Assembly and method for gravitationally separating gold from small particles

Abstract

An assembly and method for gravitationally separating gold from particles, and specifically for separating small components of gold, less than 1 millimeter from small particles. A series of sieves having graduated mesh sizes, and arranged in a sequential, stacked configuration sieves the aggregate of large particles and larger components of gold. The remaining small particles and smaller components of gold fall into a container. A pressurized column of fluid is forced into the container. The fluid has sufficient flow velocity to suspend the lighter small particles, but insufficient flow velocity to support the denser, high specific gravity gold. Gold has a large specific gravity relative to the fluid and particles. Gravity causes the gold to falls into a transparent collection conduit. Manipulation of valves enables gold to redirect to a collection bin. Fluid flow is shut, enabling small particles to be flushed out through gravitational forces and excess fluid momentum.

Claims

1. A method for separating gold from small particles, the method comprising: sieving an aggregate of particles and gold, whereby large particles and large components of the gold are separated from small particles and small components of the gold; removing the large particles and large components of gold; forcing a pressurized column of fluid through a collection conduit having a downward curve, the collection conduit defined by a source end and a container end, wherein the source end and the container end are vertically above a lower curved portion of the collection conduit; the container end configured to join with an aperture of the container, wherein the pressurized column of fluid first flows in a direction with a force of gravity, and second flows in a direction opposite the force of gravity and towards the remaining small particles and the remaining gold; setting a flow velocity of the fluid whereby the flow velocity of the fluid imparts a force approximately equivalent to the force of gravity on the small particles and the gold so that the small particles and the gold are continuously suspended by the flow velocity of the fluid, adjusting the flow velocity of the fluid and inspecting visually through the collection conduit for gravitational separation until the gold falls against the flow velocity of the fluid based upon the density of the gold relative to flow velocity of the fluid and density of the small particles until the small particles and the gold are isolated from each other; redirecting the path of the gold for collection through an extraction conduit by opening an extraction valve in the extraction conduit, wherein the extraction conduit is in fluid communication with the container end of the collection conduit and has an opening into the container end of the collection conduit below the container valve; and discharging the small particles through forces of gravity and momentum from excess fluid.

2. The method of claim 1, wherein the step of sieving an aggregate of particles and gold, further comprises washing the aggregate of particles and gold.

3. The method of claim 1, wherein the step of sieving an aggregate of particles and gold is operable with a series of sieves having graduated mesh sizes.

4. The method of claim 3, wherein the series of sieves includes at least one member selected from the group consisting of: a inch mesh, a inch mesh, a inch mesh, a 1/16 inch mesh, a 1/32 inch mesh, and a 1/64 inch mesh.

5. The method of claim 1, wherein the step of forcing a pressurized column of fluid towards the remaining small particles and the remaining gold, further comprises at least partially opening a flow regulation valve.

6. The method of claim 5, wherein the step of restricting flow of the pressurized column of fluid, further comprises at least partially closing the flow regulation valve.

7. The method of claim 1, wherein the step of adjusting a flow velocity of the fluid until the small particles and the gold are substantially separated, further comprises retaining the gold in a collection conduit.

8. The method of claim 1, further comprising a step of stabilizing the flow of fluid with a pressure regulator.

9. The method of claim 1, wherein the step of redirecting the path of the gold for collection, further comprises closing a container valve and opening an extraction valve.

10. The method of claim 1, further comprising a step of inhibiting backflow of the fluid with a backflow prevention valve.

11. The method of claim 1, wherein the step of discharging the small particles through forces of gravity and momentum from excess fluid, further comprises opening a dump valve to enable carrying the small particles through a tailings conduit to a tailings drain.

