US2518811A

US2518811A - Cement gun

Info

Publication number: US2518811A
Application number: US712458A
Authority: US
Inventors: Benjamin P Nicholson
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-11-26
Filing date: 1946-11-26
Publication date: 1950-08-15
Anticipated expiration: 1967-08-15

Description

Filed Nov. 26, 1946 2 Sheets-Sheet 1 Dry MIX 35 21 31 To Nozz/e T I a I 3 w If "I (I a Water I To Nozzle I 3nnentor jig 1 BENJAMIN P NICHOLSON (Ittornegs .A s- 5 B. P. NICHOLSON 2,518,811

CEMENT GUN Filed Nov; 26, 1946 f 2 Sheets-Sheet 2 Molgtened MIX lhwenter BENJAMIN P. NICHOLSON Patented Aug. 15, 1956 5 H-Gi"% 1 UN [TED v"S TATES FATE OFFICE ,-2,51s,s11; i

Benj' mm icholson; Seattle, Wash;

, Application lflog pgper 26, 1946;"Serial No; 712,458

"5 Claims. (01. 302-53) i m :1 ja i: 1'; '1 21v 'o'f smalrvolume, and a mass of inadequately 'hy= fi-rated or imperfectly mixed mixtureforms' a' potentially leaky-sand pocket. On the other 'han'dI m-ixture wh'ich is over1y'-hydrated' will not stick, but runs out,"not only Wasting material ldlit :onstitutin'g a potential leakl Only a homog'eneous' iniiiture wet enough to "stick when it hitsf-but dr'y em'righ 'to' giveoff a little dust and ,tureaof fin t, j, q to=harden at o'i'i''e' siifiiciently'thatpnes fin'ge'r ipr,ferf"djratiajjltf ustb'eii iVered from cannot dent itg wilrordinarily'fulfill the require;- g'i pe'lg b we? ofaic nd" flto a Y'ZZ19 'a 't mentsinthis field'of use. The amount-0f w'ater a ti ehdhofithe conduih'pthefejto beimme. i's so 'critieal, ifi ratio -to the cement'mixture, mt in Small YQlPflie and that'thedehve'ryrate of th'e'iatter must becon Q1nt1"between"tW0 stant' -in. -order that thewa'ter delivery rate at Thefd elivery must be the n'ozz an be adjusted precisely to correi'all'y instantaneous flout-off spondpfi 5' a fi 4 any. wastage ofimaterial, j'issince'thevolunie required'ima pipe jQintfiS' ver-ufi ills, inust b, 'k tdthe very small, low-volume delivery is necessary, forother g'q fs W thout [Sayin ifi at en v wise the material willz be wasted, and improperly eliflered'inust'be'aidquatflyand'unidirected and placed. Low pressure delivery is I dr 'alted, j et nwmanmtne;mixture de-. requiredfor. similar. reasons, and to avoid splash 95thatfitlgivesofisome back, in ';the-face ofthehnozzle 'man, such as 'is not only ipjuriousmo'him but prevents himufrom seeing. what he is 1 doing. Low pressure delivery ,aisoreduces the cost and=weightof therequired QQmPIQSQ ZDW jntmqt t g a resu Prompt and inter inittenficut-offand resumm tion of deljvery also less-ens waste, for. the nozzle .7 i i frequently;;:c-hange,--,hisposition orvthedirection Mechamcaily, 1t 1s], desirable tosefinploy' air, pf.his delivery-, :1.iliurin sall.such times he should preferably ,atlbwg ressure, as tl'i vehicle for out 01f delivery, but unless he can cut ofif whenfian's'portifigthriiiiitiirethrouhthe'fiondfiit and eyer desired andresurnegnt once, he must-conttl nbz'zl yetmur mate thearndunt of tinue the deliverm either,avertin andwastingdt, theiairfstream; and the'.-fnanner.of gr buildingungunwantedmthickness about-.-,-the fa ppllcatl iin :bfjth stre'am" 130,," the" mixture, jpint At; the tinre, during cut off no; mix arficmanyetmapemt. r piclgj up, 'finsueh pure. should j-remain in themgonduit where'it densit orrate f'of delivery is might settleand b e hard topick up again,-a;nd ofinteir riiption of its advance where-itmight createan obstruction and uneven hrpugh 'thecondui't ,nfqr piling at the jn'ozzle, 40 feed,,o r eyen gradua11y;,-set up and harden; The andthe homogeneity'iofj;the mixture remains cut, off,. therr,'musit;.be so,re1ated to the, delivery constant. "jIt is;aisohrfiarahle thatfmovingelee astoattain theser end's, :9. tiant l ,.,e i ina edtptliegh gh ,fleereepos qp m c on h sibleyparticularly atthe hopper. or moy inguparts, espec ally The attainme rrtg 'oflt 'aboveqBndshonstitute 5 parts, atthe.,h'opper, forit isvdifiicult'tb the prinpipal objec s ogt s' en io g- Byach v i iilit i irth ,b i s a t-t i t r i ks "ifigt'themjother highlyimportant, ohjects are attheretov unless p,

