US3045840A - Material spreading mechanism - Google Patents

Description

July 24, 1962 H. J. DoNELsoN, JR 3,045,840

MATERIAL SPREADING MECHANISM vFiled June 30, 1961 3 Sheets-$hee1-I 1 July 24, 1962 H, J, DONELSQN, JR 3,045,840

MATERIAL SPREADING MECHANISM Filed June 30, 1961 3 Sheets-Sheet 2 /YOM/ @TMll/.95 177101675/ .5'

July 24, 1962 H. J, DQNELSON, JR 3,045,840

MATERIAL SPREADING MECHANISM 3 Sheets-Sheet 3 Filed June 30, 1961 Kil! INVENTOR.

5g/2W- l/OPA/f/S BY wf Mam/omyo/V Je United States Patent O 3,045,840 MATERIAL SPREADENG MECHANESM Harlan J. Donelson, Jr., Marshalltown, Iowa Filed .lune 30, 1961, Ser. No.. 121,102 11 Claims. (Cl. 21d-17) This invention relates to a material spreading means and more particularly to a spreader that will evenly and uniformly deposit material such as kernels of corn, silage, beans and the like in closed storage space areas such as granaries, silos, and the like.

The desirability of uniform density of materials in these storage areas has only become knowingly critical in rather recent times. The necessity became apparent with the new type of granaries wherein the material was aerated and/ or dry heated as it liowed into the storage housing. The air or heated air is passed tln'cugl'i the granary from bottom to top. lt is the custom to pour the grain or the like through a spout into the gr-anary from its top. The gra-in will first pile up in the bottom central area of the storage space and therefore will be much more dense or compact in such poured area than that of the surrounding area. This means that in the drying phase, the surrounding area will be successfully treated while the compacted area will not.

Furthermore, when the grain `or like piles up in a frusto-cone inside the bin, great downwardly and outwardly pressures are created, which may `well distort or break the side Walls of the bin. It is because of these problems that it has been the practice to place one or two workers with shovels in the granary lto move the grain or like around and to keep it horizontally level during the time it is being poured into the top of the bin.

Obviously, such work is most difficult as it is under heat and dust conditions.

Some effort has been to improve the situation and mechanical devices have been produced such `as is shown in my issued United States Letters Patent No. 2,980,009 issued April 18, 1961, on a Spreader for Confined Areas. While `this device was a considerable improvement over old methods, it did have certain shortcomings. Firstly, it did not automatically compensate for changing volume or grain or like being introduced into the device. Secondly, there `was no provision for changing nor ad justing the scattering means to meet different conditions. The present invention is an improvement on the device disclosed in my herebefore referred to issued patent.

Therefore, one ot the principal objects of my invention is to provide a means that will successfully, uniformly and evenly spread grain or the like into a granary or the like during the placement of the material into such storage space, and regardless of the changing volume of material being fed into the device.

A further object of this invention is to provide a scatter means for use when pouring material into la storage area that eliminates the need of workmen within the storage area at any time.

A still further object of this invention is to provide a material scattering means for granaries that cleans the objectionable chaff, dirt and the like from the material as it is being deposited 4in the storage area.

A still further object of this invention is to provide a material spreader for granaries or like that has adjustable material scattering blades.

A still further object of this invention is to provide a powered material spreader means that has a self cleaning belt driven power pulley Wheel.

A still fur-ther object of my invention is to provide a material spreader for confined areas that is economical of manufacture and durable in use.

These and other objects will be apparent to those skilled in the art.

My invention consists in the construction, arrangements, and combination, of the various parts of the device, whereby the objects contemplated -are attained as hereinafter more fully set forth, specifically pointed out in my claims, and illustrated in the accompanying drawings, in which:

FIG. 1 is a side sectional View of my device in use,

HG. 2 is a bottom view of a portion of the scatter wheel taken from line 2--2 of FlG. l,

FlG. 3 is la `top plan view of my device,

PEG. 4 is an enlarged perspective exploded view of the parts that control the movement of the grain or like passing through the device,

PEG. 5 is an enlarged side sectional view of a portion of the scatter 4wheel illustrating the vertical adjustment of one of the material scattering bars,

FlG. 6 is an end view of the scattering bar shown in FIG. 5 and is taken from line 6-6 of that tigure, and