12. The method claim 11, further comprising a step of shutting off the tailings drain.

13. A method for separating gold from small particles, the method comprising: sieving an aggregate of particles and gold, whereby large particles and large components of the gold are separated from small particles and small components of the gold; washing the aggregate of particles and gold; removing the large particles and large components of gold; forcing a pressurized column of fluid through a collection conduit having a downward curve, the collection conduit defined by a source end and a container end, the container end configured to join with an aperture of the container, wherein the pressurized column of fluid first flows in a direction with a force of gravity, and second flows in a direction opposite a force of gravity and towards the remaining small particles and the remaining gold; setting a flow velocity of the fluid whereby the flow velocity of the fluid imparts a force approximately equivalent to the force of gravity on the small particles and the gold so that the small particles and the gold are continuously suspended by the flow velocity of the fluid, adjusting the flow velocity of the fluid and inspecting visually through the collection conduit for gravitational separation until the gold falls against the flow velocity of the fluid based upon the density of the gold relative to flow velocity of the fluid and density of the small particles until the small particles and the gold are isolated from each other; separating the gold from the small particles by closing a container valve, wherein the container valve is located above the suspended gold in the collection conduit, and below the small particles, in a vertical portion of the container end of the collection conduit; redirecting the path of the gold for collection through an extraction conduit by opening an extraction valve in the extraction conduit, wherein the extraction conduit is in fluid communication with the container end of the collection conduit and has an opening into the container end of the collection conduit below the container valve; restricting flow of the pressurized column of fluid; and discharging the small particles through forces of gravity and momentum from excess fluid.

14. The method of claim 13, wherein the step of sieving an aggregate of particles and gold is operable with a series of sieves having graduated mesh sizes.

15. The method of claim 14, wherein the series of sieves includes at least one member selected from the group consisting of: a inch mesh, a inch mesh, a inch mesh, a 1/16 inch mesh, a 1/32 inch mesh, and a 1/64 inch mesh.

16. The method of claim 13, wherein the step of forcing a pressurized column of fluid towards the remaining small particles and the remaining gold, further comprises at least partially opening a flow regulation valve.

17. The method of claim 16, wherein the step of restricting flow of the pressurized column of fluid, further comprises at least partially closing the flow regulation valve.

18. The method of claim 13, wherein the step of adjusting a flow velocity of the fluid until the small particles and the gold are substantially separated, further comprises retaining the gold in a collection conduit.

19. The method of claim 13, further comprising a step of stabilizing the flow of fluid with a pressure regulator.

20. A method for separating gold from small particles, the method consisting of: sieving an aggregate of particles and gold through a series of sieves having graduated mesh sizes, whereby large particles and large components of the gold are separated from small particles and small components of the gold; washing the aggregate of particles and gold; removing the large particles and large components of gold; forcing a pressurized column of fluid through a collection conduit having a downward curve, the collection conduit defined by a source end and a container end, the container end configured to join with an aperture of the container, wherein the pressurized column of fluid first flows in a direction with a force of gravity, and second flows in a direction opposite a force of gravity and towards the remaining small particles and the remaining gold; at least partially opening a flow regulator valve; setting a flow velocity of the fluid whereby the flow velocity of the fluid imparts a force approximately equivalent to the force of gravity on the small particles and the gold so that the small particles and the gold are continuously suspended by the flow velocity of the fluid, adjusting the flow velocity of the fluid and inspecting visually through the collection conduit for gravitational separation until the gold falls against the flow velocity of the fluid; based upon the density of the gold relative to flow velocity of the fluid and density of the small particles until the small particles and the gold are isolated from each other; separating the gold from the small particles by closing a container valve, wherein the container valve is located above the suspended gold, and below the small particles, in a vertical portion of the container end of the collection conduit; stabilizing the flow of fluid with a pressure regulator; redirecting the path of the gold for collection through an extraction conduit by opening an extraction valve in the extraction conduit, wherein the extraction conduit is in fluid communication with the container end of the collection conduit and has an opening into the container end of the collection conduit below the container valve; at least partially closing the flow regulation valve; restricting the flow of the pressurized column of fluid; discharging the small particles through forces of gravity and momentum from excess fluid; opening a dump valve to enable carrying the small particles through a tailings conduit to a tailings drain; shutting off the tailing drain; and inhibiting backflow of the fluid with a backflow prevention valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

(2) FIGS. 1A, 1B, and 1C illustrates views of an exemplary assembly for gravitationally separating gold from small particles, where FIG. 1A is a perspective view, FIG. 1B is a blowup view of fully separated gold in a horizontal section of the collection conduit, and FIG. 1C is a blowup view of gold and small particles beginning separation in a vertical section of a collection conduit, in accordance with an embodiment of the present invention;