tained: must be frequently shut down;

' t qnd ita' d.

moms-dry, hence the device ffb ji i fii f t9, d alsohto.create,pulsations ln deliijery ti .nozzle ate .ra qswh ch it fluc uati s p ion 9 g; 1 131 5 li-issu isimi u h mo;- s ede @MQZ QQQP in ts. ratiosmpossible clean 0 s i time man is Working in a, restricted space, and must 7 so that it will not be obstructed when work is resumed by caked cement in the passages through which the mixture must pass. The attainment of these ends are amon further objects of the present invention.

Such a machine though it should have the capacity to contain sufficient material for operation over an appreciable period, must be small, compact, and portable, or at least mobile, for it must be moved frequently, from one joint to the next, along the length of the pipe line, and it goes without saying that it must be rugged and dependable in operation. These are among fur-. ther objects of the invention.

In the particular machine which incorporates the present invention an air stream is caused 1 to move through a space within a hopper or through a cavity in the bottom of thesupply of cement mixture in such a hopper, forthe purpose of picking up or segregating from the calized supply and advancing, the desired quantity towards the nozzle. Since portions of the mixture are thus segregated from the localized supply, to be lifted by the air stream, and thus are carried through an outlet which is above the level of the localized supply, and the rate of supply of the mixture will tend to vary if the air stream moves in a changed relationship to the localized supply, or must lift the segregated portions b varying distances above the surface of the localized supply, it is an object of the invention to maintain without material variation the level of the localized supply relative to the outlet and to the air inlet or inlets, and in particular to supply decrements from the localized supply by addition of like amounts from the main supply, yet without oversupply to the localized supply.

With these and other objects in mind, and especially such as pertain to the mechanical arrangement, as will appear more particularly hereafter, the present invention comprises the novel method, as shown in the accompanying drawings in an illustrative form, and as will be hereinafter more particularly pointed out and defined.

Figure 1 is a general vertical sectional view through the apparatus, and Figure 2 is a plan view of the same, with the hopper shown in section. I

Figures 3 and 4 are horizontal sectional views on the respective lines indicated at 3-3 and 44 of Figure 1.

The dry cement mixture, consisting of cement and line sand, is contained within a hopper I, having the usual sloping or conical bottom [0.

The hopper should be large enough to furnish a small but continuous supply over an appreciable period. Its top ll has a filler opening, to which leads a chute l2, and during operation this is closed by a closure plate 14, operable by the handle [5. The closure plate I4 is preferably conical in shape, serving to distribute the materials entering by the chute 12 toward the outside walls of the hopper. Suitable sealing means may be employed, if required, so that the interior of the hopper may be maintained under pressure. A pressure relief valve I6 prevents over-pressurization.

The bottom of the hopper is closed by a conical collar ll, which preferably is removable for cleaning, and by a removable cap plate 18. The entire hopp r'is mounted upon wheels 9, and may be supported additionally by a leg 90. Thus it may be transported from place to place, at least ,coned, to support the central mass and to afford restricted communication through the gap 2|, from the main supply into the cavity 22 beneath the spreader.

