US1899528A - Sand blast tank apparatus - Google Patents

Description

F b- 28, 9 3- w. A. ROSENBERGER 1,399,528

SAND BLAST TANK APPARATUS Filed Aug. 18, 1928 3 Sheets-Sheet -1 n I"? n Feb. 28, 1933. w. A. ROSENBERG-ER 1,899,528

SAND BLAST TANK APPARATUS Filed Aug. 18, 1928 3 Sheets-Sheet 2 Feb. 28, 1933.

W. ROSENBERGER .SAND BLAST TANK APPARATUS Filed Aug. 18, 1928 3 Sheets-Sheet 3 dummy Patented Feb. 28, 1933 UNITED STATES PATENT OFFICEF- WILLIAM A. ROSENBERGER, oFnAGE-Rsrown, MARYLAND, Assrenon 'ro ranenoan' CORPORATION, or HAGERSTOWN, MARYLAND, a conrona'rron or MARYLAND SAND BLAST TANK APPARATUS Application filed Aug ust 18, 1928. Serial No. '300,578

connected as to be also utilized as means for r separating the abrasive particles from the air when the pressure in the tank is dlscharged for any purpose, as in refilling with abrasive,

and the device may further include means it for protecting'the separator element from the action of the abrasiveas it is projected against the separator by the air as it escapes from the tank through the separator.

The apparatusalso includes improvedmeans for controlling the discharge of the abrasive and regulating the abrasive flow w th extreme accuracy, the same being adapted to prevent clogging of the abrasive as it passes through the regulating passages or orifices.

In the accompanying drawings Figure 1 is a side elevation of a small sand blast tank of the portable type equipped in accordance with the invention.

Figure 2 is a top plan view of the same;

Figure 3 is a vertical section through the bottom of the tankand controller valve casting on the axis of the controller valve;

Figure 4 is a section on the line Jr-4 Figure 3.

Figure 5 is a top plan view of the right hand 5 end of the controller valve as seen in Figure 3,

the same being shown in this figure as disconnected fromthe tank.

Figure 6 is a perspective view of the eccentrioally apertured valve bushing. Figure 7 is a diagrammatic plan of the abrasive passage and valve, the valvecasting being broken away. 7

Figure 8 is a fragmentary perspective view of the controller valve removed from the valve seat. 1 V

Figure 9 is a vertical cross section showing the water and abrasive separator. V

Figure 10 is a horizontal cross section on the line 1010 of Figure 9.

Figure 11 is a plan of the controller valve,

the portion at the left being broken away and I shown insection onthe line 1111 of Figure 3.

Referring to the drawings by numerals, each of which isused to indicate the same or similar parts in the differentfigures, the machine,'as shown, comprises a. sand blast pres sure tank 1 which, as-shown, is preferably of the small portable variety to which the features of the invention are particularly adapted, though they are capable ofmore general application. Y J y The, tank 1 is provided with a fillervalve 2 at the top for the admission of abrasive, air under pressure being-suppliedby way of an air pressure pipe 3 to the. separator 4, which 1 v separator 4 is connected by a short nipple5 to the inside of the tank near the top and-by a drop pipe 6 to the abrasive mixing and controlling valve 7 atthe side by wayof a passage 8, see particularly Figure 4, the con-. troller valve, in turn, being connected in'a manner to be described, to the bottom of the tank at 9 to receive abrasive therefrorin The controlling and mixing valve 7 is, in turn, connected by way of a flexible hose 10 to a suitable abrasive projecting nozzle .11.

. Referring more particularly to the details of the structure, the valve 2 for the admission of abrasive is, in the preferred form of the invention shown, held in position by a screw handle 15 which has a threaded engagoment with a yoke 16, which yoke is removably secured in position on the tank by means of belts or studs 17 having heads 18 spaced upwardly above the tank, the yoke having open slots to receive the bolts.

The slot 19, Figure 2, in the form of the invention shown, is open at one endof the yoke and the slot 20 is open at the side near the other'end. The handle '15 has a screw threaded shank 21 which has a threaded engagement with the yoke and the end of the screw may engage the cover in any suitable manner.

