support bracket  33 . With a lower portion of the upper block  34   b  fitted on an upper portion of the lower block  34   a , the upper block  34   b  is connected and fixed to the lower block  34   a  by means of a connecting bolt  35   b  vertically inserted through the upper and lower blocks  34   a ,  34   b.    
     As  FIGS. 10 and 11  show, a predetermined weight mounting portion  31 ′ can be disposed on the front carrier  12   a  of the vehicle  1  so that even where the travel resistance increases due to the weight  34  mounted on the first beach cleaner  20  or for other reasons, the load on the front wheels is sufficiently high to give sufficient driving force. 
     The weight mounting portion  31 ′ is constructed such that a support bracket  33  similar to that of the weight mounting portion  31  described above is integrally disposed on a base portion  32 ′ conforming to an upper surface of the front carrier  12   a . The base portion  32 ′ is a plate-like member oblong rectangular in top view, and detachably attached, at the under side of a front portion and a rear portion thereof, to pipe members of the front carrier  12   a  extending in the left-right direction. 
     Referring further to  FIG. 12 , a weight  34 ′ supported by the weight mounting portion  31 ′ has a block construction having a lower block  34   a ′ fitted in the support bracket  33  from the rear side and the upper block  34   b  fitted on the lower block  34   a ′ from the upper side. 
     In the lower block  34   a ′, an amount of rearward extension is slightly increased as compared with the lower block  34   a , and a front end portion of the lower block  34   a ′ is connected and fixed to the support bracket  33  by means of the engaging pin  35   a . With a lower portion of the upper block  34   b  fitted on a rear portion of an upper portion of the lower block  34   a ′, the upper and lower blocks  34   a ′,  34   b  are connected and fixed to each other by means of the connecting bolt  35   b . The weight of the weight  34 ′ is set larger than that of the weight  34 . In a case where the wheels slip on the sand ground, a tire chain may be attached on the wheels. 
     Referring to  FIGS. 2 and 3 , a tow portion  37  for use in towing the first beach cleaner  20  by the vehicle  1  is disposed on the front side of each of fourth ones of the longitudinal members  21  of the frame  22  as counted from left and right. Each tow portion  37  is a thick plate-like member extending to perpendicularly intersect the left-right direction, and has a plurality (e.g., three) of connecting holes  37   a  that are arranged in a line along an inclination of the front end portion of the longitudinal member  21 . A first one of two opposite ends of a tow rod  38  is connected to the trailer hitch  11  of the vehicle  1  and a second one of the two opposite ends of the tow rod  38  is engaged with one of the connecting holes  37   a , so that the first beach cleaner  20  is towed by the vehicle  1  through the tow rod  38  (see  FIG. 25 ). 
     By the selection of the one connecting hole  37   a  with which the second end of the tow rod  38  is engaged, the tow position can be set at the most suitable one that corresponds to the amount of sinking of the first beach cleaner  20  into the sand and other conditions. Referring further to  FIG. 14 , the tow rod  38  has the first end connected to the trailer hitch  11  and extends therefrom toward the left and right tow portions  37  into a V- or Y-like shape in top view. At the first end of the tow rod  38 , there is disposed the hitch coupler  17   a  to engage the trailer hitch  11 . 
     From each of a left and a right end of the frame  22 , a lift arm  39  protrudes outward, i.e., leftward and rightward, respectively. For instance, each lift arm  39  is a frame-like member that is rectangular in top view and substantially horizontal at its middle portion in the left-right direction with an inner portion and an outer portion thereof in the left-right direction being respectively bent obliquely downward toward the inside and outside. The dimension between outer lateral ends of the left and right lift arms  39  is larger than the dimension of the left and right side structures  41  of the litter collecting station  40  in the same direction. When the first beach cleaner  20  towed by the vehicle  1  enters a space between the left and right side structures  41 , the left and right lift arms  39  get upon the left and right side structures  41  to lift the first beach cleaner  20  by a predetermined amount. The distance between the left and right side structures  41  is larger than the transverse dimension of the vehicle  1 , and thus the vehicle  1  can travel through the space between the left and right side structures  41 . 
     As  FIGS. 13 and 14  show, when the first beach cleaner  20  is lifted at the litter collecting station  40  as described above, the sand pins  23  separate from the upper surface of the sand ground by a sufficient distance and the litter raked by the sand pins  23  fall onto the sand ground so that the litter can be gathered to be collected. 
     The litter collecting station  40  is formed by integrally connecting the left and right side structures  41  by means of a pair of connecting members  42 , i.e., a front connecting member and a rear connecting member, and may be symmetric in both of the front-rear and left-right directions, for instance. 
