Abstract:
A vibratory conveyor employing an amplitude compensator to substantially impede the conveyor bed from moving beyond a given range of vibration amplitude is described. The amplitude compensator coacts with the conveyor bed as the vibrational amplitude of the bed increases in response to an increase in the mass of conveyed product, or to an increase in the vibrational force produced by the vibratory drive to impede or substantially eliminate premature wear or mechanical failure of leaf springs which support the bed.

Description:
TECHNICAL FIELD 
     The present invention relates to a vibratory conveyor and more specifically to an improved spring for use with same. 
     BACKGROUND OF THE INVENTION 
     Excited frame vibratory conveying devices are known in the art. U.S. Pat. No. 4,313,535, incorporated by reference herein, teaches a typical excited frame conveying apparatus. An apparatus such as this generally includes a vibratory drive mounted on an elongated frame and which rests on a floor or other supporting structure. Extending upwardly from the frame, and inclined in the direction of the infeed end of the conveyor are a plurality of leaf springs. An elongated conveyor bed is mounted on the distal ends of the leaf springs and is supported by them such that the bed is generally parallel to the frame and oriented in a substantially horizontal position. 
     Due to the resiliency of the leaf springs, the bed is capable of moving relative to the frame in response to a force applied to the bed by the vibratory drive. During operation of the conveyor, the vibratory drive produces an oscillating vibratory force. This vibratory force is usually generated by counter-rotating eccentric weights which are subcomponents of the vibratory drive. Because the vibratory drive is mounted on the frame, it imparts vibratory motion to the frame which is transferred through the leaf springs to the bed. Thus, the bed vibrates at substantially the same frequency as the drive and frame. 
     In operation, if the bed is displaced from its “at rest” position and then allowed to oscillate freely, it will oscillate at its natural or “harmonic” frequency. This natural frequency of the bed is dependent on both the combined spring constant of the springs supporting the bed as well as the mass of the bed. Generally, at frequencies near the natural frequency of the bed, the vibration of the vibratory drive is amplified significantly by the springs, resulting in substantially more movement of the bed than the frame. The maximum vibrational amplitude of the bed is attained when the frequency of the vibratory drive is the same as the natural frequency of the bed and springs. 
     In view of the design of the leaf springs, the bed supported by same is restricted to a given range of motion. In particular, the bed and frame remain substantially parallel to each other at all times. As the bed vibrates freely, it moves in a first direction that is generally upward and toward the outfeed end of the conveyor and then in a second, and opposite direction that is generally downward and toward the infeed end of the conveyor. This vibratory motion of the bed tends to “bounce” the product along the bed from the infeed end to the outfeed end. 
     As compared to other types of vibratory conveyors, less vibration is transferred to the floor or other supporting structure by an excited frame design because of its relatively light weight and small vibration amplitude of the frame compared to the vibration amplitude of the bed. The low level of vibration transferred to the surrounding structure is a chief advantage of the excited frame vibratory conveyor. 
     While vibratory conveyors have operated with varying degrees of success in handling various products, there have been shortcomings which have detracted from their usefulness. For example, if the vibrational amplitude of the bed is allowed to become too great, the leaf springs supporting same become repeatedly over-stressed. This results in premature wear and sometimes failure of the springs. This problem stems, in part, from the nature of the prior art excited frame design, inasmuch as the bed is allowed to vibrate freely in response to changing conditions which affect the vibrational amplitude of the bed. 
     In addition to the foregoing, commercial operators of vibratory conveyors want the conveyors to be as versatile as possible. For example, the operators want the conveyor to be able to handle a wide array of products at different conveying speeds. Thus, an operator of a vibratory conveyor often wants to control both the frequency of vibration and the amplitude of vibration of the bed in order to control the conveying speed of the product. Also, the operator may wish to adjust both the frequency and amplitude to avoid damage to more fragile or delicate products. 
     Generally then, it is desirable for the frequency of vibration to be directly correlated to the amplitude of vibration since both contribute to the conveying speed. In other words, it is usually desirable for the vibration amplitude to increase as the vibration frequency increases and vice versa, since both the amplitude and frequency are generally directly related to conveying speed. If the vibratory drive is operated at frequencies that are below the natural frequency of the bed, an increase in the frequency of the vibratory drive will bring the frequency of the vibratory drive closer to the natural frequency of the bed, thus increasing the vibrational amplitude of the bed. Therefore, the vibratory drive is usually operated at a frequency that is less than the natural frequency of the system to ensure a direct correlation of the frequency and amplitude of the bed. 