The air pressure pipe 3, in the form of the invention shown, is provided with a three way valve 25, see Figure 1 which, in the different positions of the ,val'vefconn'ects the pressure pipe 3to the tank and to the mixer valve 7 through the separator 4 and in the other position of the valve closes the pressure pipe 3 and connects the tank 1 and the mixer valve 7 to the open air by way of the separator 4. 1

The separator 4: comprises a separator member 27,. also referred to as a separator barrel, in the form of a tubular member which, in the preferred form of the invention shown, is composed of several layers of Wire cloth. This barrel or separator member, as shown, extends the full length of the separator casing 28. It encloses the end of the air inlet 29 at the top inside the casing 28 and the end of the drip discharge 30 at the bottom, the end referred to being also at the inside of the casing. The casing 28, as shown, consists of a tubular member 31 enclosingthe separator member. This is closed at the top by a cap 32 through the center of which the connection 29 is passed,-and it is closed at the bottom, in the form of the invention shown, by a fitting 33 which may be also referred to in its complete form as a cap, but which, in the form of the invention shown, is a reducing fitting enclosing with its upper portion the lower end 34 of the tubular member 28 of the casing, the said fitting being, in turn, closed at its lower end by a plug 35 which is hollowed out to receive the lower end of the separator barrel 27 and is further bored and tapped at 36 at its lower end at the center to receive the drip cock 37. The separator barrel 27 is encircled opposite the. nipple 5 which connects the separator to the tank and the connection 38 which connects the separator to the drop pipe 6 which leads to the mixing valve by a shield shown in theform of a plate ring 39 which protects the-separator member or barrel 27 or the wire cloth portion thereof from the abrasive particles which would otherwise be projected against the separator member when the tank is being emptied of compressed air through and by way of the separator, as already indicated and as more fully hereinafter described. 7

It will be understood that whenair is admitted from the'pressure pipe 3 through the nipple 29 at the top of the separator, it is discharged within theseparator inside the separator barrel 27 and passing outwardly through the multiple screen the moisture is rubbed out ofthe air by contactwith the screen. This effect is increased by the tendency to expansionof the air from the pressure in the pipe 3 to the pressure within the tank 1 causing cooling and condensation.

The moisture thus collected runs down inside the tubular separator member 27 and collects at the bottom of the casing 28 in the cap or fitting 33 from which it is removed at the will of the operator by opening the drip cook 37.

The reverse operation of the separator is of considerable importance. When new abrasive is to be supplied the three-way valve 25 is first turned to release the air under pres sure in the tank through the opening 26 leading from the valve to the outside air, the pressure pipe. 3 is at the same time closed. In passing through the separator, which it enters from the tank mainly by way of the nipple 5, and drop pipe 6 and the fitting 38, the air is projected directly against the shield 39 and owing to the high velocity which it attains and to the boiling of the abrasive in the tank due to the release of the pressure, a

considerable amount of abrasive is carried by the escaping air into the separator where it comes in contact with the shield 39 and is depositedin the separator. Part of the abrasive thus deposited is returned to the tank by the reverse air current during the subsequent filling of the tank with air and any which accumulates innthe separator maybe discharged by way ofthe bottom plug 35, which may be removed for this purpose.

By the action-of the separator 4, removing the abrasive from the air during the discharge of the latter-from the tank prior to filling, the destructive action of the abrasive on the three-way valve 25 through which it must pass in the absence of the separator, is practically eliminated and in this way an extremely troublesome sourceof replacements is removed or, at least, the necessity for replacements is so reduced as to have substantially this effect.

Other features of importance relate to the construction and operation of the mixing and controllingvalve and other details at the bottom of the machine which contribute to the production of accurate control and easy adjustment of the stream, making it possible to use extremelyfine'nozzles down to those as small as three sixty-fourths of an inch. The features of this part. of the machine also include an arrangement whereby it is made possible to handle a fine stream of abrasive, as described, without clogging.

The construction also includes a new form of valve which not only contributes to accuracy of adjustment, but to the length of life of the assembled device, in that it not only presents to the abrasive a shut ofi edge of material which withstands the abrasive action to the best advantage, but provides for four of such edges which can be used alternatively, increasing the life of the valve member by a correspondingmultiple. The construction also provides for the instantaneous replace of the valve member.

In the form illustrated, the tank is flanged at the bottom at 40 surrounding the discharge through the tube.

any suitable manner, as by means'of bolts 42 passed throughthe flange 40 and through suitable ears 43 on the mixer valve, member 41, see particularly Figures 1, 3 and 5.

