WO2021081621A1

WO2021081621A1 - System for delivering doses of ground cannabis

Info

Publication number: WO2021081621A1
Application number: PCT/CA2020/000123
Authority: WO
Inventors: Jean Pierre PERREAULT; Blair SACHS
Original assignee: Plan Automation Lp Inc.
Priority date: 2019-11-01
Filing date: 2020-10-30
Publication date: 2021-05-06

Abstract

A system for delivering doses of ground cannabis. The system includes a hopper, a screw auger feed mechanism, and a servo motor drive. The hopper is for containing a bulk quantity of the ground cannabis. The screw auger feed mechanism is for delivering the doses of the ground cannabis from the hopper. The servo motor drive is for driving the screw auger feed mechanism. The screw auger feed mechanism comprises an auger that is received within a sleeve. The sleeve has a first longitudinal end and a second longitudinal end. The auger is supported at both the first longitudinal end and the second longitudinal end to prevent floating of the auger in the sleeve. The screw auger feed mechanism has a partially enclosed discharge port for directing the doses of the ground cannabis in a desired direction.

Description

Title

SYSTEM FOR DELIVERING DOSES OF GROUND CANNABIS Cross-Reference to Related Application

[0001] This application claims the benefit of the November 1, 2019 filing date of United States Provisional Patent Application 62/929292 entitled “Positive Drive Cannabis Feed System”, which is incorporated herein by reference.

Field of the Invention

[0002] This invention relates to systems for delivering small, measured doses of a product, and more particularly to systems for delivering doses of ground cannabis.

Background of the Invention

[0003] Cannabis producers packaging flower/bud product are typically required to meet strict guidelines that require net product weight per package to be controlled in a manner that protects the consumer from receiving packages containing less product than stated on the package. Deviations are typically limited to plus or minus 10%. Penalties for underweight product, combined with variances in fill weight normal to most automated processes, force producers to set their fill weights higher than the nominal product weight to prevent normal production variances from delivering underweight packages to the consumer. Therefore, during a typical production run a certain percentage of the product input to the packaging system will inevitably be incorporated in the final product as “giveaway”, or excess product over the nominal package weight that is non-chargeable and therefore directly erodes profitability.

[0004] Cannabis flower products present a variety of technical challenges for automated handling, many of which are related to variations from batch to batch and/or strain to strain, such as: stickiness (oil/resin content), moisture content, mean particle size, and bulk density. Various techniques known to the industry have been employed or proposed in the past to mitigate the challenges. One known technique is freezing the product to reduce stickiness. This has the disadvantages of increasing operating costs, placing an environmental burden on operators, and the potential for product degradation.

[0005] Another technique is use of vibratory screening and classification to produce more consistent, homogenous feed product. Producers typically avoid vibratory screening where possible due to concerns about product attrition. Rich with active ingredients, trichomes are easily separated from the product by friction/impact. Vibratory screening can therefore lead to inconsistent properties of the end product in addition to increased buildup on contact surfaces. [0006] Existing technologies for processing and packaging of tobacco products have also been tested extensively, and have proven to be inapplicable due to the unique handling characteristics of cannabis.

Summaty of the Invention

[0007] To at least partially overcome some of the disadvantages of previously known methods and devices, in one aspect the present invention provides a system for delivering doses of ground cannabis comprising: a hopper for containing a bulk quantity of the ground cannabis, a screw auger feed mechanism for delivering the doses of the ground cannabis from the hopper, and a servo motor drive for driving the screw auger feed mechanism. The screw auger feed mechanism comprises an auger contained within a sleeve. The auger is supported at both ends to prevent floating of the auger in the sleeve. The screw auger feed mechanism also has a partially enclosed discharge port for directing the doses of the ground cannabis in a desired direction.

[0008] In preferred embodiments, the auger has a non-stick polymer coating; a pitch of about 3 tpi; and a leading face angle of about 90 degrees relative to a longitudinal axis of the auger. The auger may, for example, be formed from aluminum, stainless steel, or engineering plastic.

[0009] In some preferred embodiments, the system further includes a hopper agitator for agitating the ground cannabis in the hopper. The hopper agitator may, for example, comprise a wheel agitator that is located inside the hopper, and which has agitating blades that agitate the ground cannabis when the wheel agitator is rotated. The hopper agitator may also include, for example, at least one vertically extended agitator shaft that carries a plurality of finger blades, and which rotates about a vertical axis to agitate the ground cannabis in the hopper. [00010] Preferably, the auger has a minimal land width and is close fitting in the sleeve. For example, in some preferred embodiments the land width of the auger is no more than 0.075 inches, and the inner diameter of the sleeve is no more than 0.025 inches larger than the outer diameter of the auger. Preferably, the auger has a trailing face angle that is greater than 90 degrees relative to the longitudinal axis.

[00011] The invention preferably provides a compact module for metering and dosing small quantities of ground cannabis flower with high accuracy. This "micro-auger" system is preferably capable of operating at multiple cycles per second, while delivering accurate doses of product as small as ¼ gram or less.

[00012] A key application for the micro-auger system is to supplement existing filling systems by providing a secondary top-up function. Industry trends show the most common package weights for dry cannabis flower products are l.Og, 3.5g, and 7.0g. Automatic filling systems on the market today struggle to operate at rates sufficient to meet market demand while achieving repeatable accuracy better than 10% in many cases. With the high intrinsic value of the product, this giveaway product results in a significant parasitic cost to producers. [00013] In one preferred application, the primary filling system is set to a dosage weight slightly below the target weight. A micro-auger filling system is integrated downstream of the main system. After primary fill, the fill weight is measured on a load cell, and communicated to the micro-auger control system. The micro-auger then completes the fill process by delivering the required dose of product to bring the net fill weight up to target. This two-step process preferably significantly reduces overshoot compared to typical primary systems, without impeding the production rate. The system preferably allows primary systems to operate at a higher production rate without sacrificing accuracy in the final product. The end result is preferably lower giveaway and increased profitability.

[00014] In a variation, the system can be used to provide a bi-modal or multi-modal blend of product, where the primary filler doses a major percentage of the product weight as coarse product (chopped bud for example), and the target weight is achieved through addition of secondary fine product with the micro-auger system. This preferably results in tight control of the package weight, with the benefit of consistent presentation (appearance) of the product to the consumer.

[00015] Another key application for the system is the primary dosing system for joint/cone making systems that require small, highly accurate doses of flower product to control giveaway, appearance and physical integrity of the finished product. Typical pre-rolled cone style joints range from 0.35g to l.Og product weight.

[00016] The system can preferably improve a wide range of processing or packaging systems where increased accuracy of dry cannabis flower product dosing is of benefit. It is understood that the system could also be applied to other bulk materials with similar handling properties and processing requirements.

[00017] The system is preferably designed to deliver accurate, repeatable doses of ground cannabis flower in typical increments from ¼ gram up to 1.5 grams (but not limited to these values), and at a minimum production rate sufficient to meet or exceed the production rate of existing single-head filling systems (most struggle to achieve 40 containers per minute in practice, with normal rates of 20-25 containers per minute).

[00018] The system preferably has the following features: servo motor drive; small scale auger feed screw with non-stick polymer coating; bulk product hopper; and product agitation to ensure consistent feed.

[00019] In at least some preferred embodiments, the invention provides a compact self- contained feeder designed to deliver very accurate, small doses of ground/milled cannabis flower. Its preferred uses include supplementing commercial package filling systems with high accuracy secondary fill for tighter control of final product weight, or as a primary dosing system for cannabis joint manufacturing systems or small packages of cannabis flower (e.g. 1 gram pouches). The system preferably provides the benefit of improved accuracy and reduced product giveaway, and thus more net profit for producers.

[00020] Accordingly, in a first aspect, the present invention resides in a system for delivering doses of ground cannabis, comprising: a hopper for containing a bulk quantity of the ground cannabis; a screw auger feed mechanism for delivering the doses of the ground cannabis from the hopper; and a servo motor drive for driving the screw auger feed mechanism; wherein the screw auger feed mechanism comprises an auger that is received within a sleeve; wherein the sleeve has a first longitudinal end and a second longitudinal end; wherein the auger is supported at both the first longitudinal end and the second longitudinal end to prevent floating of the auger in the sleeve; and wherein the screw auger feed mechanism has a partially enclosed discharge port for directing the doses of the ground cannabis in a desired direction.

[00021] In a second aspect, the present invention resides in a system, which optionally incorporates one or more features of the first aspect, wherein the sleeve comprises: a cylindrical body; a first end housing member that is coupled to a first end of the cylindrical body; and a second end housing member that is coupled to a second end of the cylindrical body; wherein the first end housing member carries a first bushing that supports a first part of the auger at the first longitudinal end of the sleeve; wherein the second end housing member carries a second bushing that supports a second part of the auger at the second longitudinal end of the sleeve; wherein the sleeve is closed at the second longitudinal end to prevent the doses of the ground cannabis from being discharged longitudinally from the screw auger feed mechanism; wherein the second end housing member has a closed top portion that prevents the doses of the ground cannabis from being discharged upwardly from the screw auger feed mechanism; and wherein the second end housing member has an open bottom portion that defines the discharge port, and which discharges the doses of the ground cannabis downwardly from the screw auger feed mechanism.