IG. 7 is a side sectional of my device installed and in use.

in `trie drawings l have designated the ordinary granary by the numeral 1li, having lthe top central opening 11. The numeral 12 designates a conduit :having its outlet end communicating with the inside bottom of the granary and its other end adapted to be in communication with a source of air or heated air under pressure. Such air flow may be through the granary during and/or after the placement of Ithe material in the granary. l have used the numeral 13 to designate material such as grain or the like. lt is with such a storage space that I use my device and which l will now describe in detail. The numeral 15 designates a vertical tube housing open at both ends, and having a diameter less than that of the diameter of the opening 11 of the granary. Secured in the open upper end portion of the tube 15 in an upwardly flared tubular member 16 as shown in FIG. 1. The numeral 1'7 designates a plurality of our hook arms secured by bolt means 19 to the upper outer portion 0f the ared tubular member 16. These spaced apart hook arms 17 are vertically adjustably mounted on the member 16 by the member 16 having a plurality `of bolt receiving holes 2t). When the device is installed for use, the arms 17 hook over the rim of the top opening of the granary, thereby supporting the entire unit downwardly `within the upper portion of the granary as shown in FIG. 7. The tubular members 15 and 16 provide the main housing of the device and the upper end of the tubular member 16 is of a diameter less than that of the diameter of the upper open end 11 of the granary. The numeral Z1 designates a funnel shaped material receiving hopper vertically adjustably secured in the upper end portion `of the tubular member 16. The diameter of the lower portion of the hopper 2.1 lis much less than that of the diameter of the tubular member 16 and it lis held in spaced relationship to the tubular member I16 by brackets 22. The hopper 21 is vertically adjustable by any suitable means. In the drawings I sho-W bolt means 23 extending through the brackets 22 and through vertical slots 25 through the wall of the hopper. The numeral 26 designates a centrally located vertical bearing in the lower portion of the tubular member 15. T his bearing member is supported and held by the bolt means 27 as shown in FIG. 1. The numeral 29 designates a vertical rotatably mounted shaft journaled in the bearing 26. This shaft Z9 extends upwardly into the flared tubular portion 1o and is prevented from downward sliding movement by a retaining stop wall Ell engaging the upper end of the bearing 26. Rigidly secured on lthe lower end of the shaft 29 and directly below the bottom of the tubular member is the large belt pulley wheel 31 having the radially extending spokes 32 as shown lin FIG. 2. This wheel 31 has a diameter slightly greater than that of the diameter of the tubular member 1S and its upper outer rim portion extends upwardly to a horizontal plane slightly above the bottom horizontal plane of the member 15. The numeral 33 designates a =Cshaped bracket secured to the outer side of the tubular member 15. The numeral 35 designates a vertical rod rotatably but not slidably mounted on the bracket 33. The upper end portion 36 of the rod 35 is bent to extend horizontally and to extend horizontally about the top of lthe flared tubular member i6. The numeral 37 designates a bracket secured to the upper end of the tubular member i6. The numeral 39 designates a control lever having one end hingedly secured `to the outer end portion of the portion 36 of the rod 35 and its other end slidably extending over the bracket 37. The numeral i6 designates a wing nut extending through the bracket 37 and through a longitudinal slot i1 in the arm 39' as shown in PEG. 3. By this arrangement of parts the position rotation of the rod 35 may be adjustably selected and locked. The numeral 42 designates a plate on the lower end portion of the rod 35. `The numeral 4S designates an electric motor horizontally adjusta-bly secured to the plate ll2 by a bolt means d6. The power shaft i7 of the motor extends downwardly and has secured to its lower end the variable pitch pulley wheel t9. The numeral 5d designates an endless belt embracing the pulley wheels 3i and 49. Secured to the lower end of the bracket 33 is a bar having its length loosely embracing the belt 56 and with one of its ends extending into the groove of the pulley wheel 31 substantially directly -between the pulley wheel 49 and the pulley wheel 31 and at a point where the endless belt 36 is not engaging the pulley wheel 3d. The purpose of the end of the member so extending into ythe groove of the pulley wheel 31 is to automatically clear it of any foreign material that might collect in the pulley wheel groove. By the bent bar 51 loosely embracing the belt Sti, the belt even if it were to become detached from the pulley wheel 31 or pulley wheel 49 would be retained and prevented from yfalling downwardly into the bin and lost. By the arm 39 being adjustably positionable the motor may be swung horizontally to tighten the belt 5d or swung in the opposite direction to so loosen it that the pulley wheel 31 will not be rotated. This loosening of the belt 5@ on the pulley wheel 49, by its retention thereon, is aided by the bent bar 51 loosely embracing the belt. Therefore, the rotation of the pulley wheel 3i is controllable from a position at the top of the granary. When the device is installed, the grain or like 13 is deposited in the hopper 21 by any suitable conveyor means 152. The material placed in the hopper portion 21 will move downwardly yfrom the open bottom end of the hopper into the two portions 15' and 16 and thence downwardly and outwardly therefrom between the spokes 32 of the pulley Wheel 31. Therefore, it is necessary for the scattering action to be affected by lthe rotating `spokes of the large pulley wheel 31. To encourage this scattering action of the material as it falls through the pulley wheel 31, I provide material engaging scatter bar means 55 on each of the spokes 32 of the pulley wheel 31. I find that under different conditions and `for different materials, different types of scatter bars are desirable. Even with a given material being placed in the bin, the scatter bar means on the various spokes of the pulley wheel 31 should differ .from each other. All of the scatter `bar means regardless of type have a at base port-ion 56 which is secured by bolts 57 to the underside of a spoke 32. Each scatter bar :means also has a downwardly extending flange portion 59 with its inner corner end 60 bent downwardly and laterally to catch the falling grain las shown in FIG. 1. The scatter bar means may be longitudinally adjustable on the spokes by having the bolt means extend to slot openings 61 of the base portion as shown in FIG. 2. The widths and lengths of the downwardly extending flange portions 59 may and should vary. Also, at least on some of the scatter bars I provide a horizontally extending flange 62. The length of this horizontal elongated flange 62 extends downwardly and outwardly and is spaced apart and above the inner belt corner end portion 66. This elongated bar 62 may extend upwardly to a position above `a spoke 32 as shown by broken lines in FIG. l.