     Each of the left and right side structures  41  is constructed such that a guide member  44 , which may be provided by a circular steel tube and is gently angled at two points to be substantially symmetric in the front-rear direction in side view, is disposed on a bar-like ground-contact member  43 , which may be provided by a circular steel tube and extends in the front-rear direction, and front end portions and rear end portions of these members  43 ,  44  are respectively integrally connected. 
     A foot member  45  is detachably attached to each of a front end and a rear end of each of the left and right ground-contact members  43 . In top view, the foot member  45  attached to the front end is bent outward toward the front side, and the foot member  45  attached to the rear end is bent outward toward the rear side. The foot members  45  and the ground-contact members  43  together contact the sand ground, thereby increasing the contact area of the litter collecting station  40 . Hence, the litter collecting station  40  can be stably installed. 
     Referring further to  FIG. 15 , the connecting members  42  may be provided by circular steel tubes extending in the left-right direction, for instance. The connecting members  42  integrally connect the left and right side structures  41  such that end portions of the connecting members  42  are detachably inserted into respective connecting pipes  46  disposed under front and rear portions of the ground-contact members  43 . That is, the litter collecting station  40  is dividable into a plurality of parts (namely, the left and right side structures  41  and the front and rear connecting members  42 ) due to its relatively large size. 
     The connecting pipes  46  at the front and rear portions of the ground-contact members  43  are provided by relatively short circular steel tubes extending in the left-right direction. Each connecting pipe  46  is integrally combined with the ground-contact member  43  with an upper circumferential portion of the connecting pipe  46  fitted on a cutout on the under side of the ground-contact member  43 . That is, the connecting pipes  46  protrude downward from under surfaces of the ground-contact members  43 , so that when the litter collecting station  40  is installed on the sand ground, the connecting pipes  46  slightly sink into the sand to inhibit the litter collecting station  40  from moving. 
     In the assembled state where the end portion of each connecting member  42  is inserted in the connecting pipe  46  by a predetermined amount (for instance, an outer side end of the connecting pipe  46  and that of the corresponding connecting member  42  match), a vertical through-hole  42   a  formed in the connecting pin  42  and a vertical through-hole  46   a  formed in the connecting pipe  46  align, at a position on the outside of left or right of the ground-contact member  43 , for instance, and a prescribed engaging pin  47  is inserted through the vertical through-holes  42   a ,  46   a , thereby connecting the connecting member  42  and the ground-contact member  43  such that the members  42 ,  43  can not be separated from each other when assembled as described above. 
     The engaging pin  47  inserted through the connecting member  42  and the connecting pipe  46  is further inserted into the sand by a predetermined amount. That is, the engaging pin  47  restricts the litter collecting station  40  from moving from the predetermined position while the litter collecting station  40  is in the installed state. By removing the engaging pin  47  and pulling the connecting member  42  from the connecting pipe  46 , the litter collecting station  40  can be divided into the left and right side structures  41  and the front and rear connecting members  42 . 
     As  FIGS. 16 and 17  show, the second beach cleaner  50  includes a frame  53  mainly composed of a plurality (e.g., three) of longitudinal members  51  each extending along the traveling direction of the vehicle and front and rear transverse members  52   a ,  52   b  each extending in a transverse direction (left-right direction) to substantially perpendicular intersect the longitudinal members  51 . The second beach cleaner  50  further includes keel members  54  and scraper  55  that are disposed in a front portion of the frame  53  and will be described later, and a mesh member  56  (described later) disposed in a rear portion of the frame  53 . The second beach cleaner  50  is also symmetric in the left-right direction. 
     For instance, the longitudinal members  51  may be provided by circular steel tubes disposed along the front-rear direction and each being gently bent into a crank-like shape in side view at its middle portion in the front-rear direction, so that a rear portion of each longitudinal member  51  is located slightly above a front portion thereof. In the front portion of the longitudinal member  51 , a middle portion in the front-rear direction is gently bent so that a front half of the front portion is slightly inclined upward. Hereinafter, the front half of the front portion of the longitudinal member  51  will be referred to as “front inclined portion  57 ”. On the other hand, a rear end portion of the longitudinal member  51  is bent upward. The longitudinal members  51  may be provided by rectangular steel tubes. 
     A plurality of the longitudinal members  51  are arranged in the left-right direction to entirely overlap one another in side view. Front ends of the longitudinal members  51  are abutted and joined, from the rear lower side, to a front transverse member  52   a  extending along the left-right direction, which may be a rectangular steel tube. Rear ends of the longitudinal members  51  are abutted and joined, from the lower side, to a rear transverse member  52   b  extending along the left-right direction, which may be a circular steel tube. The frame  53  mainly composed of the longitudinal members  51  and the transverse members  52   a ,  52   b  is substantially foursquare in top view. The transverse dimension of the frame  53  is made substantially the same as that of the frame  22  of the first beach cleaner  20 . 