From this cavity leads the outlet 3, and it is particularly to be noted that this outlet is upwardly directed within and above the bottom ID of the hopper, and thence leads outwardly at 30 to an exterior connection at 3|. From this point to the nozzle '8 the mixture is transported by any suitable means, such as the flexible hose 8 l. Such nozzles are known, and while the particular form of the nozzle and the hose are not in themselves part of the present invention, the manner in which uniformity of hydration at the nozzle is achieved by the general combination is considered to be part of the invention. In order to terminate or to initiate the passage of the cement mixture from the hopper to the nozzle Iprovide preferably a cut-off valve, in the nature of a plug 33, which is guided in the cap S8 for upward movement, but which is normally held open, against spring tension tending to close it. Any suitable mechanism to these ends may be employed, and the connection shown includes a lever 34, a link 35, a sprin 36 tending to close the valve 33, and a cam 31 pivoted to the rod 35 at 38, and riding upon a shelf l9. When the cam 3'! is thrown to the left, as viewed in Figure 1, by the handle 39, the spring 36 will effect immediate closure of the valve 33, whereas in the position shown the valve is held open. The cut-01f occurs at the hopper outlet, within the hopper, not in the hose line nor at the nozzle, hence there is no accumulation in the latter of mixture WhlCh-Wll]. disturb subsequent uniformity of delivery.

Air under low pressure, perhaps 35 pounds per square inch, is used as a vehicle to pick up the dry cement mixture within the cavity 22, and to lift and deliver it through the outlet 3 towards the nozzle'8. Air is supplied under pressure at i, and since the air must be dry, in order that it will not tend to moisten the dry mixture within the hopper, it is preferably passed immediately through a dehumidifier 49, whence it issues at 4|. It passes thence through a pressure regulator 42, and the air is supplied to the hopper by way of a branch 43, and past a cutoff valve 44, to a connection at 45, externally of the collar ll. A branch 48, within the hopper, supplies the same pressure to the hopper above the, main supply'of mixture therein.

The collar H is formed with passages leading from its inlet 45 to the interior at the tangentially directed ports 46. These are located within thecavity 22, that is, below the spreader 2, yet somewhat above the level of the cavitys bottom, or of material segregated therein, and in the vicinity of the outlet 3. Air under pressure, entering past the valve 44, as controlled by the pressure regulator 42 and as indicated by the gauge 41, enters the'cavity tangentially at asrsgen points efig-ularly spaced; whirls-i thereabout, and since the localized supply of dry mixture within cavityis li'mited inquantity; it picks upa portion *of this mixture-and carries it by 'way o1 the centrally disposed andupwardly directed outlet 3, which istheon-ly outlet-from the cavity, and thence. byway of the. passage ill, and the hose 81, to the nozzle 8; The portion so-delivered simultaneously replaced by material entering the cavity ZE-from above through the restricted opening 2|, assisted by air pressure above the main supply, hence the operation:-is-continuous so longa's any 'mixture remainsintm hopper. The instantaneous amount of material in the cavity i l remains quite constant; decrements being immediately replaced from the main supp]y,.a,bove. Ll 1m, .5 I It isnecessary, ofcourse,r that water-be supplied in-order to hydratethe dry mixture which is -delivered at the nozzle.-

While the manner of supplying this-water -might -be any suitable arrangement, still the arrangement shown is particularly advantageousin conjunction with the present mechanism. Water 'from aconvenient source issupplied at 5, and-preferably -is filtered at 50, in orderto remove-any sediment that might tend to block" the "very-smallneedleaperturesby which itis discharged at thenozzle. It passes thence, by-the conduit 5| and hose 52, directly. to -the nozzle. A regulating valve 53 should beemployed here, forhere the amount of rwater supplied, in -ratio to the rather constant rate "of" delivery of -mixture, is-controlled. -A normally closed manual-pressure-released .-valve 54 controls its discharge atthe -nozzle-,---to mix with the emerging-dry mixture, or its cut-off when delivery of mixtureis-cut off; It is important that a minimum-quantity of water be supplied, just sufiicient for chemical admixture with-the cement, and in fact best results are obtained if the mixture, when it emerges, is dry enough that some cement dust is given off. It islialso desired to point out; that the-arrangement afiords very fine control of the ratiouot cement mixture to the water,--for the'uniformity and continuity of the supply of mixture matches the uniformity of the continuous water supply, and. thevalve; at *53 'need'bnly regulate the ratio, rather than to'attempt therebr at the valve 54 to'attempt'to match water supply to fluctuations in quantity of 'mixture supplied. In some operations it may b'ene'cessaryto supply, for partfof tliejob, a drier or awetter mix than forother partso'f the same job, and this is done'simply by closing or opening the valve 53 more or less, knowingthat the'quantity of mixture supplied will remain constant at all'times.