Obviously if the material entering the hopper 21 was fed into the hopper at a proper uniform rate, the material would be evenly scattered and distributed in the bin. To obtain a proper flow of material through the device and to even properly spread it within the device and before it is engaged by the material scattering bar means, it is necessary to provide a material control means directly below the open end of the hopper 21. However, the material feeding means 52 is not even as to volume iiow and therefore the control means must automatically adjust to ycompensate for their handling periodical large amounts of material in the hopper. I will now describe how this control portion of my device functions. The upper end portion of the shaft 29 is formed into a spiral auger portion 65. Slidably mounted on the upper portion of the shaft 29 is an elongated member 66. This elongated member 66 extends upwardly within the center area of the hopper 21 and has on its lower portion a horizontal radial plate 67 positioned below the bottom open end of the hopper 21 as shown in FIG. l. The numerals 69 and 70 designate two parallel spaced apart parts extending through the elongated member 66 and engaging each side respectively of the auger portion 65 of the shaft 29 as shown in FIG. 1. By this arrangement of parts any relative rotation between the elongated members 66 and shaft 29 will cause the cylinder to either move downwardly or upwardly depending upon the direction of its relative rotation to the shaft 29. Normally, however, the elongated member 66 will be held in an elevated position as shown in FIG. 1 by coiled spring 71 inside the upper end portion of the elongated member 66, having its upper end operatively connected to the elongated member 66 and its lower end yieldingly engaging the top of the shaft 29. Therefore, the coil spring 71 will yieldingly cause the elongated member 66 to rotate clockwise relative to the shaft 29 and move upwardly until the parts 69 and 70 engage the top head 72 of the shaft '29. The elongated member 66 supports two vertically adjustable material engaging arms 75 and 76. yBy this arrangement of parts material will pass from the hopper onto the spinning control plate 67 and from the plate 67 material will be cast downwardly and outwardly to the pulley wheel 31. However, if a great amount of material exists within 4the 'hopper 21 at any one time, the resistance bar arms 75 and 76 Will engage this mass of material and will tend to slow down the rotation of the shaft elongated member 66 relative to the shaft 29. This will cause the elongated member 66 and control plate 67 to move downwardly relative to the hopper 21 and permit a greater amount of material to pass by the control plate 67. As soon as the excess `amount of material in the hopper 21 has been disposed of, the resistance to the rotation of the arms 75 and 76 will be lessened accordingly and the spring 71 will cause the rotation of the elongated member 66 and plate 67 relative to the shaft 29 and the plate 67 will move upwardly to reduce the distance between the lower end of the hopper 21 and plate 67. In some situations and with different materials, it might be desirable to reverse the action of movement of the plate `67 and this may be accomplished merely by reversing the motor or reversing the rotation of the shaft 29. In such a case the plate 67 would move -upwardly to restrict and prevent an excessive amount of material from passing from the hopper through the device.

