| 1. A Weight hopper installation comprising:a rigidly | | | | These and other objects and advantages of the |
| supported frame including a load beam extending | | | | invention will be described below with reference to |
| substantially horizontally at a first elevation;a Weight | | | | the accompanying drawings, in which: |
| hopper having a variable weight and a center of | | | | FIG. 1 is a side elevation view of a Weight hopper |
| gravity situated laterally adjacent to the frame, said | | | | installation in accordance with the present invention; |
| hopper including a substantially planar front wall | | | | FIG. 2 is a top view of the installation shown in FIG. 1; |
| oriented transversely to the load beam and having a | | | | and |
| width dimension and a height dimension;means for | | | | FIG. 3 is a view of the front of the hopper, taken |
| supporting substantially all the weight of the Weight | | | | along line 3--3 of FIG. 2. |
| hopper through a load cell interposed between the | | | | DESCRIPTION OF THE PREFERRED EMBODIMENT |
| frame and the weight hopper, said means for | | | | FIGS. 1-3 show a Weight hopper installation 10 in a mill |
| supporting the weight of the hopper including a | | | | or plant, consisting of the basic components of a |
| vertically oriented rod having upper and lower | | | | girder 12 or the like, which would typically be a part |
| portions, one of said rod portions being attached to | | | | of the building structure, a support frame 14 welded |
| the support beam and the other of said rod portions | | | | or otherwise rigidly attached to the girder 12, and a |
| being attached to bracket means mounted on the | | | | hopper assembly 16, supported by the frame 14 and, |
| Weight hopper front wall, such that said attached | | | | indirectly, by the girder 12. |
| portions of the rod are at elevations above and | | | | The hopper assembly 16 can have a variety of |
| below the hopper center of gravity, whereby the | | | | shapes that do not induce large twisting moments on |
| weight of the hopper and its contents is borne | | | | the supports. The hopper 16 preferably includes a |
| substantially entirely by the rod and said load cell; | | | | body portion 18 into which dry product is deposited, |
| andrestraint means in the form of semi-flexible strips | | | | and a feeder portion 38 which is integral with, or |
| connected laterally between the frame and the | | | | rigidly secured to, bottom of the body portion 18 via |
| hopper, for preventing horizontal movement of the | | | | interengaged flanges 34, 36. |
| Weight hopper while permitting vertical movement of | | | | The body portion 18 includes a substantially vertical |
| the hopper. | | | | front wall 20, opposed, parallel side walls 30 extending |
| The Weight hopper installation (10) includes a rigid | | | | perpendicularly from the front wall 20, and an oblique |
| support frame (14) and a hopper (16) having a center | | | | back wall 22. The upper portion of the body 18 can |
| of gravity (42) situated laterally adjacent to the | | | | include a substantially rectangular box 24 defining an |
| frame. Substantially all the weight of the hopper is | | | | inlet opening, which may be covered by a screen |
| supported through a load cell (54) carried by a rod | | | | member 26 hinged to the front of the box 24 or wall |
| (50) between the frame and the hopper, preferably | | | | at 28. |
| in tension. Restraint members (62, 64, 74) are | | | | The lower end or bottom of the body portion 18 |
| connected laterally between the frame and the | | | | defines another opening 32 leading to the feed |
| Weight hopper, for preventing horizontal movement | | | | portion 38, which contains a feeder screw or feed |
| of the hopper while permitting vertical movement of | | | | valve 40, as is well known in the art. For purposes of |
| the hopper. | | | | the present invention, Weight hopper portions 18 and |
| | | | 38 can be considered a unitary, rigid body having a |
| 2. Wherein the hopper extends vertically from a first | | | | center of gravity 42. The hopper 16 is preferably |
| elevation higher than the frame to a second elevation | | | | symetric about a line of symmetry 43 extending |
| lower than the frame. | | | | between the front wall 20 and back wall 22. |
| 3. Wherein the load cell is at substantially the same | | | | The support frame 14 is interposed between the |