     As a general matter the natural frequency of the bed is inversely proportional to the mass of the bed. In other words, the heavier the bed, the lower its natural frequency. As a practical matter, the mass of the bed also includes the product being supported by the bed. Thus, as the mass of the product on the bed increases, the natural frequency of the bed will decrease. As mentioned above, the vibratory drive is generally operated at a frequency that is lower than the natural frequency of the bed. Consequently, as the mass of the product on the bed increases and the frequency of the vibratory drive remains constant, the natural frequency of the bed will decrease and approach the frequency of the vibratory drive, which in turn, results in an increase in the vibrational amplitude of the bed. As will be readily recognized the mass of beds in most commercial environments will be changing dynamically over time in view of day to day manufacturing contingencies. 
     As should be understood, the degree of amplification of the vibration produced by the vibratory drive increases exponentially as the frequency of the vibration approaches the natural frequency of the bed. Generally, the degree of amplification is limited only by any frictional damping forces present in the system, which in a conveyor of this type is generally negligible. Thus, as the frequency of the drive and the natural frequency of the bed approach one another, the amplitude of the bed increases to a degree which encourages the premature failure of the springs. 
     As noted above, in a commercial environment, the mass of the product on the conveyor bed can change dynamically over time. For example, if a downstream stoppage occurs, product may back up along the production line and become more densely packed on the conveyor bed. Also, certain types of product may contain substances which adhere to the conveyor bed, causing a buildup of the same substance on the bed, resulting in an increased mass of the bed. Still further, a product may be processed which has a higher density than that for which the conveyor was originally designed. 
     In addition to the foregoing, while the vibrational amplitude of the bed will generally increase in response to an increase in the mass of the bed, the amplitude will also generally increase in response to an increase in the frequency of the vibratory drive. For example, the operator of the conveyor may increase the vibrational frequency of the vibratory drive in an effort to increase the conveyed speed of the product. Varying the frequency of the vibratory drive is accomplished by varying the speed of the motor which drives the eccentric weights, such as by using a variable speed drive unit in conjunction with an a/c motor. An increase in the speed of the motor will increase the frequency of the vibratory drive, bring the bed closer to its natural frequency, resulting in an increase in the vibrational amplitude of the bed. 
     In both cases noted above, whether by an increase in the vibrational frequency of the drive or, by an increase in the mass of the bed, the vibrational amplitude of the bed may increase to unsatisfactorily high levels, thereby encouraging the premature failure of the associated springs and possibly damage to other parts of the conveyor or adjacent processing equipment. Thus, an excited frame conveyor must normally be monitored closely by an operator so that the frequency of the drive remains sufficiently below the natural frequency of the bed in order to prevent premature failure of the springs. This can sometimes be difficult if not impossible to accomplish given the changing nature of the bed mass in response to changing product manufacturing and processing conditions. 
     To address these perceived disadvantages, users of such devices have considered lowering the drive frequency to compensate for increased bed mass. However this has not been satisfactory because this will generally result in an undesirably slow conveying speed. Yet further, the installation of enhanced springs will not solve the problem, but will simply increase the natural frequency of the bed, which inturn, will require a correspondingly higher operating frequency of the vibratory drive in order for the excited frame conveyor to function properly. 
     Therefore it has long been known that it would be desirable to provide a vibratory conveyor which achieves the benefits to be derived from similar prior art devices and assemblies, but which avoids the shortcomings and detriments individually associated therewith. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the invention are described below with reference to the following accompanying drawings. 
     FIG. 1 is a perspective view of the vibratory conveyor apparatus of the present invention. 
     FIG. 2 is a side elevation view of the vibratory conveyor shown in FIG. 1 with some underlying surfaces shown in phantom line. 
     FIG. 3 is a fragmentary, perspective view of an amplitude compensator which is utilized with the vibratory conveyor shown in FIGS. 1 and 2. 
