US3460291A - Abrasive blasting apparatus - Google Patents

Description

159 J. H. CARPENTER ETAL 39 6 9 ABRASIVE BLASTING APPARATUS Filed April 5, 1967 4 Sheets-Sheet 1 J. H. CARPENTER ET ABRASIVE BLASTING APPARATUS 4 Sheets-Sheet 2 Filed April 3, 1967 3 m l m 1969 J. H. CARPENTER ETAL 3, 60,291

ABRASIVE BLASTING APPARATUS 4 Sheets-Sheet 5 Filed April 3, 1967 Aug. 12, 1969 CARPENTER U AL 3,460,291

ABRASIVE BLASTING APPARATUS 4 Sheets-Sheet 4.

Filed April 5, 196'? te tea US. Cl. 51-9 12 Claims ABSTRACT OF THE DISCLOSURE A boom mounted blast wheel is rotated by a motor having a relatively short shaft with substantially vertical feed tubes disposed around the motor feeding abrasive particles to the wheel. The unit includes means for moving the wheel from side to side, back and forth and up and down. The blast pattern is controlled by apertured plates disposed above the blast wheel.

Background of the invention This invention relates to an abrasive blasting apparatus for cleaning relatively inaccessible workpieces such as the inside of covered hopper cars, pipes, and tanks of various configurations.

Various attempts have been made to provide a blast arrangement for cleaning inaccessible spots. One such attempt is shown in Foster Patent 3,052,066. This arrangement, however, is limited to cleaning tubular shapes since it utilizes guide rollers which are mounted against the tubular surface being cleaned. A further attempt is shown in Lehman Patent 2,507,166. This arrangement, however, because of the inclusions of a guide or yoke, is impossible to obtain a full 360 blast coverage. A still further arrangement is shown in copending application Ser. No. 561,987, filed June 30, 1966. Although this arrangement works effectively, the motor is mounted remotely from the blast wheel which requires a relatively long shaft between the motor and blast wheel.

The various devices described above were designed to replace otherwise conventional methods. For example, in conventional methods of cleaning the inside of covered hopper cars, tanks, etc., the operators crawl into the cars or tanks and use compressed air nozzle blast guns. Such a method, however, is both slow and costly because of the labor involved. For cleaning the inside of pipes automatically a nozzle blast has been used with, however, low production.

Summary of invention An object of this invention is to provide an abrasive blasting apparatus which includes some or all of the following features. One feature is ability of the blast wheel to be inserted vertically or nearly vertically into any interior shape with the spent abrasive being able to drain out thereof or of such a shape that the abrasive can be later dumped out.

A second feature is the ability of the blast wheel to be inserted in a minimum size opening.

A further feature is the ability of the blast wheel to give full 360 blast coverage or any portion thereof.

A still further feature is to provide a boom blast wheel arrangement that does not require long line shafting between the motor and the blast Wheel.

In accordance with this invention the abrasive blasting wheel is connected by a relatively short shaft to a motor disposed adjacent to and above the wheel. Substantially vertical confined feed means leads from above the motor to the wheel. The feed means may be in the form of a plurality of coarcuate passageways with deflector mem- 3,460,291 Patented Aug. 12, 1969 bers therein for spreading the abrasive that flows therethrough. Apertured plates may be at the bottom of the passageways to permit the abrasive to flow into the impellerless blast wheel. The relative positioning of the plates with respect to each other may be controlled to in turn control the degree and pattern of abrasive fed into the blast wheel. The apparatus may be mounted in such a manner that the wheel can be moved up and down, back and forth, and to and fro. Additionally, the feeding of abrasive particles to various parts of the blast wheel may be remotely controlled and even programmed for the cleaning of particular workpieces.