| vertical elevation as the hopper center of gravity. | | | | girder 12 and the hopper 16. Preferably, the support |
| 4. Wherein the restraint means includes only two | | | | frame, or saddle, includes a column 44 extending |
| upper restraint members above the means for | | | | vertically from the horizontal girder 12, for a distance |
| supporting the Weight hopper and only one lower | | | | that is preferably less than the full vertical dimension |
| restraint member below the means for supporting | | | | of the hopper 16. A support beam 45 extends |
| the hopper. | | | | horizontally from column 44 at a first elevation, |
| 5. The Weight hopper of claim 1 wherein the restraint | | | | perpendicularly to the front wall 20 of the hopper, |
| means are in the form of composite plastic strips. | | | | and preferably along an extension of the line of |
| 6. Wherein said rod upper portion is attached to the | | | | symmetry 43 of the hopper, when viewed from |
| support beam above the hopper center of gravity, | | | | above as shown in FIG. 2. The support beam 45 is |
| and said rod lower portion is attached to said bracket | | | | rigidly connected to colum 44 in any manner, such as |
| means below the weight hopper center of gravity, | | | | by first brace 46. |
| for rigidly connecting the Weight hopper front wall to | | | | A cross brace member 47 is rigidly attached to either |
| said rod lower portion, whereby the weight of the | | | | the column 44 or load beam 45, and extends |
| hopper and its contents is borne substantially entirely | | | | horizontally in parallel with the front wall 20 of the |
| by the rod in tension; and the restraint means | | | | Weight hopper, on either side of the load beam 45. |
| includes,first and second, semi-flexible lateral restraint | | | | Preferably the length of the cross brace member 47 |
| members, each connected between the support | | | | is substantially equal to the width dimension of the |
| frame and the hopper front wall in spaced apart | | | | hopper front wall 20 as seen in FIG. 2, and situated |
| relation along said horizontal dimension above the load | | | | above load beam 45. A bracket 48 or other |
| cell; and a third semi-flexible lateral restraint member | | | | attachment means, for purposes to be described |
| connected between the support frame and the | | | | below, is provided at the lower end of column 44. In |
| hopper front wall below the load cell control system | | | | general, the cross brace member 47 is located at an |
| or weighing controller.(China Longxin's weighing | | | | elevation approximately the same as that of the |
| controllers can make the hopper scales work stability | | | | upper end of the hopper 16, and the bracket 48 is |
| and security.) | | | | situated at an elevation below the center of gravity |
| 7. The Weight hopper of claim 6, wherein the | | | | 42 of the hopper, near the lower extent thereof. |
| restraint means are in the form of flexible composite | | | | Near the free, or cantilevered end of the support |
| plastic strips. | | | | beam 45, a rigid rod having an upper portion 50a and |
| 8. A Weight hopper installation comprising:a rigid | | | | a lower portion 50b extends vertically adjacent the |
| girder;a support frame rigidly connected to the girder | | | | front wall 20 of the hopper controller. The upper |
| and including a load beam extending substantially | | | | portion 50a of the rod is secured, as at 52, to the |
| horizontally from the girder at a first elevation;a | | | | support beam 45, and the lower portion 50b is rigidly |
| hopper situated in spaced relation adjacent the | | | | secured to the Weight hopper 16 through an |
| support beam, said hopper having a center of gravity | | | | attachment at 58 to a bracket 56 which is, in turn, |
| and a front wall oriented transversely to the load | | | | welded or otherwise formed as a integral part of the |
| beam, the front wall extending horizontally with a | | | | hopper. |
| width dimension and extending vertically with a height | | | | A weighing load cell 54 is interposed between the |
| dimension from above said first elevation to a second | | | | upper and lower portions 50a, 50b, of the rod, for |
| elevation below said first elevation;a vertically | | | | generating an output signal comensurate with the |
| oriented tension rod having upper and lower portions, | | | | tension load. This tension arises from the |
| the upper portion being attached to the support | | | | arrangement whereby substantially the entire weight |
