Jan. 17, 1950 w. H. MEAD ETAL 2,494,773 SURFACE TREATING APPARATUS Filed Nov. 13, 1948 2 Sheets-Sheet ,1 2/ 4o) 4 M 42 A; \w ‘ Q> J2 m" 5/ 33 30 .36‘ 3‘629 (.50 3/ 36 60 s § ;< [4 l iii ' \ L32 _ I Q 62 3 4 Iizg.l. . 63 ti 67 L40 68 /'/6 @Mh ATTORNEY ‘ Jan. 17, 1950 w. H. MEAD EI‘AL 2,494,773 SURFACE ‘ TREATING ‘ APPARATUS Filed Nov. 13, 1948 z'sheets-sheat 2 51 énpes -o ASUIPRLY 1/4 INVENTORS WILL/L4H H. MEAD ANDREW BUGHA/V QMZZw A 7' TORNEY' Patented Jan. 17, 1950 2,494,773 UNITED STATES PATENT OFFICE ‘ 2,494,773 SURFACE TREATING APPARATUS ‘William H. Mead, Oakland, and Andrew C. Buchau, San Francisco, Calif., assigno/rs, by mesne assignments, to said Mead Application November 13, 1948, Serial No. 59,924 5 Claims. (0]. 51-8) 1 2 1 This invention relates ‘to surface-treating ap paratus. In particular it relates to improvements in the operating head of an abrader in which the abrasive material is impelled against a working area by a strong pressure blast and is then re moved from the working area along with the abraded particles by an even stronger suction current, for collection in a receptacle. This invention is particularly well suited to solve the problem of cleaning machinery having uneven or relatively intricate surfaces, such as tire molds and the like. Ordinary abrasive clean ing devices widely scatter the grit and abraded A further object of this invention is to provide an operating head which can be adjusted to vary the area and intensity of abrasive impingement, the adjustmentJ also compensating for wear of parts and for different types of surface-treating materials which may be employed. Other objects and advantages of this inven tion will appear in the course of the following description given in accordance with U. S. Re vised Statutes Sec. 4888, though‘without intend ing to limit the scope of the invention otherwise than as claimed. In the drawings: Fig. 1 is a view in elevation and in section of cleaned. This is not only a hazard, but con 15 an operating head which embodies the prin ciples of this invention; for purposes of clarity siderable time must be spent in cleaning up the the bristles in the rear are omitted, although they debris once the abrasive operation is complete. encircle the head as shown in Fig. 2; An alternative abrading method is to place the Fig. 2 is a reduced bottom plan view, looking piece being cleaned within a blast cabinet, but this technique is obviously of limited application 20 up into the open mouth of the head shown in Fig. l; and ‘ and is somewhat impractical at best. Fig. 3 is a view in elevation, somewhat sche The problem has been how to provide a mobile matic in nature, showing a surface—treating ap abrader which could be brought to the machinery paratus of the type with which the operating head or other object to be cleaned and there clean it in place, but with the simultaneous collection of 25 of Fig. 1 may be used. A brief description‘ of the surface-treating ap-' all the abrasive particles and debris. This prob paratus illustrated in Fig. 3 will be helpful in un lem was solved in a general way by the appara derstanding the principles of they improved oper tus described in copending applications, Serial No. ating head which is generally shown at It there 608,386, filed August 2, 1945 which matured as Patent Number 2,455,514 on December 7, 1948, 30 in. An air compressor ll furnishes a stream of ‘ highly compressed air to the duct It. In a man Serial No. 768,198, ?led August 12, 1947 now ner fully described in the aforesaid application abandoned, and Serial No. 778,378, filed October Serial No. 608,386, which matured as Patent No. 7, 1947. However, the operating head (some 2,455,514 on December 7, 1948, the abrasive is fed times described as a “gun”) of the unit described in said applications, is not particularly well adapt 35 into this air-stream from a hopper 13 through a valve 14, a conduit I5 then carrying this abra ed for use with uneven or non-planar surfaces sive-?lled air-stream to the operating head I‘. such as those present on tire molds, for example. where the abrasive particles impinge on the sur ‘ Further, in the unit described in said applica face "5 to be cleaned. A powerful suction pump tions, the mounting of the blast and suction lines leading to the operating head is entirely sepa 40 2|] is also connected to the operating head l8 by a series of conduits through which the spent rate, and for that reason manipulation of the abrasive and any waste particles dislodged there head is made relatively cumbersome; it would be by are drawn back into the unit and are prevented more convenient if a single connection could be used in the vicinity of the head. from passing outwardly of the head In into the It is therefore an object of this invention to atmosphere. Speci?cally, the waste and spent provide an improved operating head for use with abrasive are carried away from the head through particles in the vicinity of the object being ‘ an abrader of the type which simultaneously a conduit 2| to a reclaimer 22 (described in the blast-impels and suction-removes the abrasive co-pending application, Serial No. 778,378) where with impinging air currents drawn in through any re-usable abrasive material is separated from the air pervious skirt. 50 the waste and passed into an upper hopper H from which it is periodicallydischarged into the Another object of this invention is to provide an operating head of the foregoing variety which main feed hopper l3. The waste is sucked out from the reclaimer 22 through a conduit 241 into a can be used in treating uneven, curved, or irregu dust collecting bin 25. lar surfaces, particularly those having small crev Generally, this present invention comprises ices, as the interior of tire molds. 