Abstract:
An integrated terminal deck and spout assembly for a vibrating separator and a method of fabricating a terminal deck constructed such that the deck has a protruding tongue which extends out past the deck blank. The protruding tongue forms the bottom plate of the discharge spout. This reduces the number of parts necessary to assemble a terminal deck. It also provides a structurally stronger discharge spout than found in the prior art and reduces the time and labor necessary to assemble a terminal deck. This change in design also reduces fatigue cracking in the deck blank near the terminal deck discharge spout.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Priority is claimed from provisional application U.S. Ser. No. 60/281,546 filed on Apr. 4, 2001, and incorporated by reference herein. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     In general, the present invention relates to vibrating separators. In particular, the present invention relates to the design and fabrication of terminal decks typically used with vibrating separators. 
     2. Prior Art 
     Many industries utilize vibrating separators to classify certain solid materials by size or to separate solid material from liquid material. In either case, the material is fed to at least one screen surface which retains the oversize particles and allows the smaller particles or the liquid to pass therethrough. A vibrating, shaking or agitating motion is imparted to the screen to effect a more efficient separation and to move the oversize particles on the screen to a discharge area or chute generally located at the periphery of the screen. Specific applications range greatly from food processing to chemical processing to oil field production. In a typical food processing application, a vibrating separator is used to separate various food products according to their size. Vibrating separators used in the food processing industry must be built to exacting industry specifications for sanitation. In chemical processing applications, a vibrating separator can be used to remove particles or debris larger than a preset size from a slurry stream. Vibrating separators are also used in oil production. In oil production, the vibrating separator is typically used to remove larger pieces of debris from recirculated drilling fluids. 
     The vibrating separators of the prior art are generally constructed of the following major components. A separator blank generally consists of a cylindrical or box-shaped metal structure that is open at the top and bottom ends. Within the separator blank is a screen surface which has tiny openings sized to separate out particles of a particular size while liquids or smaller particles pass through. Located on the peripheral surface of the separator blank is a discharge spout which facilitates the removal of the particles which do not pass through the screen. If the vibrating separator is to be utilized to separate particles of more than one size in a single operation several separator blanks may be stacked on top of each other utilizing successively finer screen sizes. Where several separator blanks are used, the upper separator deck is called the spacing frame or top deck and each successive deck will be called a distribution frame or an intermediate deck. Functionally, without if a larger than normal motion generator, the mass of the decks make more than three or four decks prohibitive. 
     Located below the separator blank or blanks is a table frame or terminal blank so called because material will not continue through it, but rather will be directed towards the discharge spout on the outside of the blank. The terminal blank generally consists of a cylindrical or box-shaped metal structure constructed in a similar fashion to the separator blank with the exception that instead of a screen, the bottom of the terminal blank is enclosed by a terminal deck plate. The terminal deck plate consists generally of an elliptically-shaped metal sheet which is welded or otherwise secured to the inside of the terminal blank at an angle so as to provide a sloping surface that directs the flow of liquid or solid particles that pass though the screens of the separator deck or decks above to the discharge spout located on the peripheral wall of the terminal blank. The separator blank and terminal blank are attached together by bolts or by some type of fastening, clamping or latching means. Terminal decks come in basically two forms: scalping decks and table frame decks. The scalping deck is designed to allow large volumes of material to flow from the unit quickly. For this reason, it has a sloped surface. A table frame deck consists of a cylindrical body, discharge spout, and domed or convex terminal deck. The convex bottom acts to convey material falling from the screen above to the outside of the deck, then the motion of the machine will propel it toward and out of the spout. 
     The terminal deck and decks fastened to it are fastened to a motion generating assembly with bolts clamps or other fasteners. The motion generating assembly consists of a motor with eccentric weights fastened to a disk or annulus equal in diameter to the decks. 
     Vibration of the unit may be achieved by means of an electric, hydraulic, or pneumatic motor. While the vibrating motion of the vibrating separator allows for a great increase in efficiency over non-vibrating separator screens, the constant vibrating motion greatly increases the mechanical stresses on the equipment. The forces experienced can be in the range of 3 to 8 times the force of gravity. 
     One common result is stress cracks that form in the side of the terminal blank where the discharge spout is welded to the terminal blank. This failure is due to fatigue at the junction of the discharge spout and the terminal blank. The failure is accelerated by localized heat embrittlement of the metal resulting from welding. The terminal deck discharge spouts of the prior art were constructed separately from the blank. 
     Discharge spouts are generally comprised of three separate pieces of sheet metal cut and bent into shape and then welded together to form the separate terminal deck discharge spout. The discharge spout was then welded on to the outside wall of the deck blank. When the vibrating separator was put into service, the forces exerted on the discharge spout result in metal fatigue and stress cracks in the terminal blank where the weld joints are located. 
     Another problem present in the vibrating separators of the prior art is the weldjoint that joins the discharge spout to the terminal deck. In order for the vibrating separator to meet industry specifications for food grade equipment which are well known to those of ordinary skill in the prior art, the weld joints joining the discharge spout to the terminal deck must be ground smooth and polished. This extra step of grinding and polishing the weld is labor intensive and adds to the cost of manufacture of the vibrating separator. An example of a vibrating separator of this design is shown by U.S. Pat. No. 3,650,401 which shows a vibrating separator wherein the discharge spout is welded to the peripheral surface of the terminal blank with a joint where the terminal deck butts up against the discharge spout. Solutions offered in the prior art for the failure of terminal deck discharge spouts include gussets and stress relief straps. Others have simply used heavier metal on the deck and spout. 
     Another attempt to address the problems of the prior art is seen in U.S. Pat. No. 3,794,165 which discloses a terminal deck with a flange extending beyond the peripheral wall of the terminal blank forming a surface which supports the discharge spout but the flange does not actually form part of the spout itself. While the addition of this supporting flange would possibly help to prevent some of the metal stress to the terminal blank, this might increase the strength of the deck at the flange, but would not help the spout failure issue caused by stress where the spout meets the terminal blank. Moreover, the flange does not eliminate the weld joint where the terminal deck butts up against the discharge spout. 
     Thus, there is a need for a terminal deck assembly which provides greater support for the discharge spout thereby reducing the amount of metal fatigue resulting in greater service life. There is also a need for a terminal deck assembly which minimizes the number of welds which must be ground and polished at great expense of time and labor in order to meet industry specifications for food processing equipment. 
     BRIEF SUMMARY OF THE INVENTION 
     In general, the present invention is a new and improved terminal deck assembly for a vibrating separator which is formed from a single piece of sheet metal, such as but limited to, carbon steel, stainless steel, aluminum or another suitable metal. The terminal deck plate of the present invention differs from the prior art in that instead of an elliptical shape the terminal deck plate of the present invention incorporates a tongue which protrudes out through the wall of the terminal blank or container body forming the bottom of the discharge spout. The terminal deck plate of the present invention could also be square or rectangular or any other shape that corresponds to the shape and dimensions of the vibrating separator in which it is used. The terminal deck discharge spout is then fabricated out of two pieces of bent metal which are then welded onto the protruding tongue and the container body. The added support provided by the protruding tongue of the terminal deck plate greatly increases the structural strength of the joint between the discharge spout and the container body and results in increased service life of the equipment. In addition, the terminal deck plate of the present invention eliminates the weld joint between the terminal deck and the discharge spout resulting in labor and cost savings due to the reduction in the number of weld joints which must be ground and polished smooth in order to meet food industry specifications. The protruding tongue of the present invention can be incorporated into both scalping decks and table frame decks. 
     It is also contemplated that the terminal deck assembly and discharge spout could be constructed of a single sheet of metal with the spout being integral to the terminal deck plate and folded from a single sheet of metal. 
     In addition, it is contemplated that the terminal deck plate and spout assembly could be formed or molded as a single piece from plastic, a polymer material such as fiberglass, carbon fiber or any other similar material. The terminal deck plate and spout assembly could also be formed integral to the terminal blank assembly as a single piece formed or molded from plastic, a polymer material such as fiberglass, carbon fiber or any other similar material. 
     It is further contemplated that the vibrating separator of the present invention could be built with multiple stages with different sized separator means, such as but not limited to, screens in order to separate out different sized particles in a single operation. 
    
    
     Other objects and further scope of the applicability of the present invention will become apparent from the detailed description to follow, taken in conjunction with the accompanying drawings wherein like parts are designated by like reference numerals. 
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a vibrating separator with a terminal deck assembly constructed in accordance with the present invention. 
     FIG. 2 is a top view of a vibrating separator with a terminal deck assembly as shown in FIG.  1 . 
     FIG. 3 is a cross-sectional side view of a vibrating separator with a terminal deck assembly taken along section line  3 — 3  of FIG.  2 . 
     FIG. 4 is a top view of a terminal deck plate constructed in accordance with the present invention apart from the vibrating separator. 
     FIG. 5 is a side view of the terminal deck discharge spout constructed in accordance with the present invention. 
     FIG. 6 is a front view of the terminal deck discharge spout shown in FIG.  5 . 
     FIG. 7 is a bottom view of the terminal deck discharge spout shown in FIG.  5 . 
     FIG. 8 is a cross-sectional side view of a terminal deck assembly constructed in accordance with the present invention. 
     FIG. 9 illustrates a cross-sectional view of an alternate embodiment constructed in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings in detail, as shown FIG.  1  and designated by the general reference numeral  10  is a vibrating separator constructed in accordance with the present invention. The vibrating separator  10  generally comprises a base  20 , a terminal blank  40  and a separator blank  80 . As shown in FIG. 3, the base  20  has a first end  22 , a second end  24 , an outside surface  26  and an inside surface  28 . Attached to the first end  22  of the base  20  is the terminal blank  40 . 
     Now referring to FIGS. 3 and 4, the terminal blank  40  has a first end  42 , a second end  44 , an outside surface  46 , an inside surface  48  and a terminal deck discharge spout opening  58 . The second end  44  interfaces with an annular plate that is attached to the motion generator. This annulus or disk supports the terminal deck. In turn, the annulus/motion generator assembly is supported by the springs  29 . Also, attached to the first end  22  of the base  20  and the second end  44  of the terminal blank  40  is a motion generator  23  (illustrated as a box). The motion generator may take an number of forms as is known in the art. 
     Mounted to the inside surface  48  of the terminal blank  40  is a terminal deck plate  50 . The terminal deck plate  50  consists of an elliptically-shaped metal sheet with a protruding tongue  52 . The terminal deck plate  50  is welded or otherwise secured to the inside surface  48  of the terminal blank  40  at an angle so as to provide a sloping surface that directs the flow of liquid or solid particles to the terminal deck discharge spout opening  58 . The protruding tongue  52  is positioned so as to extend through the terminal deck discharge spout opening  58  of the terminal blank  40 . Welded to the outside surface  46  of the terminal blank  40  over the terminal deck discharge spout opening  58  is a terminal deck discharge spout  56 . 
     The terminal deck discharge spout  56 , shown in FIGS. 5-7, is constructed of a hood  70 , a down spout  72  and the protruding tongue  52 . The hood  70  and the down spout  72  are each formed of a single sheet of metal that is bent into shape. The hood  70  and the down spout  72  are welded together and then attached to the outside surface  46  of the terminal blank  40  with the protruding tongue  52  forming the bottom plate of the terminal deck discharge spout  56  (as shown in FIG.  3 ). 
