Abstract:
A conveyor assembly to deliver flavoring to a conveyor upon which a product to be coated is conveyed. The flavoring is typically in granular form such as a powder. The assembly includes a conveyor including a longitudinally elongated tray that is vibrated by an actuator. The tray and actuator are adapted to distribute the flavoring transversely across the conveyor.

Description:
This application claims priority to Australian Provisional Application No. 2011902602, filed Jun. 30, 2011, the entirety of which is incorporated by reference herein. 
     TECHNICAL FIELD 
     The present invention relates to conveyors that convey a flowable substance in granular (including powder) form, and more particularly but not exclusively to conveyors that deliver the flowable substance for the purposes of coating product on another conveyor to which the substance is delivered. 
     BACKGROUND OF THE INVENTION 
     In the snack food industry many snack foods are coated with a flavouring. There are machines that provide for the coating of the snack food, such as the machine described in U.S. Pat. No. 7,878,142. 
     A disadvantage of some previous machines is that they do not uniformly coat the snack food and/or have significant waste. 
     A further disadvantage of some previous machines is that they can be complex and therefore unreliable. 
     A still further disadvantage of some previous machines is that they are frequently difficult to clean. 
     Object of the Invention 
     It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages. 
     SUMMARY OF THE INVENTION 
     There is disclosed herein a conveyor assembly to deliver a flowable substance in granular form, said assembly including: 
     an elongated tray having a longitudinal axis and a floor provided to receive the substance, the floor sloping downward from a substance receiving portion to a substance delivery portion; 
     an actuator to cause vibration of the tray to cause the substance to travel along the floor from the receiving portion to the delivery portion at which the substance is delivered from the floor; and wherein 
     said delivery portion includes an edge of the floor so the substance falls from the floor, and said actuator vibrates the floor at a frequency with an amplitude with a vertical component, with said frequency being at least 20,000 hz. 
     Preferably, the frequency is less than 70,000 hz. 
     Preferably, the frequency is 30,000 hz to 40,000 hz. 
     More preferably, the frequency is 36,000 hz to 38,000 hz. 
     Preferably, said amplitude has effectively a negligible horizontal component. 
     Preferably, said horizontal component is approximately zero. 
     There is still further disclosed herein a conveyor assembly to deliver a flowable substance in granular form, said assembly including: 
     an elongated tray having a longitudinal axis and a floor provided to receive the substance, the floor sloping downwardly from the substance receiving portion to a substance delivery portion; 
     an actuator to cause vibration of the tray to cause the substance to travel along the floor from the receiving portion to the delivery portion at which the substance is delivered from the floor; and wherein 
     the floor at the delivery portion including an edge so that the substance falls from the floor, and said actuator vibrates the floor at a frequency with an amplitude extending generally perpendicular to said axis. 
     Preferably, said frequency is at least 20,000 hz. 
     Preferably, said frequency is less than 70,000 hz. 
     Preferably, the frequency is 30,000 hz to 40,000 hz. 
     More preferably, the frequency is 36,000 hz to 38,000 hz. 
     Preferably, the amplitude is l μm to 130 μm. 
     Preferably, the amplitude is 2.5 μm to 5 μm. 
     Preferably, the amplitude has affectively no component parallel to said axis. 
     Preferably, said amplitude has approximately zero component parallel to said axis. 
     Preferably, said actuator is attached to said tray by a coupling member, with said tray having a bottom surface to which the coupling member is directly attached. 
     Preferably, the tray and coupling member have a resonant frequency at approximately the frequency provided by the actuator. 
     Preferably, said edge is generally linear so as to have a direction of extension transverse of said axis and parallel to said axis. 
     Preferably, the edge has a length in the direction of extension parallel to said axis and a length in the direction transverse of said axis that is less than the length in the direction of extension parallel to said axis. 
     Preferably, the tray is inclined by 1° to 10° to the horizontal. 
     Preferably, the tray is inclined by 3° to 5° to the horizontal. 