[00022] In a third aspect, the present invention resides in a system, which optionally incorporates one or more features of any one or more of the first and second aspects, wherein the auger has a non-stick polymer coating; wherein the auger has a pitch of about 3 tpi; and wherein the auger has a leading face angle of about 90 degrees relative to a longitudinal axis of the auger.

[00023] In a fourth aspect, the present invention resides in a system, which optionally incorporates one or more features of any one or more of the first to third aspects, wherein the sleeve has an inner diameter and the auger has an outer diameter, the inner diameter of the sleeve being no more than 0.025 inches larger than the outer diameter of the auger; wherein the auger has a pitch of 1 tpi to 7.5 tpi; wherein the auger has a non-stick outer surface; and wherein the auger has a leading face angle of 75 to 105 degrees relative to a longitudinal axis of the auger.

[00024] In a fifth aspect, the present invention resides in a system, which optionally incorporates one or more features of any one or more of the first to fourth aspects, wherein the auger has a land width of no more than 0.075 inches; wherein the inner diameter of the sleeve is no more than 0.02 inches larger than the outer diameter of the auger; wherein the pitch of the auger is 2 tpi to 4 tpi; wherein the leading face angle of the auger is 85 to 95 degrees relative to the longitudinal axis of the auger; wherein the outer diameter of the auger is 0.5 to 1.25 inches; wherein the auger has a length of 5 to 12 inches; and wherein the auger has a trailing face angle that is greater than 90 degrees relative to the longitudinal axis of the auger. [00025] In a sixth aspect, the present invention resides in a system, which optionally incorporates one or more features of any one or more of the first to fifth aspects, wherein the pitch of the auger is about 3 tpi; wherein the leading face angle of the auger is about 90 degrees relative to the longitudinal axis of the auger; wherein the inner diameter of the sleeve is no more than 0.005 inches larger than the outer diameter of the auger; wherein the land width of the auger is no more than 0.06 inches; wherein the outer diameter of the auger is about 0.875 inches; wherein the auger has a thread depth of at least 0.1 inches; wherein the length of the auger is about 9.25 inches; and wherein the trailing face angle of the auger is about 117 degrees relative to the longitudinal axis of the auger.

[00026] In a seventh aspect, the present invention resides in a system, which optionally incorporates one or more features of any one or more of the first to sixth aspects, wherein the auger is constructed of a material that is compatible with a non-stick coating process, or that has inherent non-stick properties.

[00027] In an eighth aspect, the present invention resides in a system, which optionally incorporates one or more features of any one or more of the first to seventh aspects, wherein the auger is constructed of at least one of: stainless steel, aluminum, and engineering plastic. [00028] In a ninth aspect, the present invention resides in a system, which optionally incorporates one or more features of any one or more of the first to eighth aspects, wherein the auger is formed from aluminum; and wherein the non-stick polymer coating is a food- grade non-stick polymer coating.

[00029] In a tenth aspect, the present invention resides in a system, which optionally incorporates one or more features of any one or more of the first to ninth aspects, wherein the sleeve has an opening for receiving the ground cannabis from the hopper; wherein the opening has a planar first longitudinal side that lies in a first side plane; wherein the opening has a planar second longitudinal side that lies in a second side plane, the first longitudinal side being spaced from the second longitudinal side; wherein the first side plane and the second side plane are parallel to a center plane that contains a longitudinal axis of the sleeve and a center of the opening; wherein the first longitudinal side and the second longitudinal side each have an inner edge; and wherein the inner edge of the first longitudinal side is oriented at an angle of 90 degrees to 180 degrees relative to the inner edge of the second longitudinal side, the longitudinal axis of the sleeve forming the vertex of the angle.

[00030] In an eleventh aspect, the present invention resides in a system, which optionally incorporates one or more features of any one or more of the first to tenth aspects, further comprising a wheel agitator that is located inside the hopper, the wheel agitator having agitating blades that agitate the ground cannabis when the wheel agitator is rotated.

[00031] In a twelfth aspect, the present invention resides in a system, which optionally incorporates one or more features of any one or more of the first to eleventh aspects, further comprising a hopper agitation system for agitating the ground cannabis in the hopper, the hopper agitation system comprising: at least one vertically extended agitator shaft that carries a plurality of finger blades; and a wheel agitator that carries a plurality of agitating blades; wherein the agitator shaft rotates about a vertical axis to agitate the ground cannabis in the hopper; and wherein the wheel agitator rotates about a horizontal axis to agitate the ground cannabis in the hopper and to direct the ground cannabis in the hopper towards an upstream portion of the auger that is spaced from the discharge port. [00032] In a thirteenth aspect, the present invention resides in a system, which optionally incorporates one or more features of any one or more of the first to twelfth aspects, wherein the wheel agitator is formed from stainless steel; wherein the agitating blades extend from a face of the wheel agitator; wherein the wheel agitator has at least four of the agitating blades; wherein two of the agitating blades each have a linear shape when viewed facing towards the face of the wheel agitator; and wherein two of the agitating blades are each v-shaped when viewed facing towards the face of the wheel agitator.

[00033] In a fourteenth aspect, the present invention resides in a system, which optionally incorporates one or more features of any one or more of the first to thirteenth aspects, further comprising: a weighing device; and a rotary arm that carries a vessel; wherein the rotary arm is rotatable about a vertical axis to move the vessel between a fill station and a dump station; wherein the rotary arm is vertically movable along the vertical axis between a raised position and a lowered position; wherein the vessel is positioned below the discharge port for receiving the ground cannabis discharged from the screw auger feed mechanism when the vessel is at the fill station; wherein the vessel is positioned above the weighing device when the vessel is at the fill station; wherein the rotary arm has a carrying surface that engages with a catch surface of the vessel to support the vessel when the vessel is at the fill station and the rotary arm is at the raised position; wherein a bottom surface of the vessel engages with the weighing device when the vessel is at the fill station and the rotary arm is lowered from the raised position to the lowered position; wherein the catch surface of the vessel disengages from the carrying surface of the rotary arm when the vessel is at the fill station and the rotary arm is lowered from the raised position to the lowered position; and wherein the weighing device measures a weight of the ground cannabis received by the vessel from the screw auger feed mechanism when the vessel is at the fill station and the rotary arm is at the lowered position.

[00034] In a fifteenth aspect, the present invention resides in a method, which optionally incorporates one or more features of any one or more of the first to fourteenth aspects, the method comprising: providing the system in accordance with any one or more of the first to fourteenth aspects; placing the bulk quantity of the ground cannabis in the hopper; and using the servo motor drive to rotate the auger within the sleeve, to thereby deliver the doses of the ground cannabis from the discharge port.

[00035] In a sixteenth aspect, the present invention resides in a method, which optionally incorporates one or more features of any one or more of the first to fifteenth aspects, further comprising: controlling the servo motor drive to rotate the auger at a drive speed of about 2000 rotations per minute.

[00036] In a seventeenth aspect, the present invention resides in a method, which optionally incorporates one or more features of any one or more of the first to sixteenth aspects, further comprising: controlling the servo motor drive to deliver at least 150 of the doses of the ground cannabis per minute from the discharge port.

[00037] In an eighteenth aspect, the present invention resides in a method, which optionally incorporates one or more features of any one or more of the first to seventeenth aspects, further comprising: controlling the servo motor drive so that at least some of the doses of the ground cannabis have 1.5 grams or less of the ground cannabis.

[00038] In a nineteenth aspect, the present invention resides in a method, which optionally incorporates one or more features of any one or more of the first to eighteenth aspects, further comprising: controlling the servo motor drive so that at least some of the doses of the ground cannabis have 0.25 grams or less of the ground cannabis.

[00039] In a twentieth aspect, the present invention resides in a method, which optionally incorporates one or more features of any one or more of the first to nineteenth aspects, wherein the system is used as a secondary filling system, the method further comprising: using a primary filling system to dispense a primary dose of cannabis below a target weight; measuring a weight of the primary dose of cannabis; and using the secondary filling system to dispense a secondary dose of the ground cannabis; wherein the weight of the primary dose of cannabis is used as an input for controlling the secondary filling system so that a weight of the secondary dose of the ground cannabis dispensed from the secondary filling system, when combined with the weight of the primary dose of cannabis dispensed from the primary filling system, is equal to the target weight plus or minus 10%. [00040] In a twenty first aspect, the present invention resides in a method, which optionally incorporates one or more features of any one or more of the first to twentieth aspects, wherein the primary dose of cannabis comprises chopped cannabis flower.

[00041] In a twenty second aspect, the present invention resides in a method, which optionally incorporates one or more features of any one or more of the first to twenty first aspects, wherein the system is used as a dosing system for manufacturing pre-rolled cannabis joints.

[00042] In a twenty third aspect, the present invention resides in a method, which optionally incorporates one or more features of any one or more of the first to twenty second aspects, further comprising: weighing the ground cannabis that is discharged from the discharge port; and adjusting operation of the servo motor drive based on a weight of the ground cannabis that is discharged from the discharge port.