     The first end  42  of the terminal blank  40  has a first flange  62 . Attached to the first end  42  of the terminal blank  40  is the separator blank  80 . The separator blank  80  has a first end  82 , a second end  84 , an outside surface  86  and an inside surface  88 . The second end  82  of the separator blank  80  has a second flange  96 . The separator blank  80  is attached to the terminal blank  40  by means of a coupling comprised of the first flange  62  of the terminal blank  40 , a circular ring  60 , a C-shaped band clamp  64 , a circular gasket  66  and the second flange  96  of the separator blank  80 . The circular ring  60  has an outside surface  59  and an inside surface  61 . The inside surface  61  is rolled to provide extra strength. The inside surface  61  of the circular ring  60  extends inwardly inside to the separator blank  80  and provides a circular shelf to support a screen  90 . The screen  90  is secured to the circular ring  60  by a center guide  53  and a center guide locking device  54 . When the vibrating separator  10  is in use, the motion generator  23  provides vibrational motion to the terminal blank  40  and the separator blank  80 . The product to be separated (not shown) enters through the top of the separator blank  80  and proceeds to flow through the screen  90 . Particles (not shown) which are larger than the holes (not shown) in the screen  90  are captured by the screen  90  and are conveyed by the vibration over to a separator blank discharge spout  92 . The majority of the product (not shown) continues through the screen  90  and onto the terminal deck plate  50  where it is conveyed by gravity and the vibration to the terminal deck discharge spout  56  and out of the vibrating separator  10 . 
     There are a number of advantages achieved. For example, the present invention reduces the costs of producing a food grade vibrating separator by eliminating the weld where the terminal deck discharge spout  56  is joined to the terminal deck plate  50 . 
     The present invention also provides for increasing equipment service life by reducing fatigue cracking of the terminal blank  40  where the terminal deck discharge spout  56  is welded to the terminal blank  40 . 
     An alternative embodiment of the present invention incorporating the present invention in a table frame terminal deck  67  is shown in the cross-sectional view shown in FIG.  9 . FIG. 9 shows the present invention incorporating a domed terminal deck  68  in place of the elliptically shaped terminal deck plate  50  as shown in FIG.  1 . In this alternative embodiment, the domed terminal deck  68  would be substantially circular and welded into the terminal blank  40 . The domed terminal blank  68  would have a protruding tongue  69  which would extend outside the terminal blank  40  and form part of the terminal deck discharge spout  56  of the vibrating separator  10 . 
     Another alternative embodiment of the present invention (not shown) incorporates a terminal deck and terminal deck discharge spout formed out of a single piece of sheet metal wherein the terminal deck discharge spout is cut folded and welded to form a spout that is integral to the terminal deck. 
     Another alternative embodiment of the present invention (not shown) incorporates a terminal deck plate and terminal deck discharge spout wherein a terminal deck plate and terminal deck discharge spout are formed or molded as a single piece from a polymer material such as plastic, fiberglass, carbon fiber or any other similar material. 
     Another alternative embodiment of the present invention (not shown) incorporates a terminal blank wherein the terminal blank, terminal deck plate, and terminal deck discharge spout are formed or molded as a single piece from a polymer material such as plastic, fiberglass, carbon fiber or any other similar material. 
     Another alternative embodiment of the present invention (not shown) incorporates a top blank and multiple intermediate blanks with progressively finer screen sizes stacked on top of each other so that particles of different sizes may be separated out in a single operation. 
     Another alternative embodiment of the present invention incorporates the terminal deck plate of the present invention in a rectangular or box shaped vibrating separator. 
     Yet another alternative embodiment of the present invention incorporates a single container body which incorporates a separator means such as a screen, a terminal blank and a terminal blank discharge spout. 
     While this invention has been described to illustrative embodiments, this description is not to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments will be apparent to those skilled in the art upon referencing this disclosure. It is therefore intended that this disclosure encompass any such modifications or embodiments.