     FIG. 4 is an enlarged, fragmentary side elevation view of the vibratory conveyor shown in FIGS. 1 and 2 and showing different positions of the conveyor bed as it moves in response to vibratory motion imparted to it by the vibratory drive. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws “to promote the progress of science and useful arts” (Article 1, Section 8). 
     In accordance with one aspect of the present invention, a vibratory conveyor apparatus comprises a frame; a drive assembly borne by the frame for imparting vibratory motion to the frame; a first resilient member mounted on the frame; a bed mounted on the first resilient member, the first resilient member transmitting the vibratory motion from the frame to the bed; and an amplitude compensator mounted on the vibratory conveyor to substantially impede the bed from traveling outside a given range of motion as the bed moves in response to the vibratory motion. 
     Another aspect of the present invention relates to a vibratory conveyor apparatus for moving particulate matter comprising a frame; a drive assembly borne by the frame and operable to impart vibratory motion to the frame; a plurality of resilient members borne by the frame, each resilient member having a predetermined range of motion; a bed mounted on the resilient members, and wherein the vibratory motion imparted to the frame is transmitted to the bed by the resilient members to cause the bed to reciprocate along a given path of travel relative to the frame; and wherein the path of travel is defined between a forwardmost position, and a rearwardmost position, and wherein the reciprocating movement of the bed along the path of travel has a given amplitude; and an amplitude compensator mounted on the frame which coacts with the bed and substantially impedes the bed from traveling beyond the given path of travel. 
     Yet another aspect of the present invention relates to a vibratory conveyor apparatus for moving particulate matter comprising a frame; a drive assembly borne by the frame and operable to impart vibratory motion to the frame, the vibratory motion having a predetermined frequency; a plurality of first leaf springs borne by the frame, and wherein the first leaf springs are substantially parallel, one to another, and oriented at an oblique angle relative to the bed, and wherein each of the first leaf springs has a predetermined range of motion; a bed mounted on and supported by the first leaf springs, and wherein the vibratory motion imparted to the frame is transmitted to the bed by each of the first leaf springs to cause the bed to reciprocate relative to the frame, and wherein the bed has a path of travel which comprises a reciprocating displacement which is defined between a first position and a second position, and wherein the movement of the bed has an amplitude which varies in proportion to the frequency of the vibratory motion and to a mass density of the particulate matter supported by the bed; and an amplitude compensator comprising a second leaf spring mounted on the frame and which acts on the bed to limit the amplitude of movement of the bed along the path of travel and substantially impede the first leaf springs from traveling outside the predetermined range of motion. 
     The apparatus of the subject invention is best understood by a study of FIGS. 1 and 4 and is generally indicated by the numeral  10 . As shown in FIG. 1, the apparatus  10  rests on the surface of the earth  11  and is supported in rolling engagement therewith by a plurality of castors  12  of conventional design. The castors are affixed by conventional fastening means to a leg generally designated by the numeral  13 . Each leg has a proximal end  14  which is affixed to the respective castors  12  and an opposite distal end  15  which is remote thereto. The distal end of each of the legs  15  is received in an adjustment fixture  20 . The adjustment fixture, in combination with the distal end of each of the legs, allows the apparatus  10  to be positioned in various locations above the surface of the earth  11 . The vibratory conveyor apparatus  10  includes a frame generally designated by the numeral  30  and which is mounted in substantially parallel spaced relationship to the surface of the earth  11 . The frame  30  is generally rectangular and has a first end  31  and an opposite second end  32 . Still further, the frame is defined by substantially elongated siderails designated by the numeral  33 . Each of the siderails have an outside facing surface  34 , and an opposite, inside facing surface  35 . 
     As best seen in FIGS. 1 and 2, a vibratory drive generally designated by the numeral  40  is borne by the frame  30  and is operable to impart vibratory motion to the frame. The vibratory motion is directed along a line of force which is generally designated by the numeral  41  in FIG.  2 . The vibratory drive used with the present device has been described in U.S. Pat. No. 4,313,535 which is incorporated by reference herein. The vibratory drive, as used in the present invention, includes a variable speed motor which allows the frequency of the vibratory drive to be changed. Variable speed motors are well-known to those in the art. 