. In order that the interior of the device may be maintainedidry at all times, it may be cleaned byl a blast of dry air. The air supply line -be a bypass 62, clean-out air enters the connection 0f a eavity- -at EZ- i's-ofgreat importance to the successful operation of this device, and-01 the carrying out of the process i-volvedl- Within this-cavity is segregated a small localized supply of -the mixture, in *such iorm' -and so loosened from the main mass that it may readily vbe picked up by the air current-entering tangentially at 46;- and be carried thereby in uniform suppl'y to the nozzle; Asthe materialis thus' carried =out by the air current, new material continuously entersthrough the restricted gap at 2i, to take its? place? The operation is continuous so long ='as anymixtu're remains in the hopper; arid, :beeausethe operation canbe closely controlled to deliv'er small, uniforrn'amounts, COII'GCtlYcx-HY- -d-rated; operation can" c'ontinue' over very: appreciable periods, withoutwastage, before the hopper -'-must'be recharged. Moreover; the-nature of the arrangement is such' thatthe -material which enters-the hopper; though it may pile up elround the' 'outsidef walls initially, will not continue to cavitate through its axi'al core, but by" reason er the peripheral arrangement of the gap at it, and" the conical nature of the spreader at 2 such cavitation is prevented, land thereby there "is maintained, when the supply gets low, a substantially uniform thickness of-material to prevent any blowing outof pressure 'from'the c "ity.

1 claim asmyinventidn: 'i "'fLIn chamsmrer continuously supplyin a -ptilve'rulent mixtiire "iii diy stat'eandfiri' regu- Tat'ed quantitiesifthro'u'gh an outlet. connected ndzzlefa closd' cylindrical hopper' haviiig a substantially colle shp d bottomiall lfllfr t d conical spreader coaxially disposed I inf, said 116p- ;per'.' in v, vertic'ally spaced (relation to the x remit of said bottomffsaid spreade "to support the central ma'ssiof material said w a e i em' iauhai we were m p am c ni a were: 3. beni i uiel ed e f d s r r b t re ab i h l mi ed. c mm ni atie s ai chamb rs a. u ceuz fuq pressesl a ga ura i y qivannu arly pacediansential y directed airinletsin the converging walls of said feeding chamber below ,said spreader, to deliver compressed; air to( said, feedingichamber, .'a mixture outlet passageway leading from said iceding chamberbelow .saidspreader and, adapted for connection tona remote nozzle, and vvalve means Within said ..feeding chamber, for controllinglthe discharge of mixture-at saidfeding chamber outlet, m X 2. In a mechanism for 'continuouslysupplying a pulverulent cement mixture in a dry state and in regulated quanties through-an outlet connected ma nozzle; a closed hopper having a substantially cone-shaped bottom, said hopper being divided into an upper main supply chambe'rand a lower feeding chamber, by an inverted eonecem auy disposed at a point' a bove the' lower 'extreir'iity of said bottom, the outer edges of said cone being arranged in spaced relation to the adjacent converging walls of said bottom to form a restricted annular passageway placing the two chambers in communication, a tangential inlet to deliver air under pressure to said feeding chamber, a mixture outlet conduit extending radially through the wall of said feeding chamber and terminating at its inner end, substantially centrally within the latter, in a downwardly directed mouth,

spaced above the. lower extremity of said feeding chamber, said outlet conduit beingadapted for connection to a nozzle, and valve means for closin said mouth.