| beam above the Weight hopper center of gravity, | | | | of the hopper 16 and its contents, is borne by the |
| and the lower portion of the rod extending below | | | | rod 50 and associated cell 54. In the illustrated |
| said center of gravity;means for rigidly connecting | | | | embodiment, this load is a tension load, and the cell is |
| the hopper front wall to said second portion of the | | | | a tension load cell. A suitable low cost cell is available |
| rod, whereby the weight of the weight hopper and | | | | commercially as the S type model TC-5-500 from |
| its contents is borne substantially entirely by the rod | | | | Eagle Micro Systems, Chester Springs, Pa. |
| in tension;first and second semi-flexible lateral | | | | As can be more clearly seen in FIG. 2, the line of |
| restraint members, each connected in spaced apart | | | | symetry 43 of the hopper, if extended horizontally, |
| relation between the support frame and the hopper | | | | passes through either the load cell or the upper or |
| front wall above the hopper center of gravity and | | | | lower rod portions 50a, 50b. Moreover, it may also be |
| substantially in parallel with the load beam and;a third | | | | appreciated that, as viewed in FIG. 1, the attachment |
| semi-flexible lateral restraint member connected | | | | of tension rod 50 to the support beam 45, is above |
| between the support frame and the hopper front | | | | the hopper center of gravity 42, and the attachment |
| wall below the hopper center of gravity. | | | | of tension rod 50 to the Weight hopper 16 via 56, is |
| 9. The Weighing Weight hopper installation of claim 8, | | | | below the hopper center of gravity. The distance |
| wherein the lateral restraint members are in the form | | | | between attachment points 52 and 58 should extend |
| of composite plastic strips. | | | | sufficiently in the vertical direction, to span the |
| 10. The Weight hopper installation of claim 8, | | | | variable location of the hopper center of gravity 42 |
| whereinthe girder extends horizontally, andthe | | | | resulting from empty to fully load conditions. Similarly, |
| support frame includes,a column rigidly attached to | | | | as shown in FIG. 2, the center of gravity 42 remains |
| and extending vertically from the girder,said load | | | | generally on the axis of symetry 43, although it may |
| beam, which is rigidly attached to and extends | | | | move slightly along that line as viewed in FIG. 2 |
| horizontally from the column toward the hopper front | | | | between the empty and full condition of the hopper. |
| wall,a brace member rigidly attached to one of the | | | | Since the hopper assembly center of gravity is close |
| column or load beam and extending horizontally on | | | | to the geometric center relative to the vertical |
| either side of the load beam in parallel with the front | | | | support point 52, the loading, unloading, and other |
| wall, and to which said first and second lateral | | | | forces acting on the hopper during operation, |
| restraint members are attached, andmeans for | | | | produce only minimal twisting moments about a |
| attaching the third third lateral restrain member to | | | | vertical axis 80 which passes through the center of |
| said column. | | | | gravity 42. |
| Description: | | | | In a significant feature of the present invention, |
| BACKGROUND OF THE INVENTION | | | | lateral constraint of the Weight hopper 16 can be |
| The present invention relates to Weight hoppers, | | | | accomplished from only one side, preferably the front |
| such as those used for metering a flowable solid such | | | | wall 20, thereby minimizing encumberances on three |
| as feed or the like. | | | | sides of the hopper. Moreover, with the present |
| Conventionally, where a dry product is metered | | | | invention, both the load support and the lateral |
| through a hopper or vessel by weight subtraction, a | | | | support interact with the front wall of the hopper, |
| load cell system is utilised with the hopper. This | | | | within the vertical dimensions defined by the top and |
| configuration provides a positive means for metering | | | | bottom of the hopper, thereby unencumbering the |
| the product, which can be set to alarm in the event | | | | space above the hopper. |
| of material bridging or clogging in the feeder. Although | | | | This is accomplished by providing first and second, |