(3) FIG. 2 illustrates a rear perspective of the assembly for gravitationally separating gold from small particles shown in FIG. 1A, in accordance with an embodiment of the present invention;

(4) FIG. 3 illustrates an upper angle perspective of an exemplary aggregate being washed through a plurality of sieves, in accordance with an embodiment of the present invention;

(5) FIG. 4 illustrates a perspective view of the sieves in a graduated relationship, in accordance with an embodiment of the present invention;

(6) FIG. 5 illustrates a diagram of the assembly shown in FIG. 1A, where the aggregate passes through the sieves, in accordance with an embodiment of the present invention;

(7) FIG. 6 illustrates a diagram of the assembly shown in FIG. 1A, where a high pressure column of fluid flows through a collection conduit against both small particles and gold, beginning the gravitational separation, in accordance with an embodiment of the present invention;

(8) FIG. 7 illustrates a diagram of the assembly shown in FIG. 1A, where the gold is fully separated from the small particles and retained in the collection conduit, in accordance with an embodiment of the present invention;

(9) FIG. 8 illustrates a diagram of the assembly shown in FIG. 1A, where the gold is redirected through an extraction conduit for collection, in accordance with an embodiment of the present invention;

(10) FIG. 9 illustrates a diagram of the assembly shown in FIG. 1A, where the small particles are discharged through a tailings conduit, in accordance with an embodiment of the present invention; and

(11) FIG. 10 illustrates a rear perspective of the method for gravitationally separating gold from small particles, in accordance with an embodiment of the present invention.

(12) Like reference numerals refer to like parts throughout the various views of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

(13) The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word exemplary or illustrative means serving as an example, instance, or illustration. Any implementation described herein as exemplary or illustrative is not necessarily to be construed as preferred or advantageous over other implementations. All of the implementations described below are exemplary implementations provided to enable persons skilled in the art to make or use the embodiments of the disclosure and are not intended to limit the scope of the disclosure, which is defined by the claims. For purposes of description herein, the terms upper, lower, left, rear, right, front, vertical, horizontal, and derivatives thereof shall relate to the invention as oriented in FIG. 1A. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

(14) FIGS. 1-10 illustrate an assembly 100 and method 200 for gravitationally separating gold 300 from particles, and specifically for separating small components of gold 300 from small particles 302. In some embodiments, assembly 100 operates in two stages. A first stage sieves an aggregate 304 of particles and gold 300 to remove larger components, i.e., greater than 1 millimeter. The second stage utilizes gravitational separation to separate the smaller components of gold 300 from the small particles 302. This is accomplished by leveraging the physical characteristic of gold 300namely having a large specific gravity relative to small particles 302 and a fluid used for separation.

(15) In one embodiment of the second stage a pressurized column of fluid flows against the aggregate of gold 300 and the small particles 302. The fluid has sufficient flow velocity to suspend the lighter small particles 302, but insufficient flow velocity to support the more dense gold 300. Thus, the gold 300 separates through forces of gravity and its own specific gravity, relative to the fluid and the small particles 302.

(16) As FIGS. 1A, 1B, and 1C illustrate, assembly 100 provides a container 104 defined by an open end 106, a sidewall 148, and a bottom end 108. The container 104 provides the volume for receiving the aggregate 304 after sieving. The container 104 serves primarily as a reservoir for retaining the small particles 302, gold 300, and excess fluid that pass through the sieves 102a-funtil the gold 300 falls through an aperture 110 in the bottom end 108 of the container 104 during separation. The sidewall 148 of the container 104 may be sloped and taper from the open end 106 to the bottom end 108. In one embodiment, the container 104 is a hopper with supportive legs. Thus, the container 104 is also portable.

(17) As discussed above, bottom end 108 of the container 104 comprises an aperture 110 through which fluid, gold 300, and small particles 302 pass through in various stages of the separation process. A container valve 124 proximal to aperture 110 of container 104 operates to regulate the flow of the fluid into container 104, so as to enable greater control of the separation process.