     Between one in the middle of the left-right direction arrangement of the longitudinal members  51  and each of a leftmost and a rightmost one of the longitudinal members  51 , there are arranged a plurality (e.g., three) of scraper frames  58  in the left-right direction. The scraper frames  58  are inclined to overlap the front inclined portions  57  in side view. The scraper frames  58  are formed of circular steel tubes of the same diameter as the longitudinal members  51 , but may be formed of rectangular steel tubes instead. Front ends of the scraper frames  58  are abutted and joined, from the rear side, to the front transverse member  52   a , and rear ends of the scraper frames  58  are free ends not jointed to any members. The scraper frames  58  and the longitudinal member  51  at the middle in the left-right direction are arranged at almost regular intervals, but a leftmost and a right most one of the scraper frames  58  are respectively spaced from the leftmost and the rightmost longitudinal members  51  by an interval narrower than the intervals at the other positions. 
     To the front inclined portions  57  of the longitudinal members  51  and the scraper frames  58  are attached keel members  54  and a scraper  55  that cooperate to function as a churn-up portion which churns up sand and relatively small-sized litter (e.g., beverage containers, waste paper, and cigarette butts) while the second beach cleaner  50  is traveling by being towed. 
     Referring further to  FIGS. 19 and 20 , the keel members  54  are detachably attached to rear portions of the front inclined portions  57  of the longitudinal members  51 , and rear portions of the scraper frames  58 . Each of the keel members  54  includes a plate-like member  61  curved to fit a lower outer surface of the front inclined portion  57  or of the scraper frame  58 , a U-shaped pin  62  open upward in side view and having two arms that extend through the plate-like member  61 , and a keel main body  63  formed of a plate-like member extending downward from a lower end of the plate-like member  61  to substantially perpendicularly intersect the left-right direction. 
     An upper portion of each of the two arms of the U-shaped pin  62  is formed as an externally threaded portion  62   a . With the two externally threaded portions  62   a  extending from the under side of the front inclined portion  57  or the scraper frame  58  therethrough to protrude to the upper side thereof, the plate-like member  61  contacts an under surface of the front inclined portion  57  or of the scraper frame  58 , and cap nuts  64  are threadably mounted on the respective externally threaded portions  62   a  and tightened, thereby fixing the keel member  54  to the front inclined portion  57  or the scraper frame  58 . At positions where the two arms of the U-shaped pin  62  extend through the front inclined portion  57  or scraper frame  58 , there are inserted and fixed cylindrical collars  65 . 
     At a rear end portion of each keel member  54  (or of each keel main body  63 ), a plurality of scraper support holes  66  are formed, and the scraper  55  is inserted and supported to each of the scraper support holes  66 . For instance, the scraper  55  is a bar-like member extending along the left-right direction and circular in cross section, and extends across the keel members  54  by being inserted through and supported by one of the scraper support holes  66  arranged in the vertical direction. The scraper  55  is selectively supportable depending on the conditions of the sandy beach and litter, and a plurality of scrapers  55  are supportable. At each of two opposite ends of the scraper  55 , there is provided a stopper for preventing falling off of the scraper  55  from the keel members  54 . For instance, the stopper may be a predetermined engaging pin inserted. The cross-sectional shape of the scraper  55  may not be limited to a circular shape but may be otherwise. For instance, the scraper  55  may have an upper surface inclined downward toward the front side to be semi-circular in cross section. A single scraper  55  may be used, or alternatively three or more scrapers  55  may be used, and the scrapers  55  may not be arranged in the vertical direction but in the left-right direction or obliquely. 
     The keel members  54  and the scraper  55  are disposed to sink into the sand by a suitable amount. With the keel members  54  and the scraper  55  in such a sunk condition, the second beach cleaner  50  travels so that the keel members  54  push through the sand and litter, and the scraper  55  churns up the sand and litter. The churned up sand and litter are deposited in the mesh member  56  in the rear portion of the frame  53 . 
     Referring to  FIGS. 16 and 17 , a tow portion  67  for use in towing the second beach cleaner  50  by the vehicle  1  is disposed on the front side of each of the second leftmost one and the second rightmost one of the scraper frames  58  as counted from left and right of the frame  53 , respectively, for instance. The tow portion  67  is formed of a thick plate-like member extending to perpendicularly intersect the left-right direction, and has a plurality (e.g., four) of connecting holes  67   a  arranged in the vertical direction. The second end of the tow rod  38  the other end of which is connected to the trailer hitch  11  is engaged with one of the connecting holes  67   a , so that the second beach cleaner  50  is towed by the vehicle  1  through the tow rod  38  (see  FIG. 26 ). 