     As best seen by reference to the exploded view shown in FIG. 3, a plurality of lower mounting fixtures generally designated by the numeral  50  are affixed by welding or suitable fasteners to the inside facing surface  35  of each of the rails  33 . These lower mounting fixtures are mounted at predetermined substantially equally spaced locations along each of the rails. Each of the lower mounting fixtures  50  have a baseplate  51  which is affixed to the inside facing surface  35 . This can be accomplished by welding or other suitable fasteners as indicated above. Still further, a post  52  is mounted to or otherwise made integral with baseplate  51  and extends substantially normally outwardly therefrom. The post  52  has a pair of apertures  53  formed therein. 
     As seen in FIGS. 1,  2  and  4 , the vibratory conveyor apparatus  10  includes a first resilient member generally indicated by the numeral  60  and which usually comprises a plurality of pairs of first leaf springs designated by the numeral  60 . These leaf springs are well understood in the art and are made from various materials appropriate for the conveyor bed which is supported by same. The conveyor bed will be discussed in further detail hereinafter. As seen in FIG. 4, each pair of first leaf springs  60  have respective first ends  61  and opposite distal ends  62 . As best appreciated by a study of FIGS. 2 and 4 the proximal or first ends  61  are affixed by a pair of fasteners, not shown, which are received through the individual springs  60  and which further pass through the lower mounting fixtures  50  by way of the apertures  53 . As seen by reference also to FIG. 2 the vibratory conveyor apparatus  10  also includes upper mounting fixtures  70  which have a design which is substantially similar to the lower mounting fixtures  50 . The upper mounting fixtures include a baseplate  71 , and a post  72  which is affixed thereto. In similar fashion as that shown with respect to the lower mounting fixtures  50 , apertures, not shown, are formed in the post  72  and suitable fasteners are received through the distal ends  62  of each of the leaf springs and through the apertures formed in the post  72  thereby securing the distal ends of each of the leaf springs  62  to the upper mounting fixture  70 . As seen most clearly by reference to FIG. 4, the plurality of resilient members or first leaf springs  60  which are borne by the frame each have a predetermined range of motion which is designated by the line labeled  73 . This range of motion is defined between a forwardmost position  74  and a rearwardmost position  75 . As should be understood, vibratory motion imparted to the frame  30  is transmitted to the resilient members  60  borne by the frame to cause the resilient members  60  to move along this given range of motion  73 . As discussed earlier, encouraging the first leaf springs  60  to exceed this given range of motion  73  has the propensity for facilitating the premature failure of the respective first leaf springs  60 . 
     As best seen by reference to FIGS. 1,  2  and  4 , the vibratory conveyor apparatus of the subject invention  10  includes a conveyor bed which is generally indicated by the numeral  80  and which is mounted on the first resilient members  60 . As earlier noted, the first resilient members transmit vibratory motion from the frame  30  to the conveyor bed  80 . The conveyor bed  80  is of substantially conventional design having a first or intake end  81 , and an opposite, second, or exhaust end  82 . The conveyor bed defines a supporting surface  83  having a uppermost or top surface  84  and a lowermost or bottom surface  85 . As best seen in FIG. 2, the top or uppermost surface  84  supports product  86  which travels therealong to the exhaust end  82  for further processing by other equipment, not shown. While the product is shown generally as having a round or spherical configuration, it will be recognized that products of varying shapes may be utilized with a conveyor of this design. The conveyor bed  80  further includes a pair of substantially parallel siderails  90  which are mounted on the product supporting surface  83  and define a channel  87  which limits the lateral motion of the product  86 . Each of the siderails  90  extend substantially normally upwardly from the surface  83 . Each of the siderails  90  have an inside facing surface  91 , and an outside facing surface  92 . As best seen by reference to FIG. 2, the upper mounting fixtures  70  are affixed by a suitable fastening technique such as welding, fasteners or the like at predetermined given substantially equally spaced locations along the outside facing surface  92  of the respective siderails  90 . As best seen by reference to FIG. 4, the vibratory motion imparted to the conveyor bed  80  comprises a reciprocating movement along a given range of motion  100  between a first or forwardmost position  101 , and a second or rearwardmost position  102 . This range of motion or path of travel has a given amplitude based upon mass of the conveyor bed  80  and the product which is carried or supported by same. This matter was discussed earlier in this application. As noted above, exceeding the given amplitude of the conveyor bed can cause deleterious effects to the underlying first leaf springs  60  which are supporting the conveyor bed  80 . 