(18) In some embodiments, container 104 comprises a trough 112 that is configured to retain excess fluid. Trough 112 may encircle the periphery of container 104. Container 104 may also include a container conduit 114 configured to carry the excess fluid from trough 112. Container conduit 114 terminates at a fluid drain 116. In one embodiment, shown in FIG. 2, fluid drain 116 forms at one of the legs of container 104.

(19) Turning now to FIG. 3, assembly 100 further includes a series of sieves 102a-f having graduated mesh sizes for sieving an aggregate 304 of particles and gold 300. Series of sieves 102a-f are arranged in a sequential, stacked configuration. Sieves 102a-f are in general alignment with open end 106 of a container 104. Sieves 102a-f are configured to sieve an aggregate of particles and gold 300.

(20) Sieves 102a-f are arranged to graduate from a sieve 102a having a large mesh size, to a sieve 102f having a small mesh size, such that aggregate 304 of large particles and large components of gold are initially separated from the remaining small particles 302 and smaller components of gold 300, which gravity causes to fall through the smallest sieve 102f, and through open end 106 of the container 104.

(21) Those skilled in the art will recognize that the large, denser aggregate particles 304 trapped in the series of sieves 102a-f may consist primarily of a black, magnetite sand, gravel, rocks, gemstones, and minerals. The small particles 302 may include sand sediment and small pebbles, and metal dust often found in the deposit and used for source material. The larger components of gold 300, as described here, are approximately greater than 1 millimeter in diameter. The smaller components of gold that fall through the sieves 102a-f with the small particles 302 are approximately less than 1 millimeter. Though, these dimensions are relative, and could be increased or decreased depending on particle composition and the type of ore being physically broken and separated.

(22) In one embodiment, a sieve 102f having a small mesh is proximal to open end 106 of container 104, and a sieve 102a having a large mesh is distal to open end 106 of container 104. In some embodiments, the aggregate 304 of particles and gold 300 may be washed while passing through the sieves 102a-f. Thus both the force of washing and gravity work together to separate the large particles and large components of gold through sieves 102a-f. Though in other embodiments, the separating capacity of sieves 102a-f may be adjusted to any size particles. The assembly is generally scalable.

(23) As FIG. 4 illustrates, the series of sieves 102a-f includes at least one member selected from the group consisting of: a sieve 102a having a inch mesh; a sieve 102b having a inch mesh; a sieve 102c having a inch mesh; a sieve 102d having a 1/16 inch mesh; a sieve 102e having a 1/32 inch mesh; and a sieve 102f having a 1/64 inch mesh (FIG. 4). In this manner, the various component sizes of gold 300 may be selectively separated and collected. However in other embodiments, more or less sieves could be used. In one alternative embodiment, more advanced sieving devices may be utilize, which have rectangular shaker boxes with slots instead of screens and use air flow instead of a liquid, such as water.

(24) It is significant to note however, that the smallest components of gold 300 may pass through the smallest of the meshnamely gold 300 having dimensions of 1 millimeter or less, such as flakes of gold 300. Thus, the assembly 100 utilizes a second stage of separation to separate these smaller components of gold 300 from small particles 302 that were also less than 1 millimeter and thus, passed through the sieve 102f having the smallest mesh.

(25) Looking back at FIG. 1A, assembly 100 comprises a collection conduit 118. Collection conduit 118 is defined by a source end 122 and a container end 120. Container end 120 is configured to detachably attach to aperture 110 of container 104. In one embodiment, collection conduit 118 is generally transparent. A fluid source 136 feeds the collection conduit 118 a fluid. The fluid may include water. Fluid source 136 provides the fluid that flows through collection conduit 118 and other conduits, described below. In one embodiment, an inline pump may be used to force the fluid from fluid source 136. Fluid may include, without limitation, fresh water, salt water, and a liquid having low specific gravity relative to gold 300

(26) Looking back at FIG. 1A, a flow regulation valve 138 is operational at the fluid source 136. Flow regulation valve 138 is configured to regulate the flow rate of the fluid through collection conduit 118, through aperture 110, and into container 104. Flow regulation valve 138 is configured to regulates, direct, or control the flow of a fluid (gases, liquids, fluidized solids, or slurries) by opening, closing, or partially obstructing the conduits in the assembly 100. Suitable valves for flow regulation valve 138 may include, without limitation, a butterfly valve, a gate valve, a ball valve, a hydraulic valve, and a motorized valve.