     By the selection of the one connecting hole  67   a  with which the second end of the tow rod  38  is engaged, the tow position can be set at the most suitable one that corresponds to the road clearance of the second beach cleaner  50  and other conditions. The transverse distance between the left and right tow portions  67  is almost the same as that of the left and right tow portions  37 . 
     For instance, on the front side of each of the leftmost and rightmost scraper frames  58  of the frame  53 , a front ski support pipe  72  for supporting a front ski leg  71  is disposed. The front ski support pipe  72  is provided by a member, which may be a rectangular steel tube, for instance, and vertically extends through the front transverse member  52   a . The front ski support pipe  72  can support a leg member  73  of the front ski leg  71  as inserted in the front ski support pipe  72 . The leg member  73  is provided by a rectangular steel tube. The front ski leg  71  functions to set the road clearance (the height from the upper surface of the sand ground) of a front portion of the second beach cleaner  50  at a predetermined value, and enhance the slidability of the second beach cleaner  50  on the sand ground. The front ski leg  71  is constructed such that the leg member  73  stands on a front ski plate  74  having a predetermined width and a upward curved front portion. 
     The front ski support pipe  72  has a transverse through-hole  72   a , and the leg member  73  has a plurality (e.g., four) of transverse through-holes  73   a  vertically arranged to correspond to the transverse through-hole  72   a . By aligning one of the transverse through-holes  73   a  with the transverse through-hole  72   a  of the ski support pipe and inserting a predetermined engaging pin or others through the aligned holes  73   a ,  72   a , the height of the front portion of the frame  53  relative to the front ski leg  71  is determined, thereby setting the road clearance of the front portion of the second beach cleaner  50  at the predetermined value. That is, by selecting the one of the transverse through-holes  73   a  of the leg member  73  into which the engaging pin or others is inserted, the road clearance of the front portion of the second beach cleaner  50  is adjustable, thereby enabling adjustment of the amount of sinking of the keel members  54  and the scraper  55  into the sand. 
     From a rear side of the rear transverse member  52   b  and at each of two lateral sides, an extension frame  75 , which may be provided by a rectangular steel tube, extends rearward. At rear end portion of the extension frame  75 , a rear ski support pipe  77  for supporting a rear ski leg  76  is disposed. The rear ski support pipe  77  vertically extends through the extension frame  75  and may be provided by a rectangular steel tube, for instance. The rear ski support pipe  77  can support a leg member  78  of the rear ski leg  76  as inserted in the rear ski support pipe  77 . The leg member  78  may be provided by a rectangular steel tube. The rear ski leg  76  has the same structure and function as those of the front ski leg  71 , and is constructed such that the leg member  78  stands on a rear ski plate  79 . 
     The rear ski support pipe  77  has a single transverse through-hole  77   a , and a plurality (e.g., four) of transverse through-holes  78   a  vertically arranged are formed in the leg member  78  to correspond to the transverse through-hole  77   a . By aligning one of the transverse through-holes  78   a  with the transverse through-hole  77   a  of the ski support pipe and inserting a predetermined engaging pin or others through the aligned holes  78   a ,  77   a , the height of the rear portion of the frame  53  relative to the rear ski leg  76  is determined, thereby setting the road clearance of the rear portion of the second beach cleaner  50  at the predetermined value (that is, the rear portion of the second beach cleaner  50  is adjustable). The transverse dimension between the outer ends of the front ski plates  74  of the left and right front ski legs  71  is substantially the same as the transverse dimension of the frame  53 , and the transverse dimension between the outer ends of the rear ski plates  79  of the left and right rear ski legs  76  is narrower than the transverse dimension of the frame  53 . 
     At the front and rear portions of the frame  53  and on the left and right outer sides thereof, there are disposed front and rear lift arms  81   a ,  81   b  each of which extends from the outer end leftward and rightward. Each lift arm  81   a ,  81   b  is a frame-like member having a rectangular shape long in the transverse direction in top view, for instance. A middle portion of each of the lift arm  81   a ,  81   b  in the left-right direction is substantially horizontal, with an inner portion and an outer portion thereof in the left-right direction being respectively bent obliquely downward toward the inside and the outside. The dimension between outer lateral ends of the left and right lift arms  81   a ,  81   b  is larger than the dimension of the left and right side structures  41  of the litter collecting station  40  in the same direction (in other words, substantially the same as the transverse dimension between the outer lateral ends of the left and right lift arms  39  of the first beach cleaner  20 ). When the second beach cleaner  50  enters a space between the left and right side structures  41 , the left and right lift arms  81   a ,  81   b  get upon the left and right side structures  41  to lift the second beach cleaner  50  by a predetermined amount. 