| conventional Weight hoppers perform their intended | | | | semi-flexible restraining members 62, 64, connected |
| function satisfactorily, the support system for the | | | | at 66, 70 to the brace member 47, and at 68, 72 to |
| hopper is typically relatively complex in order to | | | | the front wall 20 of the hopper respectively, so as to |
| properly cooperate with multiple load cells. This often | | | | extend in parallel on either side of the support beam |
| encumbers free access to the top of the weigh | | | | 45. Preferably, the restraint members 62, 64 are |
| hopper. In addition, the need for lateral support often | | | | connected to the hopper, at the widest dimension as |
| encumbers at least two or three sides of the Weight | | | | viewed in FIG. 2. Similarly, a third, semi-flexible |
| hopper. | | | | restraining member 74 extends between bracket 48 |
| SUMMARY OF THE INVENTION | | | | at connection 76, to the front of hopper 16, for |
| It is, accordingly, an object of the present invention | | | | example at a connection 78 to the front wall 20 or |
| to provide a simple yet effective Weight hopper | | | | to the feeder portion 38 of the hopper. |
| system using a single, low-cost load cell . | | | | In general, the first and second, or upper, restraining |
| It is another object that the load cell and hopper | | | | members 62, 64 are at elevations above the center |
| support structure encumber only one side of the | | | | of gravity 42 of the Weight hopper, preferably |
| hopper. | | | | above the support point 52 of the tension rod 50. |
| A Weight hopper installation according to the | | | | The lower restraining member 74, is preferably |
| invention, includes a rigidly supported saddle frame, a | | | | situated below the center of gravity 42, and under |
| hopper situated laterally adjacent to the frame, and | | | | the attachment point 58 of the support rod 50 to |
| means, such as a rod member, for supporting | | | | the hopper. |
| substantially all the weight of the hopper through a | | | | The restraint members 62, 64 and 74 have sufficient |
| load cell interposed between the frame and the | | | | flexibility to hold the hopper in position against |
| hopper. To maintain static equilibrium of the Weight | | | | rotation or horizontal displacement, without removing |
| hopper, three horizontal lateral restraints, preferably | | | | the vertical load from the tension load cell or weight |
| constructed of semi-flexible composite plastic, extend | | | | transmitter or other transmitters. This is an important |
| between the frame and the hopper. The semi-flexible | | | | consideration for accurate, precise metering of the |
| restraints hold the hopper in steady position, yet do | | | | dry product. Preferably, the restraining members are |
| not remove the vertical load from the rod and load | | | | formed from strips or ribbons of flexible composite |
| cell. | | | | plastic, such as available commercially under the |
| Preferably, the rod member extends vertically, and is | | | | name, Scotch Ply. As used herein, the term |
| subjected to vertical loading whether the hopper is | | | | "semi-flexible" means that the material is capable of |
| empty or contains dry product. Only minimal twisting | | | | carrying high tension loads, and at least moderate |
| moments develop about the axis perpendicular to the | | | | compression loads, without flexure, but is relatively |
| planes along which the lateral restraints extend from | | | | elastic in response to bending loads. |
| the frame to attachments at the hopper. The lateral | | | | It should be appreciated that, although a tension rod |
| restraints are able to carry small moments about this | | | | and tension load cell embodiment have been |
| axis, which eliminates the need to install restraints on | | | | disclosed, the principle of the present invention can |
| more than one side of the hopper. | | | | also be implemented using a compression rod and |
| This simple weigh system is virtually maintenance | | | | compression load cell. In such embodiment, the upper |
| free, unaffected by dirt and contamination, and low in | | | | load beam 45 would be below the center of gravity, |
| cost, because there are no bearings or machined | | | | and the attachment point such as 58 to the Weight |
| surfaces. | | | | hopper would be above the center of gravity 42. |
| BRIEF DESCRIPTION OF THE DRAWINGS | | | | |