As before indicated, the scatter bars 55 may be longitudinally adjusted or even adjusted to extend downwardly at various angles as shown in FIG. 5 and FIG. 6. This may be accomplished by any suitable means such as placing washers or nuts between the spoke and scatter bar with the nuts or washers embracing the bolt means.

By the use of my device there will be no dense areas in the grain or the like accumulating in the bottom of the building. The grain or the like will be evenly distributed and if air or warmed air is passed upwardly through the grain or the like, the same will evenly and uniformly contact all of the material thereby drying it uniformly. Still another advantage realized by the use of my device is the separating and elimination of dust, chaff and the like foreign matter. The reason for this is that with the downwardly passing grain being scattered as shown in FIG. 7, the air column from the pipe l2 will pass upwardly through such separated kernels of grain carrying with it the undesired light foreign matter. The escape of this undesired foreign matter is made possible by having the diameter of the tubular housing 16 less than that of the diameter of the opening 1l. Also, by the hopper '2i being `spaced from the tubular member i6, the chaff, dirt and like 77 may pass upwardly between the inside of the tubular member i6 and the outer side of the hopper 2l. as shown in FIG. 7. Even if this rising air column does not remove all of the chaff and the like, the remaining foreign matter will be evenly distributed through the collected material in the bottom of the building.

From the foregoing it will be readily seen that the use of my device does not only eliminate workmen inside the building as it is being lled with material but it automatically uniformly deposits the grain or the like into the storage area. As herebefore indicated, my apparatus may be used for the depositing of various materials.

Some changes may be made in the construction and arrangement of my Material Spreading Mechanism without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

l claim:

1. In combination, a storage material building having an opening in its upper area, a vertical tubular housing secured to said building and associated with its opening, a vertical shaft rotatably mounted in said tubular housing, a spoked pulley wheel secured to the lower end of said shaft, material engaging bar fins on the spokes of said pulley wheel, a prime mover having a drive shaft, a pulley wheel on said drive shaft, an endless belt embracing said two pulley wheels, a hopper having an open bottom in the upper portion of said housing, an elongated member slidably embracing the upper end portion of `said shaft and extending upwardly into said hopper, means for directly transmitting rotation of said shaft to said elongated member, said means allowing sliding movement of said elongated member upon said shaft, a spring means for yieldingly holding said elongated member in one direction of its slidable movement on said shaft, a control plate on said elongated member and below said hopper, and at least one material engaging arm on said elongated member and positioned in said hopper.

2. In combination, a storage material building having an opening in its upper area, a vertical tubular housing detachably secured to said building and associated with its opening, a vertical shaft rotatably mounted in said tubular housing, a spoked pulley Wheel secured to the lower end of said shaft, material engaging bar tins on the spokes of said pulley Wheel, a prime mover having a drive shaft, a pulley Wheel on said drive shaft, an endless belt embracing said two pulley wheels, a hopper having an open bottom in the upper portion of said housing, an elongated member slidably embracing the upper end portion of said shaft and extending upwardly into said hopper, means for directly transmitting rotation of said shaft to said elongated member, said means allowing sliding movement of said elongated member upon said shaft, a spring means for yieldingly holding said elongated member in one direction of its slidable movement on said shaft, a control plate on said elongated member and below said hopper, and at least one material engaging arm on said elongated member and positioned in said hopper.