In the construction shown the discharge opening 9 is slightly enlarged or chambered at 44 immedately below the mouth of'the opening 9 which chamber 44 receives and accommodates the flow control bushing or approach bushing 45, to be more particularly described. J

- The flange 40 is further chambered at 46 surrounding the chambered portion 44 near the bottom surface of the flange 40. This chamber 46 being wide and shallow to accommodate a gasket 47 between the flange 40 and the controller valve casting 41. The mixer valve casting 41 is provided near the bottom with a longitudinal air passage 48 which, as shown, and normally, is substantially horizontal.

This passage 48 is closed at one end at the left in Figure 3 and at the other end at the right it terminates in the air and abrasive mixture passage 49, which discharges into the hose 10 which is connected to the fitting 50 which is seated in the mouth of the passage 49. Leading, downwardly into the abrasive ind air mixture passage 49 is the abrasive passage 51 which, in the form of the inven-, tion shown, hasa reducing taper downward ly toward the passage 49,.being intersected by the abrasive fiow valve chamber 52,- which chamber 52 is shownin the form of a horizontal bore formed in the mixer valve member 41 which it enters from the left of the same as seen in Fi ure 3. Above the valve I b ates in the chamber 52 is a cylindrical'tubiular member, preferably formed, particularly as to its wearing surface, of high quality rubher. This valve is secured to a valve operating shaft 56 which fits inside of the tubular,

valve member 55, being secured thereto to rotate therewith by means of a pin 57 which extends diametrically through the shaft and The valve and shaft are surrounded near the open end of the chamber or bore 52 by packing 57, which is separated from the tubular valve member 55 by washers 58.. The packing and the valve and the shaft are, in turn, held in position by the packing gland member 59 which is shown. in the form of a hollow plug which is apertured at (SO-to pass the shaft 56. The gland member 59 is shown as provided with laterally extending arms 61, see particularly Figure 4, through which are passed bolts 62, see FiguresBv and 4, which bolts are seated in the valve member41 at each side of the bore 42. The gland member 59 enters the end of the bore 52, beingforced into close contact withthe packing and compressing the sarne by tightening of the bolts 62. The shaft 56 may be turned by means of an indicating wheel 64 which is secured to the end of the shaft in any suitable manner, as bymeans of a pin 65, the wheel being preferably marked with graduations66, see Figure 1, which cooperate with an'indicating pointer 67 on the valve member or casting 41 and the graduations 66 are preferably arranged in four series or scales on each side of two zero marks 74 indicating the two closed posit-ions of the valve, as hereinafter de- 7 scribed. i The valve member 55 is preferably'slotted at 70,:the slot being adapted to register in the open position of the valve with the pas- I sage 51 formed inthe casting,41for this purpose, it'being understood that t seat chamber 52 intersects the passagi51an d divides it into upper and lower portions or.

openings 51 and 51f. By rotating the'valve 55 to the position in which the slot70 regis:

ters with these openings, a passageway for the abrasive is opened from the tank 1 to the ne valve mixture or mixing passage 49.

In accordance withthe preferred construcion the slot 7 O is of the I type, or otherwise formed to present one or more inclmed closing edges 72. In the form of the invention shown, there are four of theseedges, two being presented at each of the opposite ends of the V shaped slot 70.

As willbe noted from examination of the diagrammatic view, Figure 11, the passage 51 is preferably of rectangular cross section, be ing shown as elongated so thattheinitial opening formed by the intersection of the edges 72 with the cross section of the passage is triangular, as illustrated diagrammatically in Figure 7 by dotted lines 73. i

This illustration shows a distinct advantage incident to the inclined closing edges, particularly in connection with the rectangular passage 51 having two sides parallel to the axis of the valve and two sides at right angles to it, in that it gives extremely fine regulation or adjustment as compared te would be given by closing edges parallel to the sides of the passage 51 which, in the initial opening which would otherwise be the extreme minimum of adjustment, would give Such a slotwhen of less width ice 7 initial opening being triangular in outline, can beadapted to pass an extremely small quantity of abrasive, the adjustment being capable of reduction to a point where a single line .of abrasive particles is passed through the opening at the minimum adjustment.

The construction shown, particularly in Figure 8, attains the extremely important result that it presents four closin edges 72, either one of which may be passed across the opening 5l'ahead of the remainder of the valve, inthe opening'or closing operation.