     When the second beach cleaner  50  is lifted at the litter collecting station  40  as described above, the mesh member  56  at the rear portion of the frame  53  lifts to a predetermined level, and it becomes easy to collect the litter deposited in the mesh member  56  by pivoting the mesh member  56  around a hinge  82  disposed at the left side of the mesh member  56  (see  FIG. 18 ). However, the collection of litter is possible even while the second beach cleaner  50  is in contact with the ground and not lifted. 
     Referring further to  FIGS. 21 ,  22 , on the rear lift arm  81   b  at the left side of the frame  53 , there is disposed a rear hinge bracket  83  constituting a part of the hinge  82  pivotally supporting a left-side portion of the mesh member  56 . The rear hinge bracket  83  extends in the front-rear direction along the proximal side of the rear lift arm  81   b , and has, at its front and rear ends, front and rear walls  84  standing upward. At an end portion of each of the front and rear walls  84 , there is formed a longitudinal through-hole  84   a  for a hinge shaft  82   a . Between the front and rear walls  84 , a rear hinge pipe  85  disposed at the left side of the mesh member  56  to correspond to the rear hinge bracket  83 , so that the rear hinge pipe  85  is pivotally supported by the rear hinge bracket  83  via the hinge shaft  82   a  extending in the left-rear direction. 
     On the slightly front side of the rear lift arm  81   b , a support arm  86  as a frame-like member having a transverse dimension smaller than that of the lift arm  81   b . The support arm  86  supports a front hinge bracket  87  constructed similarly to the rear hinge bracket  83 . In each of front and rear walls  88  of the front hinge bracket  87 , a longitudinal through-hole  88   a  for a hinge shaft  82   a  is formed. Between the front and rear walls  88 , a front hinge pipe  89  is disposed at the left side of the mesh member  56  to correspond to the front hinge bracket  87 . The front hinge pipe  89  is pivotably supported by the front hinge bracket  87  via the hinge shaft  82   a  extending in the front-rear direction. The hinge pipes  85 ,  89  and hinge shafts  82   a  are coaxial with one another. 
     As shown in  FIGS. 16 and 17 , the mesh member  56  has a box-like shape open at the front and upper sides. For instance, the mesh member  56  is constructed such that a metallic mesh with a predetermined mesh size is attached to a frame mainly composed of steel tubes. The mesh member  56  is disposed from a position slightly forward side of the longitudinal center of the frame  53  to a position near a rear end of the frame  53 , and the transverse dimension of the mesh member  56  is substantially the same as that of the frame  53 . The position of the front end of the mesh member  56  is spaced toward the rear side from the proximity of the rear end portions of the keel members  54 , i.e., the proximity of the scraper  55 , by about 100-300 mm, so as to well catch the sand and litter churned up by the keel members  54  and the scraper  55 . More preferably, the position of the front end of the mesh member  56  is spaced toward the rear side from the proximity of the rear ends of the keel members  54  by about 250 mm. 
     Referring further to  FIG. 18 , the mesh member  56  has a bottom wall  92  having a rectangular shape long in the transverse direction in top view, a rear wall  93  standing substantially upright from a rear end of the bottom wall  92 , and left and right side walls  94  each standing slightly obliquely from opposite lateral ends of the bottom wall  92  to incline outward, i.e., to the left and right, toward the upper side. To enable to deposit the litter churned up by the keel members  54  and the scraper  55  on the bottom wall  92 , the rear wall  93  and the left and right side walls  94  cooperate to form an encircling member  91  that encircles the circumference of the bottom wall  92  except a part at the front side so that the encircling member  91  is open at the front side. 
     A front portion of the bottom wall  92  is slightly inclined frontward to form an inclined portion  92   a . The other part of the bottom wall  92  on the rear side of the inclined portion  92   a  forms a horizontal portion that extends substantially horizontally. The horizontal portion is sectioned into a front horizontal portion  92   b  and a rear horizontal portion  92   c , by a border in the form of a transverse member extending in the left-right direction. 
     A metallic mesh with a mesh size of 25 mm is attached to the inclined portion  92   a  of the bottom wall  92 , a metallic mesh of a mesh size of 12 mm is attached to the front horizontal portion  92   b , and a metallic mesh with a mesh size of 8 mm is attached to the rear horizontal portion  92   c.    
