Abstract:
A garden screening device for sifting and separating gravel, rocks, stones, and other debris from useful and valuable soil includes a screening drum mounted on a rotatable base supported on a carriage assembly, the screening drum and base interconnected to a drive motor and pulley for rotating the drum so that useful and valuable soil can be separated and sifted through the screen mesh of the drum by rotation of the drum and directed to the ground by a slide while the unwanted debris is retained in the drum for removal by tilting the screening drum in the direction opposite of the screening drum&#39;s operational sifting and separating disposition.

Description:
FIELD OF THE INVENTION 
   The present invention pertains to devices that screen and separate usable and valuable material from unwanted and unusable material, and more particularly pertains to a device for separating and screening unusable soil, rocks, gravel, stones, and like debris from the usable and valuable soil. 
   BACKGROUND OF THE INVENTION 
   The separating, shredding, mixing, pulverizing, sifting and sorting of material is a common and widespread agricultural and industrial application and practice. Such applications are to be found in the steel, glass, chemical, pharmaceutical, and food processing industries where liquid, semi-liquid, and liquid and solid product must be mixed and sifted, separated and sorted for transformation into a usable and valuable end product or commodity. 
   However, the above processes are applicable not only for large-scale industries but also for small scale concerns and businesses as well as individuals involved in activities such as building, remodeling, renovating, landscaping, gardening and general outside work. Thus, in situations such as landscaping, preparing a garden or starting a lawn as part of a new housing project, a primary task is soil preparation. The soil must be screened and sifted in order to separate and remove the usable and valuable soil—topsoil or loam, for example—from the unwanted and unusable soil and other debris found therein. The other debris may include such items as stones, rocks, gravel, roots, branches, and bulk waste, trash, and rubbish that has not been broken down or decomposed. 
   Some common ways of sifting and sorting through soil material include simply walking the parcel and manually removing the clumps of debris, using a shovel or other implement to manually sift and sort through the soil, and placing a flat mesh screen on a wheelbarrow and then placing loads of soil on the screen for separating the unusable and unwanted debris from the valuable soil. These methods are time consuming and labor intensive, and produce uneven results as far as the quality of the soil screened and sorted. 
   The prior art discloses a wide variety of devices for separating, sorting, spreading, shredding and mixing material to obtain a desirable end product. 
   For example, the Raney et al. patent (U.S. Pat. No. 3,025,067) discloses a flail beater unit attached to the rear of a manure spreader unit. Manure is brought to the flail beater unit by a conveyor whereupon the manure is beaten and spread by individual flails rotating on a center shaft. 
   The Skretting patent (U.S. Pat. No. 4,303,508) discloses a screening device wherein an externally slotted screen drum is enclosed within a housing so that primarily cellulose-type material passes through the slots when moving from the inlet to the outlet. 
   The Svehaug patent (U.S. Pat. No. 4,426,289) discloses a liquid-solid screen separator that includes a slurry screening assembly mounted within a rotatable housing for screening the slurry, a compression roller freely rotatable therein for further compressing the material, and an augur for moving the material through the separator. 
   The Palus et al. patent (U.S. Pat. No. 4,767,218) discloses a vat for mixing delicate material and which includes a carriage assembly linearly movable on a beam member, and pendent from the carriage assembly are mixing paddles having blades that can be selectively angled for achieving maximum mixing results. 
   The Thompson patent (U.S. Pat. No. 4,885,012) discloses a conveyance apparatus for moving granular matter, and includes a container having inlet and outlet conduit, a rotary screen assembly within the housing, and a rotary valve for continuously moving the material. 
   The Lundell patent (U.S. Pat. No. 4,960,247) discloses a compost shredder wherein compost is fed into the hopper for shredding by hammers pivotally mounted to a shaft that extends through a drum that receives the compost from the hopper. 
   The Byers patent (U.S. Pat. No. 5,118,414) discloses a screening device for removing unwanted material from water, and includes a plurality of upright annular discs having peripheral teeth for catching and directing unwanted material to a collection zone. 
   Nonetheless, despite the ingenuity of the above devices, there remains a need for a simple, portable screening device for small business concerns, homeowners and individuals for quickly and efficiently screening and sorting unwanted material from usable soil. 
   SUMMARY OF THE INVENTION 
   The present invention comprehends a portable garden screening device for mixing, sifting, sorting, and separating rocks, gravel, pebbles, stones, twigs, leaves, roots and other debris from useful and valuable soil. The garden screening device can be used by both individual homeowners and professionals to improve the soil quality of their garden, yard, lawn or parcel for seeding, planting, and general health. 