Brief description of the drawing FIG. 1 is a front elevational view of an apparatus formed in accordance with this invention;

FIG. 2 is a cross-sectional view taken through FIG. 1 along the line 22;

FIG. 3 is an end view in elevation of the apparatus shown in FIGS. 1-2;

FIG. 4 is an enlarged view in elevation of a portion of the apparatus shown in FIGS. 1-3;

FIG. 5 is a cross-sectional view taken through FIG. 4 along the line 55;

FIG. 6 is a cross-sectional view taken through FIG. 5 along the line 66;

FIGS. 7-8 are plan views of alternative arrangements used in the apparatus of FIG. 6;

FIG. 9 is an elevation view of a portion of the apparatus shown in FIG. 7;

FIG. 10 is a cross-sectional view taken through FIG. 8 along the line 1010;

FIGS. 11-12 are plan views similar to FIGS. 7-8 of still further modifications;

FIG. 13 is a cross-sectional view of a still further form of the apparatus shown in FIG. 6;

FIG. 14 is a cross-sectional view taken through FIG. 13 along the line 1414;

FIGS. 15-16 are schematic views of methods of operations of the apparatus shown in FIGS. 13-14.

DETAILED DESCRIPTION OF THE INVENTION As most clearly shown in FIG. 4, the apparatus includes a vertical or substantially vertical boom 10 of any desired length. At the bottom of boom 10 is mounted a motor section 12 and a vertically fed impellerless blast unit 14 including a blast wheel 16 having radially mounted vanes 18 thereon. The abrasive particles are fed to blast unit 14 through one or more feed pipes 20 which terminate at the top of coarcuate chambers or passageways 24. As shown in FIG. 6 a deflector 22 inside passageways 24 initially spreads the flow of abrasives. The abrasive particles are then fed in a confined manner through passages 26 around motor 28 until they reach plate members 30. Various arrangements for the plate members 36 are shown in FIGS. 7-8 and 11-12. The plate members 30 includes apertures to permit the abrasive particles to be fed in a controlled manner such as a full 360 or a fixed portion thereof to an impellerless blast unit 14. The total area of the various holes for distributing the abrasive is slightly more than the orifice area feeding abrasive to the blast unit 14. Advantageously the abrasive is confined or isolated from the motor 28 and bearing section 32 by casing 34. The whole unit is protected by shrouds 36, 38.

As shown in FIG. 6, motor 28 is cooled by forcing air down tube 40. The air passes through and around the motor windings and reverses direction at section 42 whereupon it then flows up and out through outlet 44. The air blown in is filtered to assure the circulation of clean air.

Advantageously the unit is made in as small a diameter motor can develop through the alternator 46, 118 cycles output to the slave motor. This makes it possible for example to insert a standard 30 HP motor frame mto the boom which develops 50 HP, 3,440 rpm. at the blast unit 14.

In a second arrangement a speed of, for example, approximately 3,500 rpm. can be used by incorporating a two-pole 3,600 rpm. motor for motor 28. By using special high temperature insulation and sufiicient cooling air, the motor size may thereby be kept at a minimum.

FIGS. 7-12. show various advantageous arrangements for plates 30. One arrangement is shown in FIGS. 7 and 9. As indicated therein at least two plates 31, 33 are provided with alignable apertures 35, 37. When the apertures 35, 37 are axially aligned, maximum flow of abrasives is permitted between plates 31, 33. In this arrangement one of the plates such as plate 31 is adjustable so that it can rotationally slide with respect to plate 33. For example, plate 31 may be connected to guide member 29 which is limited in its sliding movement by slot arrangement 39. As apertures 35 and 37 are moved from their axial alignment by movement of one of the plates, the degree of flow of abrasive is decreased.

FIGS. 8 and 10 show an arrangement of plates 30 wherein the plates 41, 43 are fixedly mounted to provide a full 360' feed of abrasive to blast unit 14. FIGS. 11- 12 show further arrangements wherein blocking segments 45 are arranged over the apertured plates to prevent flow of abrasive therethrough. As shown in FIG. 11 where one of the 90 segments is removed the abrasive is permitted to flow through with a resultant 90 blast pattern. FIG. 12 shows an arrangement wherein tWo segments 45 are removed to permit a 180 blast pattern. In this arrangement, however, the removed segments 45 are replaced by apertured segments 47 and can be adjusted in the manner described in FIGS. 7 and 9 to control the amount of abrasive flowing through the plates.