(27) As FIG. 5 shows, after sieving the aggregate of particles and gold 300, a pressurized column of fluid is forced upwardly, towards the aggregate of small particles 302 and remaining gold 300 that passed through sieves 102a-f. The flow velocity may be increased until the aggregate is fluidized and separation of gold 300 from particles begins (FIG. 6). The fluid has sufficient flow velocity to suspend the lighter small particles 302, but insufficient flow velocity to support the more dense gold 300. The gold 300 falls through the pressurized column of fluid through forces of gravity and the specific gravity of the gold 300, relative to the fluid and small particles 302. Thus, the gold 300 falls to a bottom end 108 of the container 104, through the aperture 110, and into a horizontal section of the collection conduit 118, as illustrated in FIG. 7.

(28) Further, the flow velocity of the fluid from fluid source 136 towards container 104 is controllable through flow regulation valve 138. In this manner, the pressure and volume of the fluid may be regulated until substantially only gold 300 falls through aperture 110 at bottom end 108 of container 104, and into collection conduit 118.

(29) Collection conduit 118 may be disposed vertically near the aperture 110, so as to optimize gravitational forces that carry the gold 300 through the collection conduit 118. In one embodiment, collection conduit 118 is disposed in a vertical orientation for about 0.5 meters from the aperture 110 at bottom end 108 of container 104. However as FIG. 1C illustrates, the vertical slope of collection conduit 118 progressively flattens to a horizontal disposition for retention of the separated gold 300. Thus, when gold 300 ceases to fall through aperture 110 at bottom end 108 of container 104 and collect in the horizontal section of collection conduit 118, this indicates that gold 300 is substantially separated from small particles 302 (FIG. 1B).

(30) At this point of the separation process, container valve 124 at container end 120 of collection conduit 118 is closed to restrict flow of the fluid into container 104 and prevent small particles 302 from falling into collection conduit 118. An extraction conduit 126 is in communication with collection conduit 118. Extraction conduit 126 is configured to carry the gold 300 from collection conduit 118 to a collection bin 134, as illustrated in FIG. 8.

(31) Extraction conduit 126 is defined by a first end 128 and a second end 130. In one embodiment, first end 128 is in communication with container end 120 of collection conduit 118. An extraction valve 132 along extraction conduit 126 may be opened to enable the flow velocity of the fluid to carry the separated gold 300 from collection conduit 118, through extraction conduit 126, and towards the second end 130 of extraction conduit 126. A collection bin 134 is configured to join with second end 130 of the extraction conduit 126 for collection of gold 300.

(32) After gold 300 is collected in collection bin 134, the extraction valve 132 is closed to shut off communication with gold 300 in the collection bin 134. Then, flow regulation valve 138 is closed to shut off the flow of fluid towards container 104. Then, container valve 124 is opened to enable discharge of the small particles 302 from container 104, through aperture 110 in bottom end 108 of container 104, and into the collection conduit 118.

(33) Looking now at FIG. 9, the assembly 100 provides a dump valve 140 to regulate the flow of the fluid and the small particles 302 from collection conduit 118 to a tailings drain 142. Dump valve 140 may be opened so that the remaining small particles 302 in bottom end 108 of container 104 and collection conduit 118 can be carried through a tailings conduit 146 that leads to tailings drain 142. Tailings conduit 146 is in communication with source end 122 of collection conduit 118, and enables discharge of the remaining small particles 302 into tailings drain 142.

(34) It is significant to note that the force of gravity and momentum from excess fluid that has accumulated in the container 104 is the primary force that carries small particles 302 from container 104, through collection conduit 118 and tailings conduit 146, and finally for discharge at tailings drain 142.

(35) In one embodiment, a backflow prevention valve 144 may be operatively connected to tailings drain 142 to restrict undesirable backflow in the collection conduit 118, which may block the free backflow of small particles 302, and also cause contamination of the fluid. The backflow prevention valve 144 is also useful for preventing the loss of any gold 300 if fluid supply pressure is lost. In one embodiment, the backflow prevention valve 144 only operates when a D/C pump is used. When the D/C pump is turned off the liquid, particles, and any material flow back into the D/C pump.