   The garden screening device includes a carriage assembly composed of two opposed frameworks mounted on two wheels for portability from site to site. The opposed frameworks are interconnected by support members, and one framework includes a motor mount platform that supports a motor and a gear box arrangement. Pivotally mounted to the upper ends of both frameworks is a base, and the base is rotated by a pulley assembly driven by the motor. A screening drum is securable to the base, and rotates therewith, with the material to be mixed being placed into the drum so that the useful soil passes through the apertures of the screening drum while the unwanted and discardable debris is retained in the drum. A handle interconnected to the base allows the user to pivot the base and screening drum between an operational position and an opposite dump position whereby the unwanted material can be dumped from the drum into, for example, a wheelbarrow. 
   It is an objective of the present invention to provide a garden screening device that allows for a portable and efficient way for a homeowner to improve the soil quality of his or her property. 
   It is another objective of the present invention to provide a garden screening device that efficiently sifts, sorts, and separates gravel, stones, rocks and other debris from useful high quality loam. 
   It is yet another objective of the present invention to provide a garden screening device having interchangeable hoppers of different geometric configurations for enhancing the sifting and separating process. 
   It is still another objective of the present invention to provide a garden screening device having interchangeable hoppers each of which has a different mesh size. 
   Still another objective of the present invention to provide a garden screening device that is operable by either a gas or electric motor. 
   Still yet another objective of the present invention is to provide a garden screening device that includes a hopper having fins or vanes mounted to the interior of the hopper for improving the circulation, sifting, and separation of the material therein. 
   A still further objective of the present invention is to provide a garden screening device that can be used with both dry and wet soil. 
   These and other objects, features and advantages will become apparent to one skilled in the art upon a perusal of the following detailed description when read in conjunction with the following drawings and appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the preferred embodiment of the garden screening device of the present invention; 
       FIG. 2  is a side elevational view of the garden screening device illustrating the disposition of the device when in the screening and sifting mode; 
       FIG. 3  is a side elevational view of the garden screening device illustrating the deposition of useful, valuable soil on the ground adjacent to the garden screening device; 
       FIG. 4  is a side elevational view of the garden screening device illustrating the disposition of the device when in the dump mode or position; 
       FIG. 5  is a front elevational view of the garden screening device illustrating the addition of vanes to the interior of the screening drum; and 
       FIG. 6  is a rear elevational view of the garden screening device illustrating the upper ends of the frameworks and the pivotal mounting of the base thereto. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Illustrated in  FIGS. 1-6  is a portable garden screening device  10  for mixing, sifting, sorting and separating gravel, stones, rocks, pebbles, roots, twigs, branches and other such undesirable and unwanted soil and debris material  12  from the useful and valuable soil and loam  14 . The garden screening device  10  can be used by both professionals and individual homeowners to improve and enhance the quality of their soil for seeding, planting, gardening and landscaping. 
   As shown in  FIGS. 1-4 , the garden screening device  10  includes a carriage assembly  16  that includes opposed triangular-shaped frameworks  18  comprised of support members of any durable and weather resistant material such as angle iron members. The upright support members are joined together by cross supports. The garden screening device  10  includes at least two wheels  20  connected by an axle and mounted to the lower ends of the respective frameworks  18 . The wheels  20  provide for the portability of the garden screening device  10  so that the device  10  can be moved to different positions at one work site and to different work sites. 
   As shown in  FIGS. 1-4 , a motor mount platform  22  is secured to one of the triangular-shaped frameworks  18 , and disposed on the motor mount platform  22  is a motor drive means that includes a motor  24 , a gear box or gear case  26 , and a main drive shaft  28 . The motor  24  can be either electric powered or gasoline powered, and preferably the motor  24  should be between 1½ to 5 horsepower. The motor  24  will also include the appropriate start and stop switches or buttons. The garden screening device  10  of the present invention can also be adapted for support on four wheels, and with either the electric or gasoline motor  24 , the device  10  could become a self-propelled machine. 
   As shown in  FIGS. 1-5 , the main drive shaft  28  is engaged to a pulley assembly, and, more specifically, the main drive shaft  28  of the motor  24  is connected to a drive pulley  30 . The drive pulley  30  is interconnected to a larger driven pulley  32  by an endless belt  34 , and the larger pulley  32  is journaled to the upper end of one triangular framework through a main pulley shaft  36 . The inner end of the main pulley shaft  36  includes main pulley teeth that drivingly engage structure hereinafter further described. Illustrated in  FIG. 6  is a curvilinear cross arm  38  that extends between and is pivotally attached to the upper ends of both triangular-shaped frameworks  18 . A stud  40  projects from the midpoint of the curvilinear cross arm  38 . Journaled to the upper end of the triangular framework  18  opposite of the upper end to which the larger pulley  32  and main pulley shaft  36  is mounted is a secondary toothed shaft  42 . A handle  44  is pivotally interconnected to the secondary shaft  42  for manual pivotal movement between a use position and a dump position. Also, a dump or safety release latch  46  is mounted to the upper end of the framework  18  and is interengaged to the handle  44  to release the handle  44  for manual pivotal movement between the use or screening position and the dump position. 