[00043] In a twenty fourth aspect, the present invention resides in a method, which optionally incorporates one or more features of any one or more of the first to twenty third aspects, further comprising: collecting the ground cannabis discharged from the discharge port in a vessel carried by a rotary arm; weighing the ground cannabis received by the vessel; rotating the rotary arm away from the discharge port; and discharging the ground cannabis from the vessel.

Brief Description of the Drawings

[00044] Further aspects and advantages of the invention will appear from the following description taken together with the accompanying drawings, in which:

[00045] Figure 1 is a schematic front view of a system for delivering doses of ground cannabis in accordance with a first embodiment of the present invention;

[00046] Figure 2 is a schematic side view of the system shown in Figure 1;

[00047] Figure 3 is a front view of a hopper of the system shown in Figure 1 ;

[00048] Figure 4 is a side view of the hopper shown in Figure 3;

[00049] Figure 5 is a side view of a sleeve assembly of the system shown in Figure 1; [00050] Figure 6 is a top view of a cylindrical body of the sleeve assembly shown in Figure 5;

[00051] Figure 7 is a side view of the cylindrical body shown in Figure 6;

[00052] Figure 8 is a cross-sectional view of the cylindrical body shown in Figure 6;

[00053] Figure 9 is a cross-sectional view the same as shown in Figure 8, but showing an optional variation in the size and configuration of an upper opening of the cylindrical body; [00054] Figure 10 is a cross-sectional view the same as shown in Figure 9, but showing a further optional variation in the size and configuration of the upper opening of the cylindrical body;

[00055] Figure 11 is a side view of an auger of the system shown in Figure 1;

[00056] Figure 12 is a side view of the auger shown in Figure 11, showing the auger coupled to a servo motor drive;

[00057] Figure 13 is a front view of a wheel agitator of the system shown in Figure 1; [00058] Figure 14 is a side view of the wheel agitator shown in Figure 13;

[00059] Figure 15 is a side view of an agitating blade of the wheel agitator shown in Figure

13;

[00060] Figure 16 is a top view of the agitating blade shown in Figure 15;

[00061] Figure 17 is a schematic front view of a check weighing system that is optionally included as part of the system shown in Figure 1 ;

[00062] Figure 18 is a schematic front view of the check weighing system shown in Figure

17, showing a rotary arm of the check weighing system at a lowered position and a vessel carried by the rotary arm at a fill station for receiving a dose of ground cannabis;

[00063] Figure 19 is a schematic front view of the check weighing system shown in Figure

18, showing the rotary arm at a raised position and the vessel with the dose of ground cannabis at the fill station;

[00064] Figure 20 is a schematic front view of the check weighing system shown in Figure

19, showing the rotary arm at the raised position and rotated 180 degrees about a vertical axis so that the vessel with the dose of ground cannabis is located at a dump station; [00065] Figure 21 is a schematic front view of the check weighing system shown in Figure 20, showing the rotary arm at the lowered position, the vessel at the dump station rotated about a horizontal axis to discharge the dose of ground cannabis into a funnel, and a second vessel carried by the rotary arm located at the fill station for receiving a second dose of ground cannabis;

[00066] Figure 22 is a schematic top view of the check weighing system shown in Figure 20, depicting the rotation of the rotary arm about the vertical axis;

[00067] Figure 23 is a schematic front view of a system for delivering doses of ground cannabis in accordance with a second embodiment of the present invention;

[00068] Figure 24 is a front view of a wheel agitator of the system shown in Figure 23; and

[00069] Figure 25 is a side view of the wheel agitator shown in Figure 24.

Detailed Description of the Drawings

[00070] Figures 1 to 16 show a system 10 for delivering doses of ground cannabis 12 in accordance with a first embodiment of the present invention. The system 10 includes a hopper 14, a hopper agitation system 16, a screw auger feed mechanism 18, and a servo motor drive 20.

[00071] The hopper 14 is a container for containing a bulk quantity of the ground cannabis 12. The hopper 14 may be made from any suitable material, including for example metal or plastic. As can be seen in Figures 3 and 4, the hopper 14 has a generally rectangular upper portion 22, a tapered intermediate portion 24 where the width of the hopper 14 decreases, and a lower feeding portion 26. The lower portion 26 has a left side mounting ring 28 and a right side mounting ring 30, each of which has a central opening 32 for receiving the screw auger feed mechanism 18. The hopper has a height 34, a width 36, and a depth 38. In the embodiment shown in Figures 3 and 4, the height 34 is about 18 inches, the depth 38 is about 2.95 inches, and the width 36 is about 7.125 inches (as measured at the upper portion 22), though any other suitable dimensions could be used instead.

[00072] The hopper agitation system 16 is preferably provided to agitate the ground cannabis 12 in the hopper 14 so as to prevent or reduce bridging and to provide a consistent bulk density. As can be seen in Figures 1 and 2, the hopper agitation system 16 includes three agitator shafts 40 that extend vertically through the upper portion 22 of the hopper 14, an agitator shaft drive system 42, a wheel agitator 44 mounted in the intermediate portion 24 of the hopper 14 and partially extending into the lower portion 26, and a wheel agitator drive system 46.

[00073] Referring to Figures 1 and 2, each of the agitator shafts 40 has six pairs of finger blades 48 that extend downwardly and outwardly from the shafts 40. The two finger blades 48 in each pair lie in a common plane that is oriented 90 degrees relative to the plane containing the vertically adjacent pair or pairs of finger blades 48. The finger blades 48 on the central agitator shaft 40 are staggered vertically relative to the finger blades 48 on the two side agitator shafts 40.

[00074] In the embodiment shown in Figures 1 and 2, the agitator shaft drive system 42 includes two pneumatic motors 50 that each rotate one of the side agitator shafts 40 about a respective vertical axis, and a belt drive 52 that is used to rotate the center agitator shaft 40 about its vertical axis. Any other suitable arrangement for rotating the agitator shafts 40 could be used instead. As the agitator shafts 40 rotate, the finger blades 48 agitate the ground cannabis 12 in the hopper 14 and help to prevent or reduce bridging and maintain a consistent bulk density.

[00075] The wheel agitator 44 is best shown in Figures 13 and 14 as having a circular face 54, a central channel forming body 56 that extends through the center of the circular face 54, and four agitating blades 58A, 58B, 58C, 58D that extend forwardly from the circular face 54. Each of the agitating blades 58A, 58B, 58C, 58D has a different shape, with two of the agitating blades 58A, 58B appearing linear when viewed facing towards the circular face 54 as shown in Figure 13, and the remaining two agitating blades 58C, 58D appearing v-shaped when viewed facing towards the circular face 54.

[00076] A first one of the agitating blades 58A is shown in more detail in Figures 15 and 16. The first agitating blade 58A has a base portion 60 where the first agitating blade 58A connects to the circular face 54, the first agitating blade 58A extending forwardly from the base portion 60 to a partially inclined top surface 62. The top surface 62 has a lower comer 64 and an upper comer 66, the lower comer 64 being closer to the base portion 60 than the upper comer 66 is to the base portion 60. In the embodiment shown, the distance 68 from the base portion 60 to the lower comer 64 is about 0.581 inches; the distance 70 from the base portion 60 to the upper comer 66 is about 0.75 inches; and the length 72 of the first agitating blade 58A is about 0.712 inches. Other suitable dimensions could also be used.

[00077] The second agitating blade 58B has a generally similar shape to the first agitating blade 58 A, but has a flat top surface 62 instead of a partially inclined top surface 62. The top surface 62 of the second agitating blade 58B may, for example, extend about 0.5 to 0.75 inches from the circular face 54, and the second agitating blade 58B could have a length of about 0.712 inches, though any other suitable dimensions could be used.

[00078] The third agitating blade 58C has a first linear portion 74 and a second linear portion 76 that are connected together and angled relative to one another to form a v-like shape, with the open end of the v facing away from the central channel forming body 56. The angle between the first linear portion 74 and the second linear portion 76 is preferably greater than 90 degrees and less than 180 degrees. In the embodiment shown, the angle is about 135 degrees. The first linear portion 74 has a shape generally similar to the first agitating blade 58A and the second linear portion 76 has a shape generally similar to the second agitating blade 58B. Each of the first linear portion 74 and the second linear portion 76 may, for example, have a length of about 0.791 inches.

[00079] The fourth agitating blade 58D has a generally similar shape to the third agitating blade 58C, except that the first linear portion 74 and the second linear portion 76 both have a generally similar shape to the second agitating blade 58B.

[00080] The agitating blades 58 A, 58B, 58C, 58D are arranged on the circular face 54 so as to partially define a square when viewed facing towards the circular face 54, with the first agitating blade 58A extending from a first comer of the square towards a second comer of the square along a first side of the square; the first linear portion 74 of the fourth agitating blade 58D extending from the second comer of the square towards a third comer of the square along a second side of the square; the first linear portion 74 of the third agitating blade 58C extending from the third comer of the square towards a fourth comer of the square along a third side of the square; and the second agitating blade 58B extending from the fourth comer of the square towards the first comer of the square along a fourth side of the square.