As shown in FIGS. 1-3, the boom 10 is mounted in such a manner as to be tridirectional in movement so that the blast wheel can easily be inserted into otherwise inaccessible locations such as railroad cars 49. This multidirectional movement is accomplished by forming feed tubes 20 in a telescopic manner. A vertical movement up and down is achieved by guide means such as rails 51 (FIG. 3) and collars 53. A sideways or to and fro movement is achieved by rollers 55 (FIG. 1) on rails 57 while a back and forth movement is achieved by rollers 59 (FIGS. 1-2) on rails 61. FIG. 2 illustrates various positions of the blast wheel as indicated by the reference numeral 63.

With the aforedescribed arrangement it is, therefore, possible to insert the boom mounted blast wheel into any interior shape either vertically or at any angle that will feed abrasive by gravity or by pneumatically feeding the abrasive to the blast unit. Additionally the inclusion of a high frequency alternator, for example, facilitates a minimum size motor thus resulting in a unit that will fit into a minimum size hole. Furthermore the resultant blast pattern would have a full unobstructed 360 coverage where desired. Moreover the boom mounted blast wheel does not require long line shafting because the motor 28 is mounted in the boom 10 adjacent to the blast unit 14 thus eliminating the bearing and support problems that are associated with long lengths of shafting.

FIGS. 13-16 show another aspect of this invention which relates to remotely controlling or programming its operation. This arrangement is used in conjunction with the apparatus shown in FIGS. 1-12 with modifications being made to the confined feed means. As indicated in FIG. 13 abrasive particles are fed through tube 20 into an upper chamber 65 which acts as a source of supply for the abrasive particles. A lower chamber 67 is divided into a number of individual noncommunicating coarcuate segments 69 which ultimately lead past motor 28 to blast unit 14 in the manner described with respect to FIG. 6. Chambers 65 and 67 are separated by a power driven rotating plate 71 having one or more orifices 73. The position of the hole or holes 73 is indicated by a switch 75 which is in the path of motion of tripper 77 mounted on plate 71. Switch 75 actuates a counter 80 at the operators panel.

The total area of the holes 73 are slightly more than the area of the abrasive gate 79 in spout 21. Advantageously if the abrasive should back up into upper chamber 65 a probe indicator 81 will shut the abrasive gate 79 until the abrasive level falls. In an alternative arrangement orifices 73 serve as metering feed holes and chamber 65 is made large enough to have high and low level indicators 83, 85 (shown in phantom in FIG. 13). When the abrasive reaches the high level indicator 83, the abrasive gate 79 closes and remains closed until the abrasive reaches the low level of indicator 85. This, thus, insures a head of abrasive over the holes 73 at all times while still preventing the abrasive from backing up into the telescoping feed tubes 20.

The rotation of plate 71 can be remotely controlled and can be programmed by conventional methods of rotational control for electric, air or hydraulic drives.

FIG. 15 shows one use of the remote programmed feed pattern. In this arrangement the part being cleaned has an off center entrance opening. Without blast pattern control area A would receive more blast than area B. However, with the arrangement shown in FIGS. 13-14, plate 71 can be programmed to rotate quickly over area A and more slowly over area B to provide a more uniform blast treatment.

FIG. 16 shows the utilization of this invention for cleaning both the inner and outer surfaces of two cylindrically shaped workpieces with a single boom mounted blast wheel. With this arrangement by having parts 87, 89 rotate the inner surfaces of each part can be cleaned by inserting the blast wheel therein and the outer surfaces can be cleaned when the blast wheel is between the parts 87, 89. The sequence of operation of the blast wheel is indicated by positions 91, 93, 95, respectively.

Obviously many modifications and variations of this invention are possible in light of the above descriptions. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than specifically described.

What is claimed is:

1. An abrasive blasting apparatus comprising an abrasive blast wheel having a plurality of radial vanes thereon, a motor disposed adjacent to and above said wheel, a relatively short shaft connecting said motor to said wheel whereby said motor may rotate said wheel, substantially vertical confined abrasive feed means leading from above said motor to said wheel, said confined feed means including a plurality of coarcuate passageways around said motor, and deflector members being in said passageways to spread the flow of abrasive therethrough.