   As shown in  FIGS. 1-6 , a screening drum bowl or base  48  is pivotally mounted at the upper ends of each triangular-shaped framework  18 . The bowl or base  48  is attached by the pin, bolt or stud  40  to the cross arm  38  so that the pivotal movement of the cross arm  38  results in the concomitant pivotal movement of the base  40 . The base  48  includes an inner concavity whereupon at least some of the material  12  and soil  14  temporarily resides during the mixing, sifting, separating and sorting action. The base  48  includes an inner annular lip or rim  50  and along the peripheral edge of the base  48  are base rim teeth  52  that project opposite of the rim  50 . The teeth  52  of the base  48  are drivingly engaged by the teeth of the main pulley shaft  36  and the secondary shaft  42  for rotating the base  48 . 
   As shown in  FIGS. 1-5 , the various kinds of material  12  and soil  14  to be mixed, sorted, sifted and separated by the device  10  are placed in a screening drum  54  that is removably mountable to the rim  50  of the base  48 . The screening drum  54  is a cylindrical wire screen mesh  56  having a plurality of apertures  58  with the wire screen mesh  56  in one preferred configuration being ¼ inch diameter and the aperture  58  size being a ½ square. The screening drum  54  can come in many interchangeable configurations, and other aperture  58  sizes can be ¼ inches, ¾ inches and ⅜ inches. In addition, although the preferred geometric configuration of the screening drum  54  is cylindrical as shown in  FIGS. 1-5 , the screening drum  54  can be in the form of other non-cylindrical geometric shapes such as an octagonal shape. The screening drum  54  includes an outlet end  60  for receiving the material, an interior receptacle or mixing chamber  62 , and an opposite mixing end  64  where the material  12  and soil  14  is mixed, sifted and sorted. The base  48  also serves as the floor surface for supporting the material  12  and the soil  14  while both are being mixed, sorted, separated and sifted. 
   In addition, as shown in  FIG. 5 , the interior chamber  62  of the screening drum  54  can be modified to enhance the mixing of the material  12  and soil  14  by the addition of fins or vanes  66 . The vanes  66  can be secured to either the base  48  or the screen mesh  56  and would project into the chamber  62  for enhancing the disturbance and circulation of the material  12  and soil  14  for the sifting, sorting and separating thereof. Moreover, the vanes  66  provide a shearing action on the material  12  and soil  14  thereby breaking down, for example, larger clumps of soil  14 . The configuration of the vanes  66  shown in  FIG. 5  represents one of many possible arrangements for the vanes  66 . In order to direct or guide the useful and valuable soil or loam  14  down onto the ground  68  for collection, a soil slide  70  is angularly mounted to the carriage assembly  16  and extends between and is secured to both frameworks  18 . The soil slide  70  is positioned adjacent and below the mixing end  64  of the screening drum  54  so that the valuable soil  14  falls directly on the slide  70  for conveyance to the ground  68 . 
   In operation the first step is to start the motor  24 . This engages the pulley assembly and turns the main drive shaft  28  and the main pulley shaft  36  thus causing rotation of the base  48  and the screening drum  54  mounted thereon. Soil material including the rocks, stones, gravel, limbs, twigs and other debris is shoveled into the interior chamber  62  of the screening drum  54  and into the mixing end  64  of the drum  54 . As the screening drum  54  rotates the circulation, mixing, sifting, sorting and separating of the material  12  and soil  14  occurs whereupon the valuable loam  14  will fall through the screen mesh apertures  58  and travel down the slide  70  for collection on the ground  68  while the undesirable debris accumulates in the mixing end  64  of the screening drum  54 . When a sufficient amount of unusable debris has accumulated in the screening drum  54 , the motor  24  is stopped and the safety release latch  46  is pulled. This permits the individual to pivot the handle  44  rearward thereby also pivoting or rotating rearward the cross arm  38 , the base  48 , and the screening drum  54  as a unit so that drum  54  is moved to the dump position, as shown in  FIG. 4 , for dumping the debris material  12  into a wheelbarrow or onto the ground  68 . The handle  44  is then pivoted in the opposite forward direction to the original screening position. This action locks the safety latch  46  in place preventing the inadvertent movement of the handle  44  while the screening drum  54  is in operation. The shoveling of material into the screening drum  54  and the mixing, sifting, separating and the dumping of the unwanted debris material  14  can be repeated until the desired area, garden, lot, or yard is screened. Using interchangeable drums having screen mesh apertures of varying sizes, the stones, gravel, pebbles and other debris can be re-screened as desired for further uses. 
   It should be noted that various other modifications of the invention will become apparent to those skilled in the art and the invention is accordingly not limited to the preferred embodiment only but includes those modifications and variations within the scope and spirit of the appended claims.