, 3. In mechanismfor continuously supplying a pulverulent mixturein a dry state and inregulated quantities through an outlet connected to a nozzle; a closed cylindrical hopper having a substantially cone-shaped bottom, an inverted conical spreader coaxially disposed in said hopper in-vertically spaced relation to the lower extremity of said bottom, said spreader serving to support the central mass of material in said hopper andv dividing said hopper into an upper main supply chamber and a lower feeding chamber, the outer edgeof said spreader being inwardly spaced from the adjacent converging walls of said bottom to form a restricted annular throat, establishing limited communication between said chambers, a source of compressed air, a plurality of annularly spaced tangentially directed air' inlets in the converging walls of said feeding chamber below said spreader, to deliver compressed air to said feeding chamber, a mixture outlet passagewayextending radially through the converging walls of said feeding chamber below said spreader and adapted for connection to a remote nozzle, said outlet passageway termihating at its inner end, substantially within the central portion of said feeding chamber in a horizontally disp0sed"mou'th arranged at substantially right angles to the axis of said passageway and a vertically reciprocable valve within said feeding chamber for cooperation with said mouth to control the therethrough.

4. In mechanism for continuously supplying a 'pulverulent mixture in a dry state and in regulated quantities through an outlet connected to a nozzle; a closed cylindrical hopper having a substantially cone-shaped bottom, an inverted conical spreader coaxially disposed in said hopper in vertically spaced relation to the lower extremity of said bottom, said spreader serving to support the central mass of material in said hopper and dividing saidhopper into an upper main supply chamber and a lower feeding chamber, the outer edge of said spreader being inwardly spaced from the adjacent converging walls of said bottom to form a restricted annular throat, establishing limited communication between said chambers, 21- source of compressed air, a plurality of annularly spaced tangentially directed air inlets in the converging walls of said feeding chamber below said spreader, to deliver compressed air to said feeding chamber, pressure equalizing means to deliver air from said source to the upper portion of said main supply chamber, a mixture outlet passageway leading from said feeding chamber below said spreader and adapted for connection to a remote nozzle, valve means for controlling the admission of air to said feeding chamber and pressure equalizing means and valve means within said feeding chamber for controlling the discharge of mixture at said feeding chamber outlet.

discharge of mixture 8 5. Portable apparatus for continuously sup- :plying a pulverulent cement mixture in a dry state and in regulated quantities through an outlet connected toaremote nozzle, comprising a vertically disposed cylindrical body terminating at its, lower endin a depending annular apron, atransverse axle supported by said apron, wheels on said axle, a hopper in the upper portion of said body having a substantially cone-shaped bottom lying within the confines of apron, an inverted conical spreader coaxially disposed in said hopper in vertically spaced relation to the lower extremity of said bottom, said spreader serving to support the central mass of the main supply of material in said'hopper, and dividing said hopper into an upper main supply chamber and a lower feeding chamber, the outer edge of said spreader being inwardly spaced from. the adjacent converging walls of said bottom, to form .a restricted annular throat, establishing limited communication between said chambers, a source of compressed air, aplurality of annularly spaced tangentially directed air inlets in the converging walls of said feeding chamber below said spreader, an air conduit connecting said source of compressed air with said tangential inlets,;said air conduit being located in relatively close proximity to the outer wall of said body and having valve means for controlling the passage of air 'therethrough, a mixture outlet passageway extending radially through the converging wall of the feeding chamber below said spreader, and adapted for connection to a remote nozzle, valve means within said feeding chamber for controlling the discharge of mixture at said feeding chamber outlet and control means for said last named valve located externally of said body in relatively close proximit to said air control valve.

BENJAMIN P. NICHOLSON.

CES CETED The followingv references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 681,867 ---Bardwell Sept. 3, 1901 749,206 Limbert Jan. 12, 1904 834,108 Corey Oct. 23, 1906 1,142,567 Jensen June 8, 1915 1,160,283 Hay Nov. 16, 1915 1,319,193 Von Porat Oct. 21, 1919 1,433,302 Rothchild Oct. 24, 1922 1,566,517 Bergman Dec. 22, 1925 1,697,585 Barker Jan. 1, 1929 1,858,561 Ruemelin May 17, 1932 1,953,091 Westberg et a1 Apr. 3, 1934 2,072,845 Benoit Mar. 9, 1937 2,147,300 Kennedy Feb. 14, 1939 2,219,011 Kidwell et al Oct. 11, 1940 2,299,565" Colburn Oct. 20, 1942 2,327,337 Burch et al Aug. 24, 1943