3. In combination, a storage material building having an opening in its upper area, a vertical. tubular housing secured to said building and associated with its opening, a vertical shaft rotatably mounted in said tubular housing, a spoked pulley wheel secured to the lower end of said shaft, material engaging bar fins on the spokes of said pulley wheel, a prime mover having a drive shaft, a pulley wheel on said drive shaft, an endless belt embracing said two pulley Wheels, a hopper having an open bottom in the upper portion of said housing, an elongated member slidably embracing the upper end portion of said shaft and extending upwardly into said hopper, means for directly transmitting rotation of said shaft to said elongated member, said means allowing sliding movement of said elongated member upon said shaft, a spring means for yieldingly holding said elongated member in one direction of its slidable movement on said shaft, a control plate on said elongated member and below said hopper, and at least one material engaging arm vertically adjustable on said elongated member and positioned in said hopper.

4. In combination, a storage material building having an opening in its upper area, a vertical tubular housing secured to said building and associated with its opening, a vertical shaft rotatably mounted in said tubular housing, a spoked pulley Wheel secured to the lower end of said shaft, material engaging bar fins longitudinally adjustable on the spokes of said pulley wheel a prime mover having a drive shaft, a pulley wheel on said drive shaft, an endless belt embracing said two pulley wheels, a hopper having an open bottom in the upper portion ofA said housing, an elongated member slidably embracing the upper end portion of said shaft and extending upwardly into said hopper, means for directly transmitting rotation of said shaft to said elongated member, said means allowing sliding movement of said elongated member upon said shaft, a spring means for yieldingly holding said elongated member in one direction of its slidable movement on said shaft, a control plate on said elongated member and below said hopper, and at least one material engaging arm on said elongated member and positioned in said hopper.

5. In combination, a storage material building having an opening in its upper area, a vertical tubular housing secured to said building and associated with its opening, a vertical shaft rotatably mounted in said tubular housing, a spoked pulley wheel secured to the lower end of said shaft, material engaging bar tins on the spokes of said pulley wheel, a prime mover having a drive shaft, a pulley Wheel on said drive shaft, an endless belt embracing said two pulley wheels, a hopper having an open bottom in the upper portion of said housing, an elongated member slidably embracing the upper end portion of said shaft and extending upwardly into said hopper, means for directly transmitting rotation of said shaft to said elongated member, said means allowing sliding movement of said elongated member upon said shaft, a spring means for yieldingly holding said elongated member in one direction of its slidable movement on said shaft, a control plate on said elongated member and below said hopper, and at least one material engaging arm on said elongated member and positioned in said hopper; at least one of said material engaging bar fins being vertically angularly adjustable relative to the pulley wheel spoke to which it is secured.

6. In combination, a storage material building having an opening in its upper area, a vertical tubular housing secured to said building and associated with its opening, a vertical shaft rotatably mounted in said tubular housing, a spoked pulley wheel secured to the lower end of said shaft, material engaging bar fins on the spokes of said pulley wheel, a prime mover having a drive shaft, a

7 pulley wheel on said drive shaft, an endless belt embracing said two pulley Wheels, a hopper having an open bottom in the upper portion of said housing, an elongated member slidably embracing the upper end portion of said shaft andextending upwardly into said hopper, means for4 directly transmitting rotation of said shaft to said elongated member, said means allowing sliding movement of said elongated member upon said shaft, a spring means for yieldingly holding said elongated member in one direction of its slidable movement on said shaft, a control plate on -said elongated member and below said hopper, at least one material engaging arm on said elongated member and positioned in said hopper,l and a downwardly'and outwardly extendingilangeon at least one of said bar fins. 1 7. In combination, a storage material building having an opening in itsupper area, a vertical tubular housing. secured to said building and associated rwithyits opening.

a vertical shaft rotatably mounted in said' tubularlhousL ing, a spoked pulley wheel secured to theilowerfendof said shaft, material engaging -bar tins on `the'fspokes 'ojf said pulley wheel, a prime mover havingfafdrive' shaft, p,

a pulley Wheel on said drive shaft, an endless belt'` ern-v bracing said two pulley wheels, a hopper havinganfjopem Y bottom Vin the. upper 'portion' ofV said yhousing,anluelon-- gated member slidably -embracingftheiupp'er'endportion of said shaft and extending upwardlyinto 'said hopper,

means for directly transmitting rotationl of said shaV said elongated member, said means allowing movement of said elongated member uponsaidshaft,

a spring means -for yieldingly holding said elongated member in one -direction of its slidable movement 'onfsaid v shaft, a control plate `on said elongated member 1an below said hopper, at least 'one material engaging -a n on said elongated member and positioned in saidphop` means Ifor shifting the position of 'said'prime moverrel tive to said spoked. pulley wheel, and a belt loop'braeket substantially embracing said endless belt and operar"l ly secured to said tubular housing. i