(36) In another embodiment, container 104 may include a trough 112 for retaining excess fluid that accumulates. Trough 112 may encircle periphery of container 104, so as to capture all excess fluid flowing therein. It is significant to note that when the assembly 100 is operating, excess fluid becomes problematic. Trough 112 helps capture and redirect excess fluid away from assembly 100. A container conduit 114 leading from trough 112 carries the excess fluid out. Container conduit 114 may join with a fluid drain 116 that discharges the excess fluid.

(37) FIG. 10 illustrates a flowchart diagram of an exemplary method 200 for separating gold 300 from small particles 302. Method 200 comprises an initial Step 202 of sieving an aggregate of particles and gold 300, whereby large particles and large components of the gold 300 are separated from small particles 302 and small components of the gold 300. In some embodiments, Step 202 of sieving an aggregate of particles 304 and gold 300, further comprises washing aggregate 304 containing particles and gold.

(38) In other embodiments, Step 202 of sieving an aggregate 304 of particles and gold is operable with a series of sieves 102a-f having graduated mesh sizes (FIGS. 3 and 4). Sieves are primarily utilizes to remove the large particles and the larger components of gold. Sieves 102a-f includes at least one member selected from the group consisting of: a inch mesh, a inch mesh, a inch mesh, a 1/16 inch mesh, a 1/32 inch mesh, and a 1/64 inch mesh.

(39) In some embodiments, a Step 204 may include removing the large particles and large components of gold 300. The large particles and larger components of gold 300 may be approximately larger than 1 millimeter in diameter. In some embodiments, the remaining gold 300 after removal of the large particles and large components of gold is smaller than about 1 millimeter. The remaining small particles 302 may include sand particles, small pebbles, and mineral fragmentsall having passed through sieves 102a-f, and about less than 1 millimeter in diameter.

(40) A Step 206 may include forcing a pressurized column of fluid towards the remaining small particles 302 and the remaining gold 300 (FIG. 6). After the sieving process removes the large particles, the gravitational separation process begins through use of the pressurized column of fluid. In some embodiments, Step 206 of forcing a pressurized column of fluid towards the remaining small particles 302 and the remaining gold 300, further comprises opening a flow regulation valve 138 to regulate the volume and pressure of the pressurized column of fluid.

(41) A Step 208 includes adjusting a flow velocity of the fluid until the small particles 302 and the gold 300 are substantially separated, whereby the small particles 302 are suspended by the flow velocity of the fluid, whereby the gold 300 falls against the flow velocity of the fluid through forces of gravity and the specific gravity of the gold 300 relative to the fluid and small particles 302 (FIG. 7). Here the flow regulation valve 138 may be operated. Visual inspection of the gravitational separation allows for precise adjustments. Gold 300 eventually rests in a horizontal section of the collection conduit 118.

(42) Another Step 210 includes redirecting the path of the gold 300 for collection (FIG. 8). In some embodiments, Step 210 of redirecting the path of the gold 300 for collection, further comprises closing a container valve 124 and opening an extraction valve 132. Step 210 may also include collecting the gold 300 in a collection bin 134. A Step 212 may include restricting flow of the pressurized column of fluid. In some embodiments, Step 212 comprises closing the flow regulation valve 138 to enable the excess fluid in the container and gravity to carry the small particles 302 for discharge. Step 212 may also include closing an extraction valve 132 that regulates access to extraction conduit 126.

(43) A final Step 214 comprises discharging the small particles 302 through forces of gravity and momentum from excess fluid (FIG. 9). The Step 214 may require opening a dump valve 140 to enable carrying the small particles 302 through a tailings conduit 146, which leads to a tailings drain 142. A backflow prevention valve 144 may be used to prevent undesirable backflow through tailings conduit 142 and collection conduit 118.

(44) These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims and appended drawings.

(45) Since many modifications, variations, and changes in detail can be made to the described preferred embodiments of the invention, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. Thus, the scope of the invention should be determined by the appended claims and their legal equivalence.