It will be easily understood that in the op-' eration of this valve there are twofully closed positions one hundred and eighty degrees apart. By marking these zero points'at 74 on the scale 66 and graduating the scale on four quadrants, i. e., on each side of each of these opposite marks 74k, a set of graduations is provided corresponding to each of the edges 72 whereby either of them may be used as the advance closing edge in opening and closing the valve and its position, i. e., the degree of opening of the valve may be indicated on the scale by means of the pointer 67.

The flow control bushing or approach bushing 45, previously referred to as seated in the chamber 44,53, is, in the form shown, novided with a passage which at the top registers with the opening 9 and which terminates at the bottom in a relatively small eccentrically located discharge opening 76. The bushing, see particularly Figure 6, is formed -with diametrically opposite key notches-7T which are adaptedto engage the key projection 7 8011 the valve member 41 so that the bushing can be seated in two diametrically opposite positions of adjustment, being raised for which purpose the member 41 must be disconnected from the tank 1 and rotated through an angle of one hundred and eighty degrees from one position to the other.

In the position shown, the discharge opening 76 is spaced by about one-third of the diameter of openin '76 out of registration relatively to the passage 51and in'the opposite position in which the other notch 2'7 engages the key projection 78, the discharge opening-76 will register accurately with the passage 51. This gives what may be termed a primary flow control of the abrasive from the tank 1 to the valve.

- A further object of the construction shown as to the bushing l5 and the passage therethrough, consists in the means for preventing cloggingof the opening 76, 51, by and with abrasive. This is accomplished by making the incline of the tapered passage 75 steeper on one side, i. e., at 79, than it is on the other side at whereby the particles approaching the discharge opening 76 are given a different rate of speed, i. e., faster on the side 79 and slower on the side 80, so that the tendency to clog is overcome by the tendency thus created to-rotate the particles on one side the fiow is controlled about the particles onthe other side. The rolling orrotating effect thus accomplished prevents, or greatly reduces, the tendency to clog the opening.

The operation has been quite fully explained in connection with the description of the'machine. WVhen air is admitted to the tank from the pressure pipe 3 the moisture is removed by rubbing as the air expands or passes outwardly through the multiple screen 27, enteringithe tank by way of the connection-5 and being supplied to the mixer valve by way of the drop pipe 6 and lateral passage 8, F igured, leading to the air passage 48 and the mixing passage 49.

An important result is attained when the airisdischarged from the tank to reduce the pressure therein in order to admit a new supply of abrasive. For this purpose the threeway valvei25 is turned to a position in which the top or" the separator is connected by the passage 29 and a outside air by way of the three-way valve, the pressure side of the three-Way valve 25 being closed. This causes the air to leave'the tank by way of the passage 5, the air from the tank being discharged into the separator against the shield 39 byway of the fitting or nipple 5. A considerable amount of abrasive is carried by the air which is thus discharged, due to the boiling of the abrasive in the-tank incident to the drop of pressure therein. This abrasive is separated from the out-flow ing air-by the separator barrel 27 so that air which is practically free of abrasive is dis charged by way of the fitting 29 to the air pressure pipe 3, being released through the three-way valve 25.

An important difficulty with this type of apparatus in the past has resulted from the quick destruction of the three-way valves due to the necessity for passing abrasive through it when the tank was emptied of air. This difficulty is completely overcome by the use and arrangement of the separator in the manner described.

Regarding the control valve. mechanism, primarily by the adjust? ment of the flow control bushing 45. In this way the discharge opening'76 of the bushing is either placed in registration with the passage 51, giving the maximum flow, or it is placed off-center, as shown in Figure 3, whereby'the flow of abrasive is reduced in the first instance to about fifty percent of the maximum, depending on the adjustment of the abrasive flow valve 52 to be most used.

The eflect of the variation of incline on the diiferent sides of the opening 75 in the bushing and 7 9 and 80, has been fully explained portion of the pipe 3 to the whereby the particles on the opposite sides The fine adjustment of the abrasive stream,

or more particularly of the supply of abrasive l fed to the mixing valve to be mingled with the air blast, is obtained by means of the abrasive flow valve 52 which also serves as a shut-0E valve to give a complete cessation of the supply of abrasive and a double seal of the passage 51. V

In either one of the zero positions, i. e., when either of the zero points 7a on the indicator wheel 64 is in line with the pointer 67,

slot with a resulting fine regulation of the stream at and near the minimum flow, has

also been fully explained.