[00081] The wheel agitator drive system 46 is shown in Figure 2 as including a motor 78 with a shaft coupling 80 that extends through the central channel forming body 56 of the wheel agitator 44. The wheel agitator drive system 46 rotates the wheel agitator 44 about a horizontal axis so that the agitator blades 58A, 58B, 58C, 58C agitate the ground cannabis 12 in the intermediate portion 24 and the lower portion 26 of the hopper 12. Preferably, the wheel agitator 44 is rotated so as to direct the ground cannabis 12 towards a rear or upstream portion of the screw auger feed mechanism 18.

[00082] The screw auger feed mechanism 18 includes a sleeve or sleeve assembly 82 and an auger 84. The sleeve assembly 82 is shown in Figure 5, and includes a cylindrical body 86, a first end housing member 88 attached to a first end 90 of the cylindrical body 86, a first bushing 92 supported by the first end housing member 88, a second end housing member 94 attached to a second end 96 of the cylindrical body 86, and a second bushing 98 supported by the second end housing member 94.

[00083] As shown in Figures 6 to 8, the cylindrical body 86 has a cylindrical wall 100 that extends concentrically about a sleeve axis 102 from the first open end 90 to the second open end 96. In the embodiment shown, the cylindrical body 86 has a length 104 of about 6.82 inches, an outer diameter 106 of about 1 inch, and an inner diameter 108 of about 0.875 inches, although any suitable dimensions could be selected.

[00084] The sleeve 82 has an opening 110 in the upper surface of the cylindrical wall 100 that extends longitudinally for much of the length 104 of the cylindrical body 86. As best shown in Figure 8, the opening 110 has a planar first longitudinal side 112 that lies in a first side plane 114 and a planar second longitudinal side 116 that lies in a second side plane 118, the first longitudinal side 112 being spaced from the second longitudinal side 116. The first side plane 114 and the second side plane 118 are both parallel to a center plane 120 that extends through both the sleeve axis 102 and the center of the opening 110.

[00085] This configuration of the first longitudinal side 112 and the second longitudinal side 116 causes the first longitudinal side 112 and the second longitudinal side 116 to each have a sharp upper edge 122. The sharp upper edges 122 preferably encourage knifing of the ground cannabis 12 as the ground cannabis 12 enters the opening 110 of the sleeve 82, thereby minimizing compression of the ground cannabis 12.

[00086] As shown in Figures 8 to 10, the first longitudinal side 112 and the second longitudinal side 116 are oriented relative to each other at an angle 124, with the sleeve axis 102 forming the vertex of the angle 124. The angle 124 is preferably 90 degrees to 180 degrees, and is most preferably at least 135 degrees, which has been shown in at least some embodiments of the invention to improve weighment consistency and provide better resistance to bridging/clogging. The angle 124 is measured from an inner edge 126 of the first longitudinal side 112 and an inner edge 126 of the second longitudinal side 116. Figure 8 shows the opening 110 in which the angle 124 is 180 degrees; Figure 9 shows the opening 110 in which the angle 124 is 135 degrees; and Figure 10 shows the opening in which the angle 124 is 90 degrees.

[00087] Returning to Figure 5, the first end housing member 88 is a cap-like structure that attaches to the first end 90 of the cylindrical body 86. The second end housing member 94 attaches to the second end 96 of the cylindrical body 86, and has a generally cylindrical form that extends from the second end 96 of the cylindrical body 86 along the sleeve axis 102. The second end housing member 94 has a closed longitudinal end 128 that prevents the ground cannabis 12 from being discharged longitudinally from the screw auger feed mechanism 18; a closed top portion 130 that prevents the ground cannabis 12 from being discharged upwardly from the screw auger feed mechanism 18; and an open bottom portion 132 that defines a discharge port 134 for discharging the ground cannabis 12 downwardly from the screw auger feed mechanism 18. The closed longitudinal end 128 and the closed top portion 130 of the second end housing member 94 causes the discharge port 134 to be partially enclosed, so as to direct the ground cannabis 12 in the desired direction.

[00088] The first end housing member 88 attaches to the left side mounting ring 28 of the hopper 14, and the second end housing member 94 attaches to the right side mounting ring 30 of the hopper 14, with the cylindrical body 86 extending horizontally between the first end housing member 88 and the second end housing member 94 through the lower portion 26 of the hopper 14.

[00089] The auger 84 is shown in Figures 11 and 12, and extends from a first end 136 to a second end 138 along a longitudinal axis 140. The auger 84 has a first extension portion 142, a threaded portion 144, a second extension portion 146, and a terminal portion 148. The first extension portion 142 extends from the first end 136 to the threaded portion 144; the threaded portion 144 extends between the first extension portion 142 and the second extension portion 146; the second extension portion 146 extends between the threaded portion 144 and the terminal portion 144; and the terminal portion 144 extends from the second extension portion 146 to the second end 138.

[00090] The threaded portion 144 has a cylindrical core 150 and a thread 152 that extends radially outwardly from the cylindrical core 150 to form a spiral that extends from an upstream end 154 to a downstream end 156 of the threaded portion 144. The thread 152 has a trailing face 158 that faces towards the upstream end 154, a leading face 160 that faces towards the downstream end 156, and an outer face 162 that connects the trailing face 158 to the leading face 160 and that faces radially outwardly away from the longitudinal axis 140. [00091] In the embodiment shown Figures 11 and 12, the cylindrical core 150 has a diameter 164 of about 0.657 inches; the thread 152 has an outer diameter 166 of about 0.875 inches; the thread 152 has a depth 250 of about 0.114 inches; and the outer face 162 has a width 168 of about 0.058 inches. The width 168 of the outer face 162 is also referred to herein as the land width 168.

[00092] As shown in Figure 12, the trailing face 158 of the thread 152 extends radially outwardly from the cylindrical core 150 at a trailing face angle 170, and the leading face 160 of the thread 152 extends radially outwardly from the cylindrical core 150 at a leading face angle 172. In the embodiment shown, the trailing face angle 170 is about 117 degrees and the leading face angle 172 is about 90 degrees. The trailing face angle 170 and the leading face angle 172 may be measured relative to either the outer surface of the cylindrical core 150 or the longitudinal axis 140 of the auger 84. [00093] The first extension portion 142 of the auger 84 extends from the upstream end 154 of the threaded portion 144 to the first end 136 of the auger 84 and has a reduced diameter 174 as compared to the diameter 164 of the cylindrical core 150. The second extension portion 146 extends from the downstream end 156 of the threaded portion 148 towards the second end 138 of the auger 84 and also has the reduced diameter 174 as compared to the diameter 164 of the cylindrical core 150. In the embodiment shown, the diameter 174 of the first extension portion 142 and the second extension portion 146 is about 0.312 inches. The terminal portion 144 extends from the second extension portion 146 to the second end 138 of the auger 84 and has a fiirther reduced diameter 176 as compared to the diameter 174 of the second extension portion 146. The diameter 176 of the terminal portion 144 is only slightly smaller than the diameter 174 of the second extension portion 146, and may for example be about 0.3 inches. In the embodiment shown in Figures 11 and 12, the overall length 178 of the auger 84 from the first end 136 to the second end 138 is about 9.25 inches. Other suitable dimensions and configurations of the auger 84 could also be used.

[00094] As shown in Figure 12, the servo motor drive 20 attaches to the first end 136 of the auger 84 via a shaft coupling 180. The shaft coupling 180 may, for example, comprise a flex,

3 pin, or other suitable coupling type. A controller, not shown, controls the servo motor drive 20 to rotate the auger 84 about the longitudinal axis 140.

[00095] As shown schematically in Figure 1, when the screw auger feed mechanism 18 is fully assembled, the threaded portion 144 of the auger 84 is received within an inner cavity 182 of the sleeve 82, with the first extension portion 142 of the auger 84 being supported by and extending through the first bushing 92 at a first longitudinal end 252 of the sleeve 82 for engagement with the shaft coupling 180, and with the terminal portion 144 of the auger 84 being supported by the second bushing 98 at a second longitudinal end 254 of the sleeve 82. Having both the first extension portion 142 and the terminal portion 144 of the auger 84 being supported by bushings 92, 98 at each end of the sleeve assembly 82 helps to prevent floating of the auger 84 in the sleeve 82. In other words, the bushings 92, 98 help to keep the longitudinal axis 140 of the auger 84 aligned with the sleeve axis 102 of the sleeve 82. [00096] During operation of the system 10, the agitating shafts 40 rotate about their respective vertical axes to agitate the ground cannabis 12 in the manner as described above. The wheel agitator 44 rotates about its horizontal axis to further agitate the ground cannabis 12 immediately adjacent to the screw auger feed mechanism 18. In the embodiment shown in Figure 1, the wheel agitator 44 preferably rotates in a counterclockwise direction so that the agitating blades 58A, 58B, 58C, 58D direct the ground cannabis 12 towards the upstream end 154 of the threaded portion 144 of the auger 84.

[00097] The ground cannabis 12 enters the inner cavity 182 of the sleeve 82 via the opening 110, and is directed towards the downstream end 156 of the auger 84 by the leading face 160 of the thread 152 as the auger 84 is rotated about its longitudinal axis 140. When the ground cannabis 12 reaches the downstream end 156 of the auger 84, it is discharged downwardly from the screw auger feed mechanism 18 via the discharge port 134.