8. In combination, a storage'r'naterial building ha an openingl in its upper area, avertical tubular housing secured to said building and associated with its opening', a vertical shaft rotatably mounted Vin said tubular hou ing, a spoked pulley,wheel secured to the lower: of said shaft, material engaging bar fins on the spoke said pulley wheel, a prime mover having a drive shaj a pulley Iwheel on said drive shaft, an endless beltje'n ing, a spoked pulley wheel secured to the lower end of said shaft, material engaging bar ns on the spokes of said pulley wheel, a prime mover having a drive shaft, a pulley wheel on said drive shaft, an endless belt ernbracing said two pulley wheels, a hopper having an open bottom in the upper portion of said housing, an elongated member slidably embracing the upper end portion of said shaft and extending upwardly into said hopper, means for directly transmitting rotation of said shaft to said elongated member, said means allowing sliding movement of said elongated member upon said shaft, a spring means for yieldingly holding said elongated member in one direction of its slidable movement on said shaft, a control plate on said elongated member and below said hopper, and at least one material engaging arm on said elongated member and positioned in said hopper; said hopper being spaced apart from the inside of said tubular housing.

10. In combination, a storage material building having an opening in its upper area, a vertical tubular housing secured to said building and associated with its opening, vertically adjustable hook arms on said tubular housing for engaging said building and suspending said tubular housing in said building below the opening in the upper ythe lower end of said shaft, material engaging bar iins on [the spokes of said pulley wheel, a prime mover having l a drive shaft, a pulley wheel on said drive shaft, an endless belt embracing said two pulley wheels, a hopper having an open bottom in the upper portion of said housing, vran' elongated member slidably embracing the upper end `piofrtionof said shaft and extending upwardly into said hopper, means for directly transmitting rotation of said shaft to "said elongated member, said means allowing slidbottom in the' upper portionof said housing, an elongated` member slidably embracing the upper end portio'rrpfelongated member, said means allowing sliding move-V ment of said elongated member upon said shaft, a spring means for yieldingly holding said elongated member in one direction of its slidable movement on said shaft, a control plate on said elongated member and below Vsaid hopper, at least one material engaging arm on said elongated member and positioned in said hopper, means for shifting the position of said prime mover relative to lsaid spoked pulley wheel, and a belt loop bracket substantially embracing said endless belt and operatively'secured to said tubular housing; part of said belt loop extending into the groove of said spoked pulley wheel or clearing said groove of undesirable foreign matter.

9. In combination, a storage material building having an openingin its upper area, arvertical tubular housing secured to said building and associated with its opening, a 'vertical shaft rotatably mounted in said tubular housrfing-[movement of said elongated member upon said shaft, a spring means Ifor yieldingly holding said elongated meinber-1in one direction of its slidable movement on said shaft, a ''ontrol plate on said elongated member and below said zhop'per, and at least one material engaging arm on said 4rd elongated member and positioned in said hopper.

1.17. ln'co'mbination, a'storage` material building hav- .ingan opening in its upper area, a vertical tubular hous- 'ing securedto said building and associated with its opening, javertical shaft rotatably mounted in said tubular housing, a spoked pulley wheel securedto'the lower end 'of'said shaft; material engaging bar iinson the spokes of said pulley wheel, a prime mover `havingra drive shaft, bracing saidtwo pulley wheels, a hopper having anopen; j f

Ia' .pulley wheel on said drive4 shaft, an endless belt embracing said two pulley wheels, a hopper having an open bottomin'the upper portion of said housing, an auger thread on the upper portion of said vertical shaft, an

-elongated'member rotatably slidably embracing the upper portion of *said vertical shaft and extending upwardly into said hopper, pins extending through said an elongated memberv and in engagement with the auger thread on said vertical shaft, a coil spring in said an elongated member having one end engaging said an elongated member and its other end yieldingly engaging the top end of said vertical shaft, a material control plate on said an elongated member and below said hopper, and at least one material engaging member on said an elongated member Vand positioned Within said hopper.

References Cited in the tile of this patent Donelson Apr. 18, 1961

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