Still another important point resides in the easy and convenient manner in which the valve may be removed and replaced. This is accomplished by removing the bolts 62 which hold the packing gland 59 around the valve shaft 56 when the valve with the packing 57 and the shaft 56 may be removed. A new valve may be immediately substituted on the shaft 56 by removing the pin 57 and the new valve as instantaneously replaced.

I have thus described specifically and in detail a sand blast apparatus embodying the features of my invention in the preferred form in order that the nature and operation of the same may be clearly understood, however, the specific terms herein are used descriptively rather than in a limiting sense, the

scope of the invention being defined in the claims.

What I claim as new and desire to secure by Letters Patent is:

1. The combination with a sand blast tank of a mixing valve, a passage connecting the tank to the valve to supply abrasive to the valve from the tank by gravity, a tapered bushing having an eccentric opening fOI'IIl. ing part of said passage the bushing having a restricted area about its bottom portion, means for reliei ing the pressure on the particles immediately below said restricted area, means for positively locating the bushing in a plurality of positions whereby the relation of the passage in the bushing to the remainder of the passage is varied varying the size of the opening and regulating the flow of abrasive from the tank to the valve and a separate control valve for further determining and regulating the supply of abrasive to the mixing valve.

hence the supply of abrasive 2. The combination with afsand blast tank and an abrasive mixing valve with a passage leading the abrasive from the tank to the valve by gravity, a bushing having an opening with a downwardly reducing taper forming part of said passage, the lower end of the opening being eccentri'cally located, the tapered portion having a steeper angle of inclina-tion at one side than] the other, and means for locating-the bushing in a plurality ofpositions, varying as to angularlyof the bushing about a vertical axis, in one ofwhich the lower end of the opening in the bushing registers with the remainder of the passage more-nearly than in another position, where by the effective size of the opening and the. flow of-the abrasive maybe regulated.- 1

8. The combination with sand blast tank and an'abrasive mixingvalve, the structure including a passage leading the abrasive from the tank to the valveby gravity, the passage comprising a stationary restricted opening and a bushing having anopening with a downwardly reducing taper, the lower end of the opening being eccentrically lo cated and the tapered portion having a steep er angle of inclination at one side than the other, and means for locating the bushing in a plurality of positions in one of which the lower 'end of the opening in the bushing reg= isters with the restricted opening more nearly than in another position whereby the ef-,

fective size of the opening and the flow of the abrasive may be regulated, the variation of the incline tending to prevent clogging of the opening.

4. The combination with a sand blast tank of amixing valve and a passage leading abrasive from the tank to the valveand means for regulating the flow of abrasive through the passage comprising a cylindrical valve member of rubberlike material, a cylindrical seating chamber intersecting the passage, so that the plug extends transversely to said passage, means adapted for manual engagement to rotate the valve member at the will of theoperator, the end portion of the valve occupying the portion of the chamber which intersects the passage and said portion of the valve having a V slot, which in one angu lar position of the valve registers with the passage, in which position the valve is open, the V slot in another position of the valve standing at right angles to the .directionof the passage in which position the valve is closed,

advancedacross the passage to regulate the size of the same.

5. The combination with a sand blast tank the flow of abrasive comprising a sectioniof cylindrical 1 tubing of rubbenlike material, a cylindrical seating A chamber intersecting the ;passage,the tubularisection'fitting the said :chamber which is arranged so that; the tubuilar section extends transversely of the passage, means-adapted IEOIl I I1 2LI1U2Ll engagement torotate the valve member, said manually engageablevmeans having a pin adapted to enter the tubular section axially (from one end, said 'pin being provided With-means for, lfastenlngthc tubularisection and-positioning i-tzagainstrotation relatively thereto causing I it to rotate therewith; the-end portion of the:

- valve opposite-to the manually engageable -member' which occupies thesportion ofvthe I "chamber which intersects the passage having ---.ters-.with-the passagcuin which'position the a V slot whioh-imone angularepositionsrlegisvalve is open zthe- V slot: in another position lflofsthe valveextending at' night angles to: the

position :of: thepassage; in which position the valveis closecl5,lthe intersection of the Vaslot Withthe-cylindrical surface of the-valve providing four. inclined edges citherone of which 5:ma --be:advanced-acrossthe assa etore u- Si-gn-edby me at. I Hagerstovvn Maryland,

this :27 daylof Ju1 ,;1928.

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