2,494,778 operating head l0 which serves to direct against concentrically arranged inside the brush 83 a surface IE to be cleaned the abrasive or other treating material supplied by the unit described, and also secured to the ?ange 32 is a ?exible ba?le 65, preferably made from natural or syn and which thereafter facilitates the withdrawal of the abrasive and waste particles from the sur face l6 and back into the unit before they can ing, which may beseparate rings secured to escape to the surrounding areas and go into the - atmosphere. This operating head comprises means to direct a blast of abrasive against a surface and suction means to remove the spent abrasive and the waste matter from the surface. A brush en circles the mouth of the head to provide an air thetic rubber. The ba?le 35 preferably comprises a series of stepped rings, as shown in the draw gether or may be molded integrally as steps. Its full thickness (or the total thickness of all the rings) extends a short distance below the open end 32; then it is radially o?’set successively at 66 and 61. The thin lowermost portion 58 of the baiile 65 is shaped to provide air passage inlets, such as the notches 10. In operation, the abrasive is carried from the into the suction current, which is stronger than 15 hose l5 by the air blast into the cap 40. From there it passes through the nozzle 50, which im the blast current. The brush also traps abrasive pinges the abrasive against the surface Hi. The and waste inside the head and serves to prevent suction force being exerted is more powerful than it from spilling outside, holding it until it can the blasting force, so that air passes in through be removed by the suction current. Concen trically arranged inside the brush is an imper 20 the brush 63 and the passages or notches ‘Ill, gathers up’the waste and the spent abrasive and meable ?exible spacer ring having air-passage carries it out around the nozzle 50 into the bore notches cut around its lower end. As will be permeable maze which permits outside air to pass seen, this ?exible ring serves at once to space 34 from where it is carried into the suction hose 2|. the nozzle ,housing from the surface being cleaned, protect the brush, and limit the inward 25 The impermeable baiiie 65 above the notches prevents the inward passage of air, and con?nes passage of air to a thin, powerful stream. the air to the concentrated current passing The head Ill, shown in the drawings, is a pre through the notches ‘I0. Moreover, the brush 63 ferred form of the invention, and it will now be is protected from the wearing action of the abra described in detail. Its metal housing 30 has a straight-through vertical bore 3| open at both 30 sive by the ba?ie 65. Since the baille 65 is made of flexible material, the head readily adapts itself ends 32 and 33. An inclined side bore 34 com to changes and irregularities in surfaces. municates with the vertical bore 3| intermediate What is claimed is: these ends 32 and 33 and at its own outer end 1. In an operating head for a blast-impelling, 35 is detachably secured to the suction conduit 2|. Both bores 3| and 34 are lined with a layer 35 suction-removing, surface-treating apparatus, said head including a hollow housing open at 36 of rubber, which is bonded, as by vulcaniza tion, to the housing 30. The lower end 32 of the housing 30 faces the its lower end where it faces the work surface, the bore of said housing also being in communi cation with a suction line and having means work surface I6 being cleaned. A hollow cap 40 slidesinto the upper end 33 of the housing 40 therein connected with a blast line and for di recting said blast out through said lower end, the and is secured there by set screws 4|. A fitting combination therewith of a circular brush se 42 is threaded into the cap 40 through the open cured around the lower end of said housing to ing 43 adjacent its upper end. The other end of provide a maze-like, air-permeable, impeding the ?tting 42 is detachably connected with the blast hose l5. To permit different connections 45 means and an inner impermeable member se cured around said housing between said housing of the ?tting 42 into the cap 40, additional open and said brush, said member having air pas ings 44 may be provided, with plugs 45 closing sages through its lower periphery. them when they are not in use. 2. The head claimed in claim 1 in which said A nozzle 50, preferably made from a very hard alloy, is threaded into the lower, interior end of 50 impermeable member is made from a resilient material. the cap 40, snugly abutting a washer 5| so as 3. The head claimed in claim 2 in which said to provide a tight ?t. The nozzle 50 extends impermeable member is thicker at its upper end inside the bore 3| but stops short of the hous than at its lower end, whereby it is more ?exi ing's open end 32. At its upper end 52 the nozzle ‘ is funneled in toward a narrower neck portion 55 ble at its lower end. 4. The head claimed in claim 1 in which the 53. Below the neck 53 the nozzle mouth 54 is bore of said housing is protected by an inner lin ?ared outwardly so as to spread out the current of air and abrasive passing therethrough. Slidably mounted around the lower end of the ing of rubbery material bonded to said housing. 5. The head claimed in claim 1 in which the housing 30 is a collar 60, having a set screw 6| 50 brush and the impermeable member are secured to a collar which is slidable around said housing to fix it in any desired position with respect to for adjustment with respect thereto. the housing, as in co-pending application, Serial No. 28,858, ?led May 24, 1948 which matured as - Patent No. 2,483,176 on September 27, 1949. The coliar’s lower end is ?anged at 62, and secured 05 around the outer circumference of the ?ange's bottom surface is a circular brush 63. The brush 63 may be made of pig or Nylon bristles or other suitable materials. WILLIAM H. LIEAD. ANDREW C. BUCHAN. No references cited.