[00098] The servo motor drive 20 is preferably controlled to rapidly and accurately dispense a series doses of the ground cannabis 12 from the discharge port 134 of the screw auger feed mechanism 18, by rapidly rotating the auger 84 to dispense a dose of the ground cannabis 12, and then pausing briefly while the dose is moved away from the discharge port 134, and then rapidly rotating the auger 84 again to dispense the next dose of the ground cannabis 12. In some embodiments of the invention, the servo motor drive 20 could be controlled to dispense the same amount of ground cannabis 12 in each dose that is dispensed, for example if the system is being used as a primary filling system for pre-rolled joints. [00099] Alternatively, the servo motor drive 20 could be controlled to dispense a varying quantity of the ground cannabis 12 in each dose. For example, the system 10 could be used as a secondary filling system in which the amount of ground cannabis 12 that is dispensed in each dose depends on the amount of cannabis that was dispensed by the primary filling system. The primary filling system may, for example, be configured to dispense a primary dose of chopped cannabis into a container or package, with the primary dose being selected to be less than the target weight of the container or package. The primary filling system is preferably configured to dispense the primary dose rapidly, even if this leads to significant variability in the amount of cannabis that is dispensed in each primary dose. The primary dose is then preferably weighed to determine the amount of cannabis that was dispensed by the primary filling system, and this information is then used to control the servo motor drive 20 to dispense a secondary dose of the ground cannabis 12 into the container or package, the quantity of ground cannabis 12 in the secondary dose being selected so that the combined weight of the primary dose and the secondary dose is equal to the target weight, optionally with some preselected acceptable level of variance such as plus or minus 10%.

[000100] Reference is now made to Figures 17 to 22, which schematically depict a check weighing system 184 that is optionally incorporated into the system 10 shown in Figures 1 to 16. The check weighing system 184 includes a rotary arm or rotary member 186, an arm support mechanism 188, and a weighing device 190. The rotary arm 186 is rotatable about a vertical axis 192, and has a first arm extension 194 that extends horizontally from the vertical axis 192 in a first direction, and a second arm extension 196 that extends horizontally from the vertical axis 192 in a second direction that is oriented 180 degrees relative to the first direction.

[000101] The first arm extension 194 carries a first rotary actuator 198 that is connected to a first vessel engagement ring 200. The vessel engagement ring 200 has a central channel 202, a first carrying surface 204 that extends radially outwardly from a first open end 206 of the central channel 202, and a second carrying surface 208 that extends radially outwardly from a second open end 210 of the central channel 202.

[000102] The first vessel engagement ring 200 is rotatable by the first rotary actuator 198 about a horizontal axis between an upright position, as shown in Figure 17, and a discharge position, as shown in Figure 21. When in the upright position as shown in Figure 17, the first carrying surface 204 faces upwards and the second carrying surface 208 faces downwards. When in the discharge position shown in Figure 21, the first carrying surface 204 faces downwards and the second carrying face 208 faces upwards.

[000103] The first vessel engagement ring 200 carries a first vessel 212. The first vessel 212 extends through the central channel 202 of the first vessel engagement ring 200 and has an inner chamber 214 with an open top end 216 and a closed bottom end 218; a first catch ring 220 that extends radially outwardly adjacent to the open top end 216; and a second catch ring 222 that extends radially outwardly adjacent to the closed bottom end 218. The first catch ring 220 has a first catch surface 224 that faces towards the first carrying surface 204, and the second catch ring 222 has a second catch surface 226 that faces towards the second carrying surface 208.

[000104] When the first vessel engagement ring 200 is at the upright position as shown in Figure 17, the first carrying surface 204 engages with the first catch surface 224 to support the first vessel 212, and the open top end 216 of the first vessel 212 faces upwardly. When the first vessel engagement ring 200 is at the discharge position as shown in Figure 21, the second carrying surface 208 engages with the second catch surface 226 to support the first vessel 212, and the open top end 2216 of the first vessel 212 faces downwardly.

[000105] The second arm extension 196 carries a second rotary actuator 228 that is connected to a second vessel engagement ring 230, and the second vessel engagement ring 230 carries a second vessel 232. The structure and function of the second rotary actuator 228 is identical to the structure and function of the first rotary actuator 198; the structure and function of the second vessel engagement ring 230 is identical to the structure and function of the first vessel engagement ring 200; and the structure and function of the second vessel 232 is identical to the structure and function of the first vessel 212.

[000106] The arm support mechanism 188 includes a first linear actuator 234, a second linear actuator 236, and a third rotary actuator 238. The third rotary actuator 238 supports the rotary arm 186 and is operable to rotate the rotary arm 186 about the vertical axis 192 to move the first vessel 212 and the second vessel 232 between a fill station 240 and a dump or discharge station 242. In Figure 17, the first vessel 212 is located at the fill station 240 and the second vessel 232 is located at the dump station 242. When located at the fill station 240, the vessel 212, 232 is positioned below the discharge port 134 of the screw auger feed mechanism 18 and above the weighing device 190. When located at the dump station 242, the vessel 212, 232 is positioned above a funnel member 244.

[000107] The third rotary actuator 238 is supported by the first linear actuator 234 and the second linear actuator 236. The first linear actuator 234 and the second linear actuator 236 are operable to raise and lower the third rotary actuator 238 and the rotary arm 186 between a lowered position, as shown in Figure 18, and a raised position, as shown in Figure 19. For ease of reference, Figures 18 to 21 show two dotted lines 256 and 258 and a marker 260 on the first linear actuator 234. When at the lowered position, the marker 260 is aligned with line 256, and when at the raised position, the marker 260 is aligned with line 258.

[000108] The weighing device 190 is located at the fill station 240, and is used to weigh the ground cannabis 12 that is discharged into the vessels 212, 232 from the discharge port 134. The weighing device 190 may for example be a load cell, though any suitable device for measuring weight could be used.

[000109] The manner in which the check weighing system 184 is operated will now be described with reference to Figures 18 to 21. As shown in Figure 18, the rotary arm 186 is initially at the lowered position, with the first vessel 212 located at the fill station 240 and the second vessel 233 located at the dump station 242. When the rotary arm 186 is at the lowered position, a bottom surface 246 of the first vessel 212 engages with the weighing device 190, which causes the first catch surface 224 to disengage from the first carrying surface 204, such that the weight of the first vessel 212 rests solely on the weighing device 190.

[000110] While at the position shown in Figure 18, a dose of the ground cannabis 12 is discharged from the discharge port 134 into the open top end 216 of the first vessel 212, such that the dose of ground cannabis 12 comes to rest at the closed bottom end 218 of the first vessel 212 and the weight of the dose of ground cannabis 12 is measured by the weighing device 190. In some preferred embodiments, the weighing device 190 measures the weight of the ground cannabis 12 as it is being discharged into the first vessel 212, and the real time weight measurements are used as an input for controlling the servo motor drive 20 to improve the accuracy of the screw auger feed mechanism 18 in dispensing the desired dose of ground cannabis 12. Alternatively, the weighing device 190 could be configured to measure the weight of the dose of ground cannabis 12 only after the entire dose has been dispensed into the first vessel 212, with the weight measurement being used for example for quality control. If the weight measurement indicates that the dose of ground cannabis 12 unacceptably deviates from the intended weight, the dose can for example be flagged so that it can be discarded or returned to the hopper 14 later in the process. Optionally, the check weighing system 184 could include a discard station where flagged doses of the ground cannabis 12 are discarded.

[000111] Referring now to Figure 19, after the dose of ground cannabis 12 has been discharged into the first vessel 212 and weighed, the first and second linear actuators 234, 236 raise the rotary arm 186 up from the lowered position to the raised position. This causes the first carrying surface 204 of the first vessel engagement ring 200 to engage with the first catch surface 224 of the first vessel 212, which raises the first vessel 212 up and out of engagement with the weighing device 190.

[000112] Referring to Figure 20, the third rotary actuator 238 then rotates the rotary arm 186 180 degrees about the vertical axis 192, so that the first vessel 212 is now located at the dump station 242 and the second vessel 232 is now located at the fill station 240.

[000113] Referring to Figure 21, the first and second linear actuators 234, 236 then lower the rotary arm 186 from the raised position down to the lowered position, so that the second vessel 232 comes to rest on the weighing device 190, and a subsequent dose of the ground cannabis 12 is dispensed from the discharge port 134 into the second vessel 232. Simultaneously, the first rotary actuator 198 rotates the first vessel engagement ring 200 from the upright position to the discharge position, so that the dose of ground cannabis 12 in the first vessel 212 is discharged from the first vessel 212 into the funnel member 244. The dose of ground cannabis 12 is carried by the funnel member 244 to the next stage of processing/packaging.