2. An abrasive blasting apparatus comprising an abrasive blast wheel having a plurality of radial vanes thereon, a motor disposed adjacent to and above said wheel, a relatively short shaft connecting said motor to said wheel whereby said motor may rotate said wheel, substantially vertical confined abrasive feed means leading from above said motor to said wheel, said confined feed means including a plurality of coarcuate passageways around said motor, at least two juxtaposed apertured plates at the bottom of said passageways with the apertures in said plates being alignable to permit flow therethrough, means for moving at least one of said plates to control the degree of fiow therethrough, and said blast wheel being impellerless.

3. An abrasive blasting apparatus comprising an abrasive blast wheel having a plurality of radial vanes thereon, a motor disposed adjacent to and above said wheel, a relatively short shaft connecting said motor to said wheel whereby said motor may rotate said wheel, substantially vertical confined abrasive feed means leading from above said motor to said wheel, said confined feed means including a plurality of coarcuate passageways around said motor, apertured plate means at the bottom of said passageways for permitting 360 flow of abrasive therethrough, and said blast wheel being impellerless.

4. An abrasive blasting apparatus comprising an abrasive blast wheel having a plurality of radial vanes thereon, a motor disposed adjacent to and above said wheel, a relatively short shaft connecting said motor to said wheel whereby said motor may rotate said wheel, substantially vertical confined abrasive feed means leading from above said motor to said wheel, said confined feed means including a plurality of coarcuate passageways around said motor, at least two apertured plates at the bottom of said passageways with the apertures in said plates being alignable to permit flow of abrasive therethrough, one of said plates being removable to facilitate ready replacement by a similar plate having different aperture characteristics, a segment of said removable plate being blocked off whereby a controlled amount of less than 360 flow of abrasive is permitted therethrough, and said blast wheel being impellerless.

5. An abrasive blasting apparatus comprising an abrasive blast wheel having a plurality of radial vanes thereon, a motor disposed adjacent to and above said wheel, a relatively short shaft connecting said motor to said wheel whereby said motor may rotate said wheel, substantially vertical confined abrasive feed means leading from above said motor to said wheel, said confined feed means including telescopic tubes, and tridirectional guide means for moving said blast wheel up-and-down, back-and-forth, and to-and-fro.

6. An abrasive blasting apparatus comprising an abrasive blast wheel having a plurality of radial vanes thereon, a motor disposed adjacent to and above said wheel, a relatively short shaft connecting said motor to said wheel whereby said motor may rotate said wheel, substantially vertical confined abrasive feed means leading from above said motor to said wheel, a casing being around said motor separating said confined feed means from said motor, and air tubes in said casing for cooling said motor.

7. An apparatus as set forth in claim 6 wherein a high frequency alternator is connected to said motor.

8. An apparatus as set forth in claim 6 wherein said motor is of the two-pole type.

9. An abrasive blasting apparatus comprising an abrasive blast wheel having a plurality of radial vanes thereon, a motor disposed adjacent to and above said wheel, a relatively short shaft connecting said motor to said wheel whereby said motor may rotate said wheel, substantially vertical confined abrasive feed means leading from above said motor to said wheel, said confined feed means including an upper chamber, a feed tube leading to said upper chamber, a lower chamber, a power driven rotatable plate separating said chambers, said lower chamber being divided into a plurality of non-communicating segments, and at least one orifice in said plate for selectively permitting communication of said upper chamber with said segments of said lower chamber.

10. An apparatus as set forth in claim 9 including means for programming the rotation of said plate, orifice indicating means, said orifice indicating means including a tripper on said plate, a switch disposed in the path of motion of said tripper, and a counter actuatable by said switch.

11. An apparatus as set forth in claim 9 including probe indication means for indicating a predetermined level of abrasive in said upper chamber.

12. An apparatus as set forth in claim 9 including high and low abrasive level means in said upper chamber.

References Cited UNITED STATES PATENTS 1,876,688 9/1932 Kasser. 2,188,716 1/1940 Jacobovics 51-9 2,263,321 11/1941 Unger 519 2,507,166 5/ 1950 Lehman 51-9 2,900,765 8/ 1959 Blackburn 519 3,052,066 9/1962 Foster 51-9 LESTER M. SWINGLE, Primary Examiner

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