     There is further disclosed herein, the above assembly and a further conveyor, and wherein said edge extends generally transverse of further conveyor so that the substance is spread transversely across the further conveyor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings wherein: 
         FIG. 1  is a schematic isometric view of portion of an assembly to deliver a flowable substance in granular form to a conveyor; 
         FIG. 2  is a schematic top plan view of the machine of  FIG. 1 ; 
         FIG. 3  is a schematic front elevation of the machine of  FIG. 1 ; and 
         FIG. 4  is a schematic rear elevation of the machine of  FIG. 1 ; 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the accompanying drawings there is schematically depicted a conveyor assembly  10 . The assembly  10  delivers flavouring to a conveyor  11  upon which there is conveyed a product to be coated. The flavouring would be in granular forms, this includes the flavour being a powder. As a particular example, the assembly  10  may deliver a flavouring to a snack food being conveyed by the conveyor  11 . Although many types of different conveyors may be employed, typically the conveyor  11  would be a slip conveyor having a longitudinally extending tray  13  that includes a pair of longitudinally extending side walls  12  between which a tray floor  14  extends. The tray  13  would be reciprocated in the direction  15  so as to convey product in the longitudinal direction  16 . Typically the snack food would be distributed transversely across the tray  13 . 
     The assembly  10  includes a conveyor  17  consisting of a longitudinally elongated tray  23  that is vibrated by an actuator  19 . Preferably the actuator  19  is electrically operated and provides a vibration in the frequency range of 20,000 hz to 70,000 hz, most preferably about 36,000 hz to 38,000 hz. Supporting the tray  23  is a shaft  20  that is fixed to the tray  23 . The shaft  20  is supported by a collar  21 , with the collar  21  being mounted on a bracket  22 . The actuator  19  is also mounted on the bracket  22  so as to be supported thereby. 
     The tray  23  includes a pair of longitudinally extending sides  24  between which there is located a longitudinally extending floor  25 . The sides  24  extend upwardly from the tray floor  25 . The shaft  20  is fixed to the bottom surface of the tray  23 . 
     The actuator  19  vibrates the floor  25  so that the floor  25  has an amplitude with a vertical component, and most preferably with a vertical component and essentially negligible or zero horizontal component. In an alternative preferred from, the actuator  19  vibrates so as to vibrate the floor  25  so as to have an amplitude with a component perpendicular to the longitudinal axis  30 , and most preferably with a component perpendicular to the axis  30  with essentially negligible or zero component parallel to the axis  30 . When vibrated at the above frequency, the flavouring delivered to the tray  13  is essentially “fluidised”. Preferably, the actuator  19  is a ultra high frequency (ultra-sonic frequency) “Sonotrode” actuator. Typically the actuator  19  would be a piezo electric motor with a vertical amplitude (or an amplitude perpendicular to the axis  30 ) of between 1.0 μm and 130 μm, preferably 2.5 μm to 5 μm. 
     Preferably, the floor  25  is inclined to the horizontal by an acute angle of 1° to 10° , preferably about 3° to 5°. 
     The tray  23  has a receiving portion  26  to which the flavouring is delivered, and a delivery portion  27 . The delivery portion  27  includes an edge  28  of the floor  25 , the edge  28  extending at an acute angle  29  to the longitudinally axis  30  of the tray  23 . The edge  28  has a major direction of extension parallel to the axis  30  as well as a direction of extension in a lateral direction perpendicular to the axis  30  so as to be inclined by the angle  29 . The length of the edge  28  is greater in the longitudinal direction than the length of the edge  28  in the lateral direction, i.e. the angle  29  is less than 45°. 
     Vibration of the tray  23  (floor  25 ) causes the flavour to travel in the direction  31  from the receiving portion  26  to the delivery portion  27  as the floor slopes downwardly at an acute angle from the receiving portion  26  to the delivery portion  27 . Ultimately product passing along the tray  23  reaches the edge  28  at which time it falls from the edge  28  to be deposited on product on the floor  25  of the tray  13 . The product is coated by the flavouring. As the edge  28  extends substantially across the entire width of the floor  25 , product scattered across the floor  25  is coated. 
     Preferably, the direction  31  is generally perpendicular to the direction  16 . 
     The flavour is delivered to the tray  23  from a flavour delivering assembly  32 . The assembly  32  includes a hopper  33  that stores a volume of the flavouring in granular or powder form. The hopper  33  communicates with an auger assembly  34  that delivers the flavouring to a tube  35  via which the flavouring is delivered to the tray  23  at the delivery portion  26 . The auger assembly  34  would include an auger that passes through the lower end of the hopper  33 , or is in communication with the lower end of the hopper  33 , with the auger being driven by a motor and gearbox assembly  36 .