     An amplitude compensator is generally indicated by the numeral  120  in FIGS. 1-4, respectively. As best understood by a study of FIGS. 2 and 3, respectively, the amplitude compensator comprises a pair of second leaf springs or resilient members  121  which are mounted on the frame  30  and which coact with the conveyor bed  80  to limit the amplitude of the movement of the conveyor bed  80  along the range of motion or path of travel  100 , and further to substantially impede the first leaf springs  60  from traveling outside the predetermined range of motion  73 . As such, the amplitude compensator prevents the premature deleterious degradation of the plurality of first leaf springs  60  as might be caused from time-to-time in those circumstances whereby the vibratory conveyor apparatus  10  is being operated in such a fashion as to encourage the amplitude of the conveyor bed  80  to move beyond what is reasonably prudent, or advisable. As noted earlier, the conveyor bed  80  moves along a path of travel  100  comprising a reciprocating displacement which is defined between a first or forwardmost position  101  and a second or rearwardmost position  102 . This reciprocating displacement or other movement of the conveyor bed  80  has an amplitude which varies in proportion to the frequency of the vibratory motion and to a mass density of the particulate matter or product  86  which is being supported by the conveyor bed  80 . As such, the amplitude compensator substantially impedes the first leaf springs from traveling outside the predetermined range of motion  73 . 
     As noted above, the amplitude compensator  120  includes a second pair of resilient members generally designated by the numeral  121 . These second resilient members or second leaf springs  121  have a given length dimension and further have opposite first and second ends  122  and  123 , respectively. As seen in FIG. 3, each of the second resilient members have a pair of apertures  124  formed in the first end thereof and a second pair of apertures  125  which are formed therein, and which are spaced a given distance from the second end  123  thereof. A cushion pad  126  is mounted on the second end  123  of each of the second resilient members  124 . 
     As best understood by a study of FIG. 3, a plurality of third leaf springs  140  are mounted in juxtaposed, predetermined, substantially parallel relation relative to the second pair of leaf springs  121 . The third leaf springs  140  have an overall length dimension which is less than the length dimension of the second resilient members. The third leaf springs  140  each have a first end  141  and an opposite second end  142 . A pair of apertures  143  and  144 , respectively, are formed in the first and second ends, respectively. These apertures are oriented such that they are substantially coaxially aligned with the apertures  124 , and  125  which are formed in the second pair of leaf springs  121 . This is illustrated most clearly by reference to FIG.  3 . 
     A spacing block generally designated by the numeral  150  is mounted between each of the second leaf springs thereby locating the respective second leaf springs in predetermined spaced relationship one to the other. The spacing block  150  has a pair of apertures  151  formed therein which are coaxially aligned with the apertures  125  and  142  formed in the respective second and third leaf springs  121  and  140 , respectively. The spacing block has a given thickness dimension. Smaller mounting plates  160  having apertures  161  formed therein are suitably positioned outwardly of the second leaf springs  121  and threaded fasteners  170  are provided which are received in the coaxially aligned apertures of the respective subassemblies. Suitable nuts  171  threadably engage the fasteners  170  thereby providing the sandwich like construction shown in FIG.  4 . As will be recognized by a study of FIG. 4, the amplitude compensator  120  defines a given space  180  between the second ends  123  of the respective second resilient members  121 . 
     As best understood by reference to FIG. 3, the amplitude compensator  120  further comprises a contact member generally designated by the numeral  190  which is mounted on the outside surface  92  of the conveyor bed  80  and which is operable to impinge against the second end  123  of the respective second leaf springs  121  when the conveyor bed moves along the range of motion or path of travel  100  between the first or forwardmost position  101  and the second and rearwardmost position  102 . As will be recognized, if the conveyor bed  80  moves beyond the range of motion or path of travel  100  the contact member  190  is oriented such that it impinges alternatively against each of the pair of second leaf springs thereby substantially impeding the motion of the conveyor bed  80  beyond the predetermined range of motion. 