     By setting the mesh sizes of the metallic meshes constituting the bottom wall  92  to become rougher from rear to front, a part of the sand and others churned up by the keel members  54  and scraper  55 , which are relatively heavy due to a large amount of moisture retained thereby, does not reach the rear side of the bottom wall  92 , but is well sieved off to fall to the ground through the roughest mesh at the inclined portion  92   a  at the front side of the bottom wall  92 , without causing clogging or other problems. On the other hand, the remaining part of the churned up sand and others which are relatively light due to their high dryness reach the horizontal portion at the rear side of the bottom wall  92  along with the litter, and are sieved off to fall to the ground through the second roughest and finest meshes attached there while the litter does not fall through the meshes but is excellently caught thereat. The meshes are suitably replaceable among those with mesh sizes of 8, 10, 12 and 25 mm, or within a range like this. 
     Each of the side walls  94  of the mesh member  56  has a side-wall main body  94   a  having a rectangular shape long in the front-rear direction in side view and disposed on the upper side of one of the lateral ends of the bottom wall  92 , and a rear protruding portion  94   b  having a trapezoidal shape in side view and disposed on the upper side of a rear portion of the side-wall main body  94   a . Rear ends of the side-wall main body  94   a  and the rear protruding portion  94   b  are aligned into a straight line extending substantially upright in side view. The rear wall  93  of the mesh member  56  is disposed such that two lateral ends of the rear wall  93  agree with these rear ends. An upper end of each side wall  94  and that of the rear wall  93  are located substantially at the same height level. 
     Front and rear hinge plates  95   a ,  95   b  are disposed on the left side wall  94  at a front position and a rear position therein respectively, such that the front and rear hinge plates  95   a ,  95   b  extend across a middle frame member and a lower frame member of the side-wall main body  94   a  of the left side wall  94 . The hinge plates  95   a ,  95   b  are plate-like members each of which is substantially foursquare in side view and a part of which is suitably cut out to leave an outer rim and a part along diagonal lines. Front and rear end portions of the hinge plates  95   a ,  95   b  are bent inward in the left-right direction to form a reinforcing flange. On outer side surfaces of the hinge plates  95   a ,  95   b , there are integrally connected the front and rear hinge pipes  89 ,  85 , respectively. 
     On the upper side of a front portion of each of the left and right side walls  94  (and above the front hinge plate  95   a  with respect to the left side wall  94 ), a handle  96   a  is disposed to protrude upward from the upper end of the side wall  94 . The handle  96   a  is U-shaped open downward in side view, and disposed such that an upper straight segment thereof extends along the front-rear direction. The handle  96   a  is inclined to be located on the outer side of the corresponding side wall  94  by a slight amount. Two handles  96   b  are disposed at the upper side of the rear wall  93  such that the handles  96   b  protrude upward from an upper end of the rear wall  93  at a left-side and a right-side position, respectively. Each of the handles  96   b  is U-shaped open downward in rear view, and disposed substantially upright such that an upper segment thereof extends in the left-right direction and substantially in the same plane as the rear wall  93 . 
     The left-side portion of the mesh member  56  is pivotably connected to the left side of the frame  53  via the hinge  82  to be supported thereby, as described above. When the mesh member  56  is brought into an upright position where the bottom wall  92  thereof is substantially upright, by moving a right side portion of the mesh member  56  upward to pivot the mesh member  56  via the hinge  82 , the litter deposited in the mesh member  56  falls onto the left side wall  94  so that the litter is moved along the left side wall  94  to be discharged out of the mesh member  56 . 
     Since the handles  96   a ,  96   b  are disposed at the respective positions (that should include at least the position opposite to the hinge  82 ) on the encircling member  91  of the mesh member  56 , collection of litter by pivoting the mesh member  56  is made easy. By disposing the hinge  82  at one of the shorter sides (the left side) of the transversely elongate mesh member  56 , the dimension from the pivot axis around which the mesh member  56  is pivoted to stand upright, to the operated portion (handle at the right side) is made relatively large, so as to facilitate the operation to pivot the mesh member  56 . 
     The left side wall  94  of the mesh member  56  (in other words, the wall on the side of the hinge  82  of the encircling member  91 ) is provided with a board to obtain a good result of the discharge of litter. The upper end of the left side wall  94  of the mesh member  56  projects leftward from the outer side of the litter collecting station  40  when the mesh member  56  is made to stand upright (see  FIG. 18 ). Hence, where a litter collecting container is placed adjacent to the left side of the litter collecting station  40 , the left side wall  94  is inclined to be a slope enabling direct input of the deposited litter from the mesh member  56  into the container. The right side wall  94  and the rear wall  93  of the mesh member  56  are constructed to prevent falling off of the litter input into the mesh member  56 , and may be formed as a mesh portion where a metallic mesh with a relatively large mesh size is attached, for instance. 
     On the leftmost and rightmost longitudinal members  51  of the frame  53 , there are disposed left and right front-end stoppers  97   a  and left and right rear-end stoppers  97   b  that determine the positions of left and right front ends and left and right rear ends of the mesh member  56 . Each stopper  97   a ,  97   b  has a position regulating surface that is substantially vertical and a pivoting guide surface. The position regulating surface is to contact the front or rear end of the mesh member  56 , and the pivoting guide surface extends continuously from and above the position regulating surface and is inclined with respect thereto. For instance, the stoppers  97   a ,  97   b  are detachably attached to the longitudinal member  51  using a bolt or others. 
     The position regulating surfaces of the left and right front-end stoppers  97   a  are contacted by the left and right front ends of the mesh member  56  in use (i.e., in the state where the bottom wall  92  is held substantially horizontal and in contact with the frame  53 ), and the position regulating surfaces of the left and right rear-end stoppers  97   b  are contacted by the left and right rear ends of the mesh member  56  in use, whereby the mesh member  56  is positioned relative to the frame in the front-rear direction. When the mesh member  56  is pivoted to return its position from the upright position to the position for use, the left and right front ends and the left and right rear ends thereof are guided by the guide surfaces of the stoppers  97   a ,  97   b , thereby smoothly returning the mesh member  56  to its predetermined position on the frame  53 . 
     As shown in  FIG. 23 , the positions on the longitudinal members  51  where the stoppers  97   a ,  97   b  are attached may be shiftable in the front-rear direction. In a case where such a structure is employed, the mesh member  56  also becomes shiftable in the front-rear direction according to the shift of the stoppers  97   a ,  97   b , by means of setting the lengths of the front and rear hinge pipes  85 ,  89  at the left side of the mesh member  56  smaller than the distances between the front and rear walls  84 ,  88  of the front and rear hinge brackets  83 ,  87 , respectively, or by other means. The thus making the front end position of the mesh member  56  easily changeable depending on the state of the sand ground enhances the capability of the second beach cleaner  50  to capture litter. 
     There will be roughly described a procedure of cleaning a sandy beach using the beach cleaners  20 ,  50 . 
     First, the litter collecting station  40  is carried by being mounted in the trailer  13  as shown in  FIG. 1  and installed at a predetermined position on the sandy beach. Although  FIG. 1  shows an example where the litter collecting station  40  as assembled is mountable on the trailer  13 , the litter collecting station  40  may be mounted on the trailer  13  in the above-described disassembled state where the side structures  41  and the connecting members  42  are disconnected from each other. In this case, installation of the litter collecting station  40  including loading and unloading thereof onto and from the trailer  13  is easier. It is noted that in  FIG. 1  only the foot members  45  are removed from the litter collecting station  40 . 
     Next, the firmness of the ground of the sandy beach is measured to be used as a criterion for determination of the number of the sand pins  23  of the first beach cleaner  20  and the amount of sinking of the keel members  54  and scraper  55  of the second beach cleaner  50  into sand ground. For instance, this measurement may be conducted such that a steel picket of a predetermined size is made to free-fall from a predetermined height level onto the sand ground for a plurality of times, and the firmness of the sand ground is evaluated into three ranks (soft, medium, and firm) based on an average value of the results obtained by the free-fallings. Depending on the measured firmness of the sand ground and the scattering state of the litter and other conditions, the number of the sand pins  23 , the weight of the weight  34 , the level at which the ski legs are attached, the connecting position of the tow rod  38  relative to the tow portions  37 ,  67 , and others are determined. 
     Then, the first beach cleaner  20  is taken down from the trailer  13 , and various settings are made based on the result of the measurement of the firmness of the sand ground. Thereafter, the first beach cleaner  20  is towered by the vehicle  1  to travel on the sand ground at a constant speed. As shown in  FIG. 24 , the vehicle  1  and first beach cleaner  20  is moved to travel along a circling path drawn within a predetermined range on the sand ground and substantially formed of a plurality of squares whose positions are gradually shifted, so as to evenly clean the predetermined range with assuredness. Since the first beach cleaner  20  picks up litter of relatively large size on the sandy ground by having the sand pins  23  biting into the sand ground, the travel resistance thereof is relatively high. Hence, the travel speed thereof is set at a value as low as about 5-10 km/h. 
     When litter is deposited under the frame  22  of the first beach cleaner  20  in a predetermined amount as a result of traveling of the first beach cleaner  20  over the sandy beach in the way as described above, the first beach cleaner  20  is returned to the litter collecting station  40  so that collection of the deposited litter is performed. The deposited litter is collected such that when the first beach cleaner  20  enters the space between the left and right side structures  41  after the vehicle  1  has passed through the left and right side structures  41  of the litter collecting station  40 , the left and right lift arms  39  thereof get upon the left and right side structures  41  to lift the first beach cleaner  20  by the predetermined amount (see  FIG. 13 ). In this state, the vehicle  1  and first beach cleaner  20  are stopped, and then the litter having been let to fall onto the sand ground is collected. Then, the vehicle  1  and first beach cleaner  20  are again made to travel to repeat the above-described litter collection. 
     When the cleaning using the first beach cleaner  20  over the predetermined range is done, the second beach cleaner  50  is made to travel over the same range by towing thereof to pick up litter of relatively small size on the sandy beach. By using the second beach cleaner  50  after use of the first beach cleaner  20 , damage of the keel members  54 , scraper  55 , mesh member  56 , and others that deal with small-sized litter is reduced. The path along which the second beach cleaner  50  travels is the same as that of the first beach cleaner  20 . When the second beach cleaner  20  travels, the sand ground has been turned up by the operation of the first beach cleaner  20  and soft, and the keel members  54  and the scraper  55  should churn up sand and litter. Hence, the travel speed of the second beach cleaner  20  is set at a value slighter higher than that of the first beach cleaner  20 , i.e., about 15-25 km/h. 
     By the second beach cleaner  50  traveling over the sandy beach, litter of relatively small size is churned up along with sand by the keel members  54  and the scraper  55 , and the churned up litter and sand are deposited in the mesh member  56  at the rear portion of the frame  53 . Since it is set such that the mesh size of the meshes at the bottom wall  92  of the mesh member  56  decreases from front to rear, the deposited litter does not easily fall and clogging of the meshes is inhibited. 
     When the predetermined amount of litter has been deposited in the mesh member  56  as a result of the traveling of the second beach cleaner  50  over the sandy beach in the way as described above, the second beach cleaner  50  returns to the litter collecting station  40  and collection of the deposited litter is performed. The deposited litter is collected such that when the second beach cleaner  50  enters the space between the left and right side structures  41  of the litter collecting station  40  after the vehicle  1  has passed through the left and right side structures  41 , the left and right lift arms  81   a ,  81   b  at the front and rear sides thereof get upon the left and right side structures  41  to lift the second beach cleaner  50  by the predetermined amount. In this state, the vehicle  1  and second beach cleaner  50  are stopped, and the mesh member  56  is pivoted and the deposited litter is collected. Thereafter, the vehicle  1  and the second beach cleaner  50  are again made to travel to repeat the collection of litter as described above. 
     As has been illustrated above, the second beach cleaner  50  according to the embodiment includes: the frame  53  including the plurality of longitudinal members  51  each extending along the traveling direction and the plurality of transverse members  52   a  and  52   b  each extending in the transverse direction such that the transverse members  52   a ,  52   b  extend substantially perpendicularly to the longitudinal members  51 ; the keel members  54  and the scraper  55  disposed in the front portion of the frame  53 ; the mesh member  56  disposed in the rear portion of the frame  53 ; and the tow portion  67  disposed at the front end portion of the frame  53 , the churn-up portion churning up litter scattered on the sand ground, along with sand, while the second beach cleaner  50  is traveling on the surface of the sand ground by being towed by the towing vehicle  1 , and the churned up litter being deposited in the mesh member  56 , wherein the mesh member  56  has the encircling member  91  open at least at a side, and the mesh of the mesh member  56  is relatively rough at the front portion thereof in the traveling direction and finer at the rear portion thereof in the traveling direction than that of at least the front portion. 
     According to this arrangement, relatively heavy damp sand is well sieved off to fall through the relatively rough mesh at the front portion of the mesh member  56  in the traveling direction. On the other hand, relatively light dry sand reaches the rear portion of the mesh member  56  in the traveling direction along with litter of relatively small size, and sieved off to fall through the relatively fine mesh while the litter does not tend to fall therethrough but is caught excellently. That is, irrespective of the conditions of the sand and litter, the sand reaching the mesh member  56  is allowed to easily fall while the litter is inhibited from falling, thereby enhancing the capability of the second beach cleaner  50  to collect litter. 
     In the second beach cleaner  50 , the mesh member  56  is disposed to be shiftable in position in the front-rear direction and relative to the frame  53 . Thus, the position of the mesh member  56  is shiftable in the front-rear direction depending on the state of scraping up of sand and litter, thereby allowing the sand to fall further easily and inhibiting the litter from falling more strictly. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.