[000114] After the dose of ground cannabis 12 is discharged from the first vessel 212, the first rotary actuator 198 returns the first vessel engagement ring 200 to the upright position; the rotary arm 186 is returned to the raised position; and the rotary arm 186 is rotated another 180 degrees about the vertical axis 192 so that the dose of ground cannabis 12 in the second vessel 232 can be discharged at the dump station 242 and a further dose of ground cannabis 12 can be collected and weighed in the first vessel 212 at the fill station 240. This cycle can then be repeated indefinitely, with each dose of ground cannabis 12 being weighed by the check weighing system 184 before entering the next stage of processing and/or packaging. [000115] Reference is now made to Figures 23 to 25, which show a system 10 for delivering doses of ground cannabis 12 in accordance with a second embodiment of the present invention. Like numerals are used to denote like components.

[000116] The system 10 shown in Figures 23 to 25 is identical to the system 10 shown in Figures 1 to 22, except for the hopper agitation system 16. In the embodiment shown in Figures 23 to 25, the hopper agitation system 16 does not include any agitator shafts 40, and the wheel agitator 44 has a different construction.

[000117] As shown in Figure 24, the wheel agitator 44 in accordance with the second embodiment of the invention has a toothed circumferential surface 248. The toothed circumferential surface 248 is configured to extend through the opening 110 in the sleeve 82 so as to engage with the thread 152 of the auger 84. When the auger 84 is rotated by the servo motor drive 20, the thread 152 pushes against the toothed circumferential surface 248, which causes the wheel agitator 44 to rotate. The wheel agitator 44 therefore does not require a separate wheel agitator drive system 46, and is instead indirectly driven by the servo motor drive 20 via the auger 44.

[000118] The agitating blades 58 in the second embodiment of the invention also have a different structure from the agitating blades 58A, 58B, 58C, 58D in the first embodiment of the invention. In the second embodiment as shown in Figure 24, each of the agitating blades 58 has a linear shape when viewed facing towards the circular face 54 of the wheel agitator 44. The agitating blades 58 in the second embodiment of the invention may, for example, have the same structure as the second agitating blade 58B in the first embodiment.

Design and Development

[000119] During design and development of the present invention, a small (1 inch outer diameter) commercial auger 84 designed for granular food products was tested, using a stepper motor drive. The commercial auger 84 was constructed with an ultra high molecular weight polyethylene (UHMW) screw over an aluminum core. It was found that the pitch (helix) was too high, resulting in inconsistent results. [000120] The commercial auger 84 had no bearings, it was free floating in the sleeve 82.

The discharge port 134 was not shrouded, allowing product spillage. The discharge port 134 was also too small for ground cannabis flower 12, and was designed for dry granular product such as coffee.

[000121] A new auger 84 was fabricated having a lower helix angle (pitch) with the same materials. The new auger 84 was found to have improved performance, but still inconsistent. [000122] It was determined that the typical design of the auger system with no supporting bearing surface allowed the screw to float and/or deflect in the screw cavity, resulting in variances.

[000123] The following improvements were made:

A close fitting sleeve 82 to contain the auger 84 and provide consistent volume per revolution.

Bushing/bearing supports 92, 98 at both ends of the auger 84 to prevent floating or movement in the sleeve 82.

Partially enclosed discharge port 134 in the auger sleeve 82, designed to prevent product from being thrown outwards due to the rotational forces. The design contains and guides the product to the outlet, preventing spillage and waste.

Replacement of the stepper motor drive with servo drive 20. The variable torque available from the servo drive 20 in response to shaft load, eliminated deviation caused by continual fluctuations in the torque required by the auger 84.

[000124] Testing of the above changes showed good accuracy and consistency. However, improvements were still possible to reduce or eliminate the buildup of product and the resulting degradation in performance over repeated cycles.

[000125] In one preferred design configuration tested, a screw with pitch of 3tpi, straight leading wall and minimal land (thickness of flat spot on peak of helix) was used to produce the reported result.

[000126] Change to an aluminum auger body permitted application of a food-grade nonstick polymer coating, resulting in zero buildup over the test period. Other structural materials compatible with such coatings may be used. [000127] In each of three separate initial tests, 51b of product were cycled through the system 10, with a setpoint of 0.5g under normal ambient conditions.

[000128] Each test resulted in 100% weighments within 10%/0.05g of the target.

[000129] Drive speed during testing was 2000 rotations per minute, producing the 0.5g weighments in a fraction of a second. Preferably, 4-5 cycles per second (i.e. 4-5 individual weighments) can be achieved while maintaining tested accuracy. This demonstrates that the operating rate of the system 10 is capable of supporting production rates of 150-200 weighments/products/parts/containers per minute or greater while maintaining the production cost benefits. Data indicates that 40-42 containers per minute is the maximum observed rate in the field, to date, for conventional single head filling systems while maintaining minimum +- 10% accuracy as required.

[000130] One preferred configuration of the system 10 is as follows:

A hopper 14 for bulk, pre-ground product, plastic or metallic.

Servo motor drive 20 for the auger 84. For best results the drive system must be capable of providing sufficient torque to overcome variations in shaft load caused by momentary accumulation of product, and ultimately to drive all product to the discharge point.

A screw auger feed mechanism 18 with the following features:

- Close fitting outer sleeve 82 (plastic or metal).

- Bushing 92, 98 or bearing support at both ends.

- Discharge port 134 in sleeve 82, designed to allow product to flow in desired direction only and contain any potential spillage.

- Aluminum auger 84 body, or other material compatible with non-stick coating processes.

- Auger 84 screw surfaces coated with non-stick polymer coating, preferably food- grade (e.g. General Magnaplate Lectrofluor® 605)

- Pitch, face angle and land of the helix tailored for cannabis handling - one preferred design as tested uses 3 tpi, straight leading wall 160 and minimum land width 168. Optional slave driven hopper agitator 16 for the bulk product. [000131] Further improvements made to the system 10 include the following:

[000132] The opening 110 in the auger sleeve 82 was modified to allow better product flow. The larger product inlet port or opening 110 was designed to have sharp edges to encourage knifing of the product and minimize compression into the thread cavity. Openings 110 with included angles of 90 degrees up to 180 degrees were tested, with openings of 135 degrees and higher being especially preferred, and showing improvement in weighment consistency and better resistance to bridging/clogging.

[000133] To prevent bridging issues, a three shaft 40 mixing agitator system was designed to constantly break up product bridging. The shafts 40 are optionally driven by means of 2 rotary air cylinders or pneumatic motors 50 and a timing belt and pulleys or belt drive 60 driving the center shaft 40.

[000134] To reduce issues of wear on the wheel agitator 44 a stainless steel wheel agitator 44 was designed. The wheel agitator 44 is preferably driven by an independent DC motor on each hopper 14. The hoppers 14 preferably have the wheel agitator 44 installed with a stainless steel shaft with a yoke style drive coupling. The motors preferably turn the wheel agitator 44 towards the back of the screw or auger 84 so that the screw or auger 84 is adequately primed at all times.

[000135] The original hopper agitator system 16 tested consisted of a simple wheel agitator 44 operating close to and parallel with the auger 84, and slave driven by the auger 84. While reasonably effective, further testing revealed that the wide variety of bulk cannabis properties and environmental conditions encountered in typical operation required more thorough mixing and agitation of the hopper contents to provide consistent flow and bulk density. Subsequent designs feature modifications to the blade 58 angle and location, additional blades 58, and a separate drive mechanism 46. In addition, various stirring mechanisms for the upper level bulk hopper contents were added to break up any clumps and to encourage free flow.

For one preferred hopper 14 design currently in use, a 3-shaft 40 stirring mechanism as illustrated in Figure 1 was found to be effective at maintaining free flow of the contents. The current design uses pneumatic motors 50 to drive the agitator shafts 40, and a servo motor 78 to drive the agitator wheel 44, however other means are possible. [000136] A further preferred configuration of the system 10 is as follows:

A hopper 14 for bulk, pre-ground product, plastic or metallic in construction

Servo motor drive 20 for the auger 84. For best results, the drive system must be capable of providing sufficient torque to overcome variations in shaft load caused by momentary accumulation of product, and ultimately to drive all product to the discharge point.

A screw auger feed mechanism 18 with the following features:

Close fitting outer sleeve 82 (plastic or metal) with optional non-stick polymer coating.

Bushing 92, 98 or bearing support at both ends.

Inlet port or opening 110 with square cut (no radius) edges and with included opening angles of 90 to 180 degrees.

Discharge port 134 in sleeve 82, designed to allow product to flow in desired direction only and contain any potential spillage.

Auger screw 84 constructed of stainless steel, aluminum, engineering plastic, or other metallic or non-metallic structural material.

Auger screw 84 constructed of material compatible with non-stick coating processes, or with inherent non-stick properties.

Auger screw 84 surfaces coated with non-stick polymer coating, preferably food- grade. One example successfully tested is General Magnaplate Lectrofluor® 605.

Pitch, face angle and land of the helix tailored for cannabis handling - one preferred design as tested uses 3 tpi, straight leading wall 160 and minimum land width 168.

Pitch angle from ltpi to 7.5tpi.

Minimum practical land width 168 (based on material properties) for reduced contact area to outer sleeve 82.

Leading face angle 172 (relative to longitudinal axis 140) from 75 to 105 degrees.

Thread depth 250 selected, based on material properties, to provide maximum free volume while maintaining adequate mechanical rigidity. A hopper agitator system 16 to agitate the bulk product to avoid clumping and inconsistent bulk density. May be equipped with a slave-drive, electrical, or pneumatic drive system 42. System 16 can use an agitator wheel 44, stirring shafts 40, or a combination of these devices as required by the dimensions and proportions of the bulk material hopper 14.

[000137] Optionally, the system 10 is also equipped with “filler feedback” software to receive live weight feedback from a weighing system and adjust the dosing parameters during operation to maintain a high level of accuracy despite typical variations in operating conditions.

[000138] Optionally, the system 10 is equipped with an auxiliary fill-dump station to provide secondary weight verification. As opposed to depositing directly into the package/product, in this system 10 the auger 84 deposits a dose of product into an intermediate vessel 212, 232 (e.g. a small stainless steel cup) which is equipped with a load cell 190 for secondary weight verification. The cup 212, 232 is supported on a horizontal arm 186 mounted to a rotary actuator 238, and the complete rotary arm 186/cup assembly is able to be raised and lowered for cycling via an additional actuator 234, 236. Once a dose of product has been deposited into the cup 212, 232, and the load cell 190 has completed the weighing operation, the assembly is then raised to lift the cup 212, 232 clear of the load cell 190, then the rotary arm 186 indexes to the next position, and the next cup 212, 232 filled. [000139] At minimum, the rotary arm 186 assembly indexes to two stations, typically 180 degrees apart, for filling and for dumping. Additional stations may be incorporated for secondary operations, e.g. rejecting off-spec product doses at a separate station.

[000140] The fill-dump system preferably employs a symmetrical arm 186 mounted on a rotary cylinder 238 that provides the ability to index the table from station to station as required. In a simple embodiment, the arm 186 rotates 180 degrees in the horizontal plane each cycle. Each end of the arm 186 is equipped with a rotary cylinder 198, 228 to which is mounted a holding ring 200, 230 (or alternate clamp mechanism) that captures a cup 212, 232 made of material suitable for product contact, e.g. stainless steel. The cup 212, 232 is free to float in the ring 200, 230 for weighing. The end of each arm 186 is also equipped with a vertical lift device 234, 236 allowing the holding ring 200, 230 and cup 212, 232 to be lifted or lowered by a sufficient distance (for example, approximately 10mm as tested) to allow the cup 212, 232 to disengage from the holder 200, 230 and stand free on a load cell 190 for weighing. The cup 212, 232 is indexed overtop the load cell 190, the cup 212, 232 is lowered so that the cup 212, 232 and holding ring 200, 230 are disengaged and only the weight of the cup 212, 232 is applied to the load cell 190. The information from the load cell 190 may be simply recorded or monitored for quality control purposes, or may be communicated to the auger control system to provide “filler feedback”, i.e. running data used to adjust the operating parameters of the feed system during the operating cycle for the purpose of maintaining a higher level of accuracy.

[000141] It will be understood that, although various features of the invention have been described with respect to one or another of the embodiments of the invention, the various features and embodiments of the invention may be combined or used in conjunction with other features and embodiments of the invention as described and illustrated herein.

[000142] It is to be appreciated that the system 10 is not limited to the particular construction and dimensions as shown in the preferred embodiments, and that other suitable constructions and dimensions could be used instead. For example, the shape and size of the hopper 14 could be different from the shape and size of the hopper 14 shown in the drawings. The hopper agitation system 16 could also be different from the hopper agitation system 16 shown in the drawings. The screw auger feed mechanism 18 could also differ from the preferred embodiment shown, and may for example incorporate any suitable combination of the dimensions and characteristics described below.

[000143] The sleeve 82 is preferably close fitting on the auger 84, with for example a diametrical clearance of 0.002 inches to 0.025 inches. In various preferred embodiments, the inner diameter 108 of the sleeve 82 is no more than 0.025 inches larger than the outer diameter 166 of the auger 84, no more than 0.02 inches larger than the outer diameter 166 of the auger 84, no more than 0.01 inches larger than the outer diameter 166 of the auger 84, no more than 0.05 inches larger than the outer diameter 166 of the auger 84, or no more than 0.02 inches larger than the outer diameter 166 of the auger 84. [000144] The auger 84 preferably has a pitch of 1 to 7.5 tpi. Lower pitches have been found to lead to higher compaction density in the screw 84, more chance of bridging/clogging, and reduction in flow rate without a corresponding gain in accuracy. Higher pitches have been found to require more torque and produce less consistent compaction density in the screw 84, resulting in higher operating wear and less accuracy. In various preferred embodiments, the auger 84 has a pitch of 1 to 5 tpi, 2 to 4 tpi, 2.5 to 3.5 tpi, or about 3 tpi.

[000145] The leading face angle 172 is preferably 75 to 105 degrees relative to the longitudinal axis 140. If the leading wall 160 angles away from the direction of flow, product tends to be forced towards the gap between the auger 84 and sleeve 82 at the perimeter of the leading face 160, encouraging buildup on the auger land surface 162 or on the inside of the sleeve 82, with the potential to cause binding. If the wall 160 leads forward more than a few degrees, stagnation and/or buildup of product in the base of the groove is encouraged which can result in inconsistent operation and more frequent cleaning intervals. In some preferred embodiments the leading face angle 172 is 85 to 95 degrees, or most preferably about 90 degrees.

[000146] Preferably, the trailing face angle 170 is greater than 90 degrees, or in other words, the trailing face 158 is angled towards the leading face 160 as the trailing face 158 extends radially outwardly from the cylindrical core 150. It is advantageous to have a taper in the groove cavity as this reduces the likelihood of bridging/clogging, and allows the product to fall clear of the grooves readily at the discharge point. In various preferred embodiments the trailing face angle 170 is greater than 90 degrees, greater than 100 degrees, greater than 110 degrees, greater than 115 degrees, or about 117 degrees.

[000147] Preferably, the land width 168 is kept to a practical minimum in order to maximize the free volume in the auger 84, reduce product compression, thereby assisting flow rate and helping to avoid bridging/buildup. Considerations are given towards factors such as ease of manufacture, mechanical durability, and durability of the polymer coating on the land surface 162. In various preferred embodiments the land width 168 is no more than 0.075 inches, no more than 0.07 inches, no more than 0.065 inches, no more than 0.06 inches, or about 0.058 inches. [000148] The height or depth 250 of the thread 152 is preferably based upon the auger outside diameter 166, and the core diameter 164 needed to provide adequate structural rigidity to the auger assembly. For example, in one preferred embodiment the auger 84 has an outer diameter 166 of about 0.875 inches and the thread 152 has a depth 250 of about 0.25 inches, resulting in a central core diameter 164 of about 3/8 inches. For any given auger diameter 166, the threads 152 will preferably be made as deep as possible to reduce the dimensional constraints in the cavity and thereby provide the maximum free volume for product and maximum resistance to bridging/clogging. In various preferred embodiments the depth 250 of the thread 152 is at least 0.25 inches, at least 0.2 inches, at least 0.15 inches, at least 0.1 inches, about 0.25 inches, or about 0.114 inches.

[000149] The auger 84 preferably has an outer diameter 166 of 0.5 inches to 1.25 inches. If the outer diameter 166 is too small it is more prone to bridging. Too large reduces precision by requiring fewer rotations per dose and hereby increasing the dosage error per degree of rotational error. In various preferred embodiments the auger 84 has an outer diameter of 0.75 inches to 1 inch, 0.8 inches to about 0.9 inches, or about 0.875 inches.

[000150] The auger 84 preferably has a length 178 of 5 inches to 12 inches. Too short results in poor supply of product to the screw 84 and inconsistent density of the product in the screw 84 resulting in dose fluctuation. Too long increases the chance of bridging/clogging with product. In various preferred embodiments the auger 84 has a length 178 of 8 to 10 inches, 9 to 10 inches, or about 9.25 inches.

[000151] The term “ground cannabis” as used herein is intended to refer broadly to any preground cannabis product, and is used interchangeably with other similar terms such as “milled cannabis”.

[000152] The system 10 is preferably used to discharge the doses of the ground cannabis 12 at a rate that is faster than conventional feeding systems. In various preferred embodiments the servo motor drive 20 is controlled to deliver at least 40 doses per minute from the screw auger feed mechanism 18; at least 50 doses per minute from the screw auger feed mechanism 18; at least 75 doses per minute from the screw auger feed mechanism 18; at least 100 doses per minute from the screw auger feed mechanism 18; at least 125 doses per minute from the screw auger feed mechanism 18; at least 150 doses per minute from the screw auger feed mechanism 18; or at least 200 doses per minute from the screw auger feed mechanism 18. In various preferred embodiments the servo motor drive 20 is controlled to rotate the auger 84 at a drive speed of at least 750 rotations per minute, at least 1000 rotations per minute, at least 1250 rotations per minute, at least 1500 rotations per minute, at least 1750 rotations per minute, at least 2000 rotations per minute, or about 2000 rotations per minute.

[000153] The check weighing system 184 could have a different construction from the one shown in the drawings. For example, the rotary member 186 could be configured to carry any desired number of vessels 212, 232, such as one, two, three, four, five, six, or more.

[000154] Although this disclosure has described and illustrated certain preferred embodiments of the invention, it is to be understood that the invention is not restricted to these particular embodiments. Rather, the invention includes all embodiments which are functional or mechanical equivalents of the specific embodiments and features that have been described and illustrated herein.

Claims

WE CLAIM:

1. A system for delivering doses of ground cannabis, comprising: a hopper for containing a bulk quantity of the ground cannabis; a screw auger feed mechanism for delivering the doses of the ground cannabis from the hopper; and a servo motor drive for driving the screw auger feed mechanism; wherein the screw auger feed mechanism comprises an auger that is received within a sleeve; wherein the sleeve has a first longitudinal end and a second longitudinal end; wherein the auger is supported at both the first longitudinal end and the second longitudinal end to prevent floating of the auger in the sleeve; and wherein the screw auger feed mechanism has a partially enclosed discharge port for directing the doses of the ground cannabis in a desired direction.

2. The system according to claim 1 , wherein the sleeve comprises: a cylindrical body; a first end housing member that is coupled to a first end of the cylindrical body; and a second end housing member that is coupled to a second end of the cylindrical body; wherein the first end housing member carries a first bushing that supports a first part of the auger at the first longitudinal end of the sleeve; wherein the second end housing member carries a second bushing that supports a second part of the auger at the second longitudinal end of the sleeve; wherein the sleeve is closed at the second longitudinal end to prevent the doses of the ground cannabis from being discharged longitudinally from the screw auger feed mechanism; wherein the second end housing member has a closed top portion that prevents the doses of the ground cannabis from being discharged upwardly from the screw auger feed mechanism; and wherein the second end housing member has an open bottom portion that defines the discharge port, and which discharges the doses of the ground cannabis downwardly from the screw auger feed mechanism.

3. The system according to claim 1 or claim 2, wherein the auger has a non-stick polymer coating; wherein the auger has a pitch of about 3 tpi; and wherein the auger has a leading face angle of about 90 degrees relative to a longitudinal axis of the auger.

4. The system according to claim 1 or claim 2, wherein the sleeve has an inner diameter and the auger has an outer diameter, the inner diameter of the sleeve being no more than 0.025 inches larger than the outer diameter of the auger; wherein the auger has a pitch of 1 tpi to 7.5 tpi; wherein the auger has a non-stick outer surface; and wherein the auger has a leading face angle of 75 to 105 degrees relative to a longitudinal axis of the auger.

5. The system according to claim 4, wherein the auger has a land width of no more than 0.075 inches; wherein the inner diameter of the sleeve is no more than 0.02 inches larger than the outer diameter of the auger; wherein the pitch of the auger is 2 tpi to 4 tpi; wherein the leading face angle of the auger is 85 to 95 degrees relative to the longitudinal axis of the auger; wherein the outer diameter of the auger is 0.5 to 1.25 inches; wherein the auger has a length of 5 to 12 inches; and wherein the auger has a trailing face angle that is greater than 90 degrees relative to the longitudinal axis of the auger.

6. The system according to claim 5, wherein the pitch of the auger is about 3 tpi; wherein the leading face angle of the auger is about 90 degrees relative to the longitudinal axis of the auger; wherein the inner diameter of the sleeve is no more than 0.005 inches larger than the outer diameter of the auger; wherein the land width of the auger is no more than 0.06 inches; wherein the outer diameter of the auger is about 0.875 inches; wherein the auger has a thread depth of at least 0.1 inches; wherein the length of the auger is about 9.25 inches; and wherein the trailing face angle of the auger is about 117 degrees relative to the longitudinal axis of the auger.

7. The system according to any one of claims 1 to 6, wherein the auger is constructed of a material that is compatible with a non-stick coating process, or that has inherent non-stick properties.

8. The system according to any one of claims 1 to 7, wherein the auger is constructed of at least one of: stainless steel, aluminum, and engineering plastic.

9. The system according to claim 3, wherein the auger is formed from aluminum; and wherein the non-stick polymer coating is a food-grade non-stick polymer coating.

10. The system according to any one of claims 1 to 9, wherein the sleeve has an opening for receiving the ground cannabis from the hopper; wherein the opening has a planar first longitudinal side that lies in a first side plane; wherein the opening has a planar second longitudinal side that lies in a second side plane, the first longitudinal side being spaced from the second longitudinal side; wherein the first side plane and the second side plane are parallel to a center plane that contains a longitudinal axis of the sleeve and a center of the opening; wherein the first longitudinal side and the second longitudinal side each have an inner edge; and wherein the inner edge of the first longitudinal side is oriented at an angle of 90 degrees to 180 degrees relative to the inner edge of the second longitudinal side, the longitudinal axis of the sleeve forming the vertex of the angle.

11. The system according to any one of claims 1 to 10, further comprising a wheel agitator that is located inside the hopper, the wheel agitator having agitating blades that agitate the ground cannabis when the wheel agitator is rotated.

12. The system according to any one of claims 1 to 10, further comprising a hopper agitation system for agitating the ground cannabis in the hopper, the hopper agitation system comprising: at least one vertically extended agitator shaft that carries a plurality of finger blades; and a wheel agitator that carries a plurality of agitating blades; wherein the agitator shaft rotates about a vertical axis to agitate the ground cannabis in the hopper; and wherein the wheel agitator rotates about a horizontal axis to agitate the ground cannabis in the hopper and to direct the ground cannabis in the hopper towards an upstream portion of the auger that is spaced from the discharge port.

13. The system according to claim 12, wherein the wheel agitator is formed from stainless steel; wherein the agitating blades extend from a face of the wheel agitator; wherein the wheel agitator has at least four of the agitating blades; wherein two of the agitating blades each have a linear shape when viewed facing towards the face of the wheel agitator; and wherein two of the agitating blades are each v-shaped when viewed facing towards the face of the wheel agitator.

14. The system according to any one of claims 1 to 13, further comprising: a weighing device; and a rotary arm that carries a vessel; wherein the rotary arm is rotatable about a vertical axis to move the vessel between a fill station and a dump station; wherein the rotary arm is vertically movable along the vertical axis between a raised position and a lowered position; wherein the vessel is positioned below the discharge port for receiving the ground cannabis discharged from the screw auger feed mechanism when the vessel is at the fill station; wherein the vessel is positioned above the weighing device when the vessel is at the fill station; wherein the rotary arm has a carrying surface that engages with a catch surface of the vessel to support the vessel when the vessel is at the fill station and the rotary arm is at the raised position; wherein a bottom surface of the vessel engages with the weighing device when the vessel is at the fill station and the rotary arm is lowered from the raised position to the lowered position; wherein the catch surface of the vessel disengages from the carrying surface of the rotary arm when the vessel is at the fill station and the rotary arm is lowered from the raised position to the lowered position; and wherein the weighing device measures a weight of the ground cannabis received by the vessel from the screw auger feed mechanism when the vessel is at the fill station and the rotary arm is at the lowered position.

15. A method comprising: providing the system as claimed in any one of claims 1 to 14; placing the bulk quantity of the ground cannabis in the hopper; and using the servo motor drive to rotate the auger within the sleeve, to thereby deliver the doses of the ground cannabis from the discharge port.

16. The method according to claim 15, further comprising: controlling the servo motor drive to rotate the auger at a drive speed of about 2000 rotations per minute.

17. The method according to claim 15 or claim 16, further comprising: controlling the servo motor drive to deliver at least 150 of the doses of the ground cannabis per minute from the discharge port.

18. The method according to any one of claims 15 to 17, further comprising: controlling the servo motor drive so that at least some of the doses of the ground cannabis have 1.5 grams or less of the ground cannabis.

19. The method according to any one of claims 15 to 17, further comprising: controlling the servo motor drive so that at least some of the doses of the ground cannabis have 0.25 grams or less of the ground cannabis.

20. The method according to any one of claims 15 to 19, wherein the system is used as a secondary filling system, the method further comprising: using a primary filling system to dispense a primary dose of cannabis below a target weight; measuring a weight of the primary dose of cannabis; and using the secondary filling system to dispense a secondary dose of the ground cannabis; wherein the weight of the primary dose of cannabis is used as an input for controlling the secondary filling system so that a weight of the secondary dose of the ground cannabis dispensed from the secondary filling system, when combined with the weight of the primary dose of cannabis dispensed from the primary filling system, is equal to the target weight plus or minus 10%.

21. The method according to claim 20, wherein the primary dose of cannabis comprises chopped cannabis flower.

22. The method according to any one of claims 15 to 19, wherein the system is used as a dosing system for manufacturing pre-rolled cannabis joints.

23. The method according to any one of claims 15 to 22, further comprising: weighing the ground cannabis that is discharged from the discharge port; and adjusting operation of the servo motor drive based on a weight of the ground cannabis that is discharged from the discharge port.

24. The method according to any one of claims 15 to 23, further comprising: collecting the ground cannabis discharged from the discharge port in a vessel carried by a rotary arm; weighing the ground cannabis received by the vessel; rotating the rotary arm away from the discharge port; and discharging the ground cannabis from the vessel.