     The contact member  190  has a baseplate  191  which is affixed by welding or the like on the outside facing surface  92  of the respective siderails  90 . A post  192  is welded or otherwise made integral with the baseplate and is oriented in the space  180  defined between the second ends  123  of the pair of second resilient members or leaf springs  121 . A cushioning surface  193  is mounted on the post and is operable to dampen the noise caused by any impingement of the second leaf springs  121  by coacting with the pad  126  mounted on the second resilient members  121  against the post  192 . It should be recognized that the post  192  and the cushioning surface  193  have a given thickness dimension. As shown it should be understood that the thickness dimension of the spacing block  150  is greater than the combined thickness dimension of post  192  and cushioning surface  193 . It should also be understood that the movement of the conveyor bed  80  beyond a given amplitude causes the amplitude compensator  120  to transmit a given force between the conveyor bed  80  and the frame  30 . Still further this given force is substantially parallel to the movement of the conveyor bed  80  and the given force is substantially proportional to the amplitude of movement of the conveyor bed along the path of travel  100 . 
     OPERATION 
     The operation of the described embodiment of the present invention is believed to be readily apparent and is briefly summarized at this point. 
     As earlier discussed, the vibratory conveyor apparatus  10  of the subject invention comprises a frame  30 ; a drive assembly  40  borne by the frame for imparting vibratory motion to the frame  30 ; a first resilient member  60  mounted on the frame  30 ; a bed  80  mounted on the first resilient member  60 , the first resilient member transmitting the vibratory motion from the frame  30  to the bed  80 ; and an amplitude compensator  120  mounted on the frame to substantially impede the bed from traveling outside a given range of motion  100  as the bed  80  moves in response to the vibratory motion. As earlier discussed, the vibratory conveyor  10  and in particular the amplitude compensator  120  comprises a second resilient member  121  which impedes the bed  80  from moving outside the given range of motion  100  by transmitting a given force between the bed  80  and the frame  30 . This given force is produced when the bed  80  deforms the second resilient member  121 . This deformation occurs as the contact member  190  moves against same. As noted above, the vibratory motion of the bed  30  comprises a reciprocating movement along a given path of travel or range of motion  100  which is defined between a first or forwardmost position  101  and a second or rearwardmost position  102 . As should be understood, an amplitude compensator is mounted on opposite sides of the vibratory conveyor  10  although only one is shown in the drawings. 
     As earlier discussed, the amplitude compensator  120  which is mounted on frame  30  coacts with conveyor bed  80  to substantially impede the bed from traveling beyond the given path of travel  100 . Still further, the amplitude compensator, including the second leaf springs  121  have a range of motion when deformed. It being understood that this range of motion is substantially parallel to the path of travel of the bed. 
     Therefore, a vibratory conveyor apparatus  10  for moving particulate matter  86  includes a frame  30 ; a drive assembly  40  borne by the frame  30  and operable to impart vibratory motion to the frame  30 , the vibratory motion having a predetermined frequency. As noted earlier, a plurality of first leaf springs  60  are borne by the frame  30  and wherein the first leaf springs  60  are substantially parallel, one to another, and oriented at an oblique angle relative to the frame, and wherein each of the first leaf springs has a predetermined range of motion. A bed  80  is mounted on and supported by the first leaf springs  60  and wherein the vibratory motion imparted to the frame  30  is transmitted to the bed  80  by each of the first leaf springs  60  to cause the bed  80  to reciprocate relative to the frame. The bed  80  has a path of travel  100  which comprises a reciprocating displacement which is defined between a first position  101  and a second position  102 . The movement of the bed  80  has an amplitude which varies in proportion to the frequency of the vibratory motion and to a mass density of the particulate matter  86  supported by the bed  80 . An amplitude compensator  120  comprising a second leaf spring  121  mounted on the frame  30  and which coacts with the bed  80  to limit the amplitude of the movement of the bed along the path of travel is seen in FIG.  3 . The amplitude compensator  120  and the second leaf spring  121  in particular, substantially impedes the first leaf springs  160  from traveling outside the predetermined range of motion  73 . In the event that the bed  80  moves outside the given range of travel  100  the contact member  190  impinges against the second end  123  of the respective second leaf springs  121  thereby transmitting a force between the bed  80  and the frame  30  substantially impeding further movement of the bed beyond the given range of motion. 
     Therefore it will be seen that the vibratory conveyor apparatus  10  of the subject invention provides a convenient means whereby particulate matter  86  can be moved efficiently along a vibratory conveyor and which further avoids the detriments individually associated with utilizing a vibratory conveyor of more traditional design. 
     In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents.