FR2530976A1 - - Google Patents

Abstract

THE INVENTION RELATES TO A TRIM ELEMENT IN THE FORM OF A PLATE FOR COVERING A PROTECTIVE CASING FOR A PROJECTION WHEEL. IT INCLUDES A UPPER END PLATE 52 WHICH HAS AN OFFSET EDGE 170, WHICH COOPERATES WITH AN EDGE 172 OF ANOTHER LOWER END PLATE 54, SO AS TO DEFINE A LABYRINTH-TYPE JOINT BETWEEN THESE PLATES. FLANGE 170 IS L-SHAPED AND CONTAINS SURFACE 174 LOOKING DOWN AND SURFACE 176 LOOKING IN. THE PARTICLES OF MATERIAL BREAK THE JUNCTION BETWEEN PLATES 52 AND 54. APPLICATION TO APPLIANCES FOR TREATMENT OF SURFACES BY SPRAYING.

Description

The invention relates to a packing assembly for coating the

  internal surfaces of the walls of a protective casing of a projection wheel of the type used to project material particles using centrifugal force, the particles being projected at the ends of the blades of a wheel rotating on an object or a surface to clean, erode, hammer

or otherwise treat.

  U.S. Patent Nos. 3,319,383 and 3,160,990 disclose a projection apparatus of US Pat.

  particles of the type comprising a wheel which rotates in the in-

  the interior of a protective casing to force a particle flow through an opening formed in the protective casing, so that these particles strike against the surfaces of objects or parts to be cleaned, eroded, hammered or otherwise treated Each protective casing has a front wall, a rear wall, two end walls and an upper closure wall. A packing assembly is provided to coat the front, rear, end and top walls. The wear packing assemblies described in aforementioned patents comprise in total twenty-three pieces Some or all of these parts are made of cast iron

  very brittle, of the type described in the US Pat.

United States of America No. 2,355,726.

  Although cast iron castings are highly resistant to abrasion, they are very prone to breakage, especially in the corner areas and along the edges, where the ends of the packing pieces have relatively thin sections. The very hard material which constitutes these pieces of packing has an optimal thickness to have

  the type of behavior s Quhaité This optimum thickness

  male is relatively weak; however, the material itself is difficult to cast into section pieces

  relatively thin or complex or rounded shapes.

  In addition, the hardness of the material makes machining or grinding of the packing pieces impossible for cost reasons Therefore, the packing pieces are difficult and expensive to manufacture and

  they form relatively fragile structures, capable of

  be easily broken, which must be transported, stored and handled with care. Although the very hard cast iron whose pieces of

  packing are formed usually presents an excellent

  abrasion resistance sometimes, particles of excessively large dimensions sometimes accidentally reach the projection wheel housed inside the packing assembly. Broken fins can be thrown against brittle lining pieces, causing breakage of the lining In other cases, parts being processed may bounce inside the wheel enclosure and cause the lining to break In fact , breakage of the packing plates are very frequent and the downtime associated with the replacement of parts

pose a problem.

  A disadvantage of the packing assemblies described in the above-mentioned patents 3 319 383 and 3 160 990 is the relatively large number of packing elements necessary to form a complete set.

  filling, with the difficulties and the resulting deadlines

  In addition, the work of handling the large number of fastening bolts used to hold such a large number of plates in position increases undesirably.

the downtime.

  Although U.S. Patent No. 3,191,346 describes a packing assembly before a relatively small number of elements, this patent, as well as the patents mentioned above, does not deal with certain problems. One of these In some markets, it is desired to have a liner assembly having a smaller dimension and using a less expensive technique to seal a wheel shaft. A desirable lining assembly has the lowest possible number of elements while simultaneously achieving an inexpensive sealing device for the shaft, comprising a seal

suitable abrasive.

  The invention aims at the aforementioned drawbacks as well as other disadvantages affecting the prior art packing assemblies and its purpose is to eliminate these disadvantages by means of an improved packing assembly which (1) uses a low number of pieces to completely cover the protective casing of a particle projection apparatus, (2) simplifies the replacement of broken and worn packing pieces and thus minimizes downtime associated with part replacement, (3) form abrasive-proof labyrinth seals, which are very effective between the adjacent lining pieces and a wheel shaft, (4) enables the lining parts to be associated with one another;

  relatively thin and brittle to pieces of

  wise relatively thick and ductile, so that the cast iron

  brittle whose packing parts are usually

  not be used other than more ductile molten steel to form the various parts of the packing assembly, and (5) provides a seal adjacent to the periphery of the packing assembly and the -carter of protection so that it is no longer necessary

  to use a reported sealing plate.

  An important feature of the invention

  lies in the use of packing pieces which

  T-ituent overlapping or interlocking assemblies that not only form abrasive-proof labyrinth seals, but also allow one to be selected,

  pieces of packing to be made of cast iron

  brittle, of relatively thin section, or

  relatively ductile molten steel, of relative

  Thanks to this arrangement, a set of garments

  may consist mainly of relatively thin brittle cast iron packing plates, or a blend of thin and thick

  brittle material and ductile material, respectively.

  By allowing a selection of thin and thick plates used simultaneously in a lining assembly, the invention offers for the first time to the user the possibility of independently determining whether some, chosen, cladding plates should take the form of thin structures. and brittle or thick and ductile structures Thus, thin and brittle plates can be used in areas of high impact, where the resistance to abrasion must be maximum, and thick and ductile plates

  can be used in the desired areas.

  The joining system used to form abrasive-impervious labyrinth seals between adjacent lining plates is characterized by the presence of plate edges of maximum thickness, which cover adjacent plate edges or interlock with edges. makes that the edges of the plates

  covering or interlocking have a maximum thickness

  male increases the strength of the plates and minimizes

risk of rupture of the plates.

  The reduction of the number of pieces of lining

  necessary for the formation of a complete set of

  minimizes the number and length of assemblies in assembled packing By minimizing the number and length of assemblies, the risk of abrasive leakage through assemblies is minimized.

  same as the problem of wear due to such leaks.

  The preferred embodiment of the packing assembly according to the invention may be substituted for packing assemblies such as those described in US Pat. Nos. 3,319,383, 3,191,346 and 3. In addition, there will be described hereinafter an embodiment of the invention in which it is not necessary to use an attached sealing plate, and in which also an improved labyrinth seal for abrasives is provided. for the wheel shaft, which allows the use

  a less expensive shaft seal.

  The invention will be described in more detail with reference to the accompanying drawings by way of non-limiting examples and in which: FIG. 1 is a perspective view, partially exploded, of elements of a preferred form

  embodiment of the lining assembly according to the invention.

  tion; FIG. 2 is an exploded perspective view of the elements of this assembly, placed on a flat surface; FIGS. 3 and 4 are enlarged sectional views of the parts of the packing assembly according to the invention, respectively along the lines 3- 3 and 4-4 of Figures 1 and 3, the parts being laid in a

  protective casing of a party projection apparatus

  cles; FIG. 5 is an enlarged partial sectional view of a detail of FIG. 3, showing relatively thin brittle cast iron cladding plates placed inside a protective casing; Figures 6 and 7 are sections along lines 6-6 and 7-7 of Figure 5; Figure 8 is a partial sectional view similar to that of Figure 5, but showing relatively thick ductile steel coating plates laid within a protective housing; FIGS. 9 and 10 are sections along lines 9-9 and 10-10 of FIG. 8; FIG. 11 is a partial sectional view similar to FIGS. 5 and 8, but showing a combination of molten metal packing plates, relatively thick and thin, fixed inside a protective casing; FIGS. 12 and 13 are sections along lines 12-12 and 13-13 of FIG. 11; FIGS. 14 to 17 are sections according to FIGS.

  line A-A in Figure 1, extreme plates of

  characterized in that features of the invention, FIGS. 14 and 15 for comparing upper end plates of relatively thick and thin packing, and FIGS.

  lower end plates of relative packing

  thick and thin; FIGS. 18 and 19 are sections along the line BB of FIG. 1, upper closure packing plates according to the invention, FIG. 18 showing a relatively thick packing plate and FIG. 19 showing an interchangeable packing plate, but relatively thin; FIG. 20 is a section along the line -20 of FIG. 3, FIG. 21 is a thin section similar to that

  of FIG. 4, of a variant of the set of

  according to the invention, mounted in a variant of

  protective casing of utn projection device par-

  ticles; and Figures 22 and 23 are sections following

  lines 22-22 and 23-23 of FIG. 21.

  As shown in FIGS. 1 and 2, the elements of a packing assembly intended to coat a protective casing of a projection wheel are

  indicated overall by reference numeral 10.

  The packing assembly 10 comprises a structure of

  lining 12 of the front wall, a filling structure

  wise 14 of the back wall, packing structures

  16 and 18 of the extreme walls and a structure of

wise 20 of the upper wall.

  The lining structure 12 of the front wall comprises left, right and central lining plates 22, 24 and 26 The lining structure 14 of the rear wall comprises left, right and central lining plates 32, 34 and 36 The plates The central plates 26 and 36 are identical. The left and right plates 22 and 24 are symmetrical with each other, as are the left and right plates 32 and 34. As shown, the left and right plates 32 and 34 comprise projections 38 in the shape of a segment. moldings, although these projections may consist of one or more

  Sieur patches, if desired.

  The extreme wall packing structure 16 comprises upper and lower packing plates 42 and 44. The end wall packing structure 18 comprises upper and lower packing plates 52 and 54. The upper plates 42 and 52 are identical.

  as are the lower plates 44 and 54.

  The lining structure 20 of the upper wall

  A housing 64 is provided in the top wall packing plate 62 to receive the upper edges of the plates 22, 24, 26, 32, 34, 36, 42 and 52. front, back and extreme walls

  to form between them a labyrinth seal.

  The plates 22, 24, 26, 32, 34, 36, 42, 44, 52, 54 and 62 form an eleven-element packing assembly. However, in reality, this set comprises only eight different plate shapes to be

  stored as spare parts.

  A feature of the eleven-piece packing assembly is that it can be substituted for the twenty-three-piece packing assemblies described in the aforementioned patents Nos. 3,319,383 and 3,591,990, and that it can be laid in the protective housings described in these same patents without it being necessary to modify the said existing protective casings. Reference may be made to the particle projection apparatus described in the aforementioned patents, which are examples of typical apparatus and media in 2 and 4 of the accompanying drawings correspond to FIGS. 1 and 2 of the two aforementioned patents, and show how packing elements according to the invention can be substituted for elements

  packing of the type described in these two aforementioned patents.

  Referring briefly to FIGS. 3 and 4, there is shown a box-shaped protective casing of essentially trapezoidal cross-section, indicated generally by numeral 100. The housing 100 comprises a front pardi 102, a rear wall 104,

  inclined end walls 106 and 108 and a top wall

  110 Closure members Threaded members 112 for securing

  The threaded members 114 attach the lining structure 14 to the rear wall 104. Threaded members 116 and 118 secure the lining structures 16 and 18 to the end walls 106. Fastening threaded members 120 secure the packing structure to the top closure wall 110. Several packing members or plates 10 carry embedded nuts 122 which receive the threaded fasteners 112, 114, 116 and 118 as described. in patents

  N o 3,319,383 and N o 3,160,990, so that these

  The sealing insert 124 is disposed in close proximity to the lower peripheral edge of the packing assembly 10 and the casing 100. The plate 124 prevents particles from being deposited in position on the protective casing 100.

  of material to arrive at the crankcase side of the assembly 10 of -

  packing. The packing plates of the assembly 10 have overlapping or interlocking edges, which cooperate to form labyrinth seals, sealed

  abrasives, between adjacent packing plates.

  The design of the elements of the packing assembly avoids the formation of any openings allowing the projected material to pass directly through the

packing assemblies.

  The left and right lining plates 22, 24, 32 and 34 have U-shaped grooves 140 into which opposing edges of the end plates 42, 44, 52 and 54 penetrate to form U-shaped enveloping labyrinth seals. As shown in FIG. 6, the top end packing plate 52 has an edge 150 which enters a

  groove 140 formed along one side of the

  The throat 140 has left and right and base surfaces 142, 144, and 146. The edge 150 extends narrowly along the left surface 142 and abuts against the base surface 146. 52 have inner surfaces 152 and 154 which intersect in substantially perpendicular planes. When the material to be projected is propelled towards the junction of the plates 24 and 52, it must change direction several times substantially at right angles to penetrate the labyrinth seal. Also, as shown in FIG. 7, the packing plate 54 of the former lower end has an edge 160 which penetrates into the groove 140 formed along a longitudinal axis. side of the lining plate 24 of the wall

  The edge 160 extends narrowly along the

  right face 144 and abut against the base surface 146.

  When the material to be projected is propelled towards the junction of the plates 24 and 54, it must change several times of direction substantially at right angles to be able to penetrate into the enveloping labyrinth seal, of shape

  in U, constituted by this assembly.

  The various packing plates which each form structures 12, 14, 16 and 18, have overlapping edges, which constitute labyrinth seals between the different adjacent plates. As an example, as shown in FIG. upper end 52 has a remote edge 170 which cooperates with an edge 172 of the lower end plate 54 to form a right-angle labyrinth seal. The edge 170 is L-shaped and has a surface 174 facing downwards and a surface 176 turned inward The trim plate 54 from the end

  bottom has a surface 178 facing the interior

  which is adjacent to the inner surface 154 of the packing plate 52 of the upper end, and its upper end 180 abuts against the surface 174 when the material to be sprayed is propelled towards the junction of the plates 52 and 54 , it must change direction approximately at right angles to enter the formed L-shaped labyrinth seal

between plates 52 and 54.

  Similar L-shaped labyrinth seals are formed between other plates constituting the structures 12, 14, 16 and 18. For example, as shown in FIG. 20, the packing plates 22 and 26 of the The front wall has overlapping edges 190 and 192 which form a labyrinth seal between them. No direct opening allows the projected material to traverse the lining assembly in a straight line. The packing plates of the assembly 10 and the assemblies formed together when the elements are assembled, are configured in such a way that some of the elements comprising these plates can be selected.

  selectively made of a brittle metal, relatively

  thin, or of a relatively thick ductile metal.

  By way of example, FIG. 5 illustrates the use of relatively thin upper and lower end plates 52 and 54 covering the end wall 108 of the guard, while FIG. 8 illustrates the use of top and bottom plates. a and 54 has relatively thick, covering the end wall 108 of the guard, and that Figure 1 i illustrates the use of a combination of thick and thin plates 52a and 54 covering the end wall 108 of the housing

protection.

  Thin packing plates are conventionally used in projection wheel guards, since the brittle alloy, extremely hard,

253 '0976

  it of which these plates are made (this alloy being described in the aforementioned patent No. 2,355,726), has an optimal behavior at a relatively low thickness When these plates are made to a thickness greater than the optimum value, their abrasion resistance decreases significantly When an alloy more

  ductile must be used, for example steel with manganese

  of Hadfield, such material can not be properly cast into thin-section

  therefore thicker packing plates.

  According to a feature of the invention

  the overall thickness of the upper packing plates 52 and 52a, this thickness being indicated by the dimension "XI" in FIGS. 14 and 15, is kept constant irrespective of the thin or thick plates, 52 or 52 a Similarly, the overall thickness of the lower packing plates 54 and 54 a, indicated by the dimension "Y" in Figures 16 and 17, is minent constant, as thin plates

  or thick 54 or 54 a be used Similarly, the thick

  The overall size of the upper packing plates 62 and 62a, indicated by the dimension "Z" in FIGS. 18 and 19, is kept constant, whether thin or thick plates 62 or 62a are used. Keeping the thicknesses, such as the overall dimensions X, Y and Z, it is possible to use thin and thick boards interchangeably to coat the end walls and upper 106, 108

and 110 of the housing 100 of protection.

  Although the plates of the set of

  Preferably, these elements may be made of other materials, such as forged metal, with welds being used to form parts of the molded metal, as is obvious to those skilled in the art. making up the labyrinth seals

described and others.

  FIGS. 21 to 23 show a variant of the packing assembly 10 and the protective housing 100 previously described, these embodiments

  are respectively indicated by the references

  In contrast to the packing assembly 10 and the protective casing 100, the packing assembly 210 and the guard housing 300 are less expensive to manufacture, smaller in size and have a protective device. less expensive tree sealing. The lining assembly 210 comprises a lining structure 212 of the front wall, a lining structure 214 of the rear wall, lining structures 216 and 218 of the end walls, and a lining structure 220 of the top wall. front wall packing liner 212 comprises left, right and central lining plates 222, 224 and 226 The rear wall lining structure 214 comprises left, right and central lining plates 232, 234 and 236 The left plates and straight lines 222 and 224 are symmetrical to each other,

  same as the left and right plates 232 and 234.

  As shown, the left and right plates 232 and 234 have protrusions 238 in the form of ring segments, integrally molded.

  may consist of one or more pieces of

if desired -

  The central plate 236 has an opening 239 in which the shaft (not shown) of the wheel passes. Unlike the embodiment shown in FIGS. 1 to 20, the opening 239 is not formed.

  In addition, annular projections

  Horizontal lugs 240 and 241 extend laterally from the front and rear faces of the plate 236. The projections 240 and 241 are substantially in the form of annular flanges which form labyrinth seals with the wheel shaft. A feature of the embodiment shown in Figures 1 to 20 is that the side trim plates 22, 24 and 26 can be removed without disassembly of the wheel rim

  nor other elements of the assembly comprising the wheel.

  In Figures 21 to 23, this feature does not exist, but a better labyrinth seal for abrasive

is made with the wheel shaft.

  The end wall packing structure 216 comprises upper and lower packing plates 242 and 244, and the end wall packing structure 218 comprises upper and lower packing plates 252 and 254. The upper plates 242 and 252 are identical, same as are the lower plates 244 and 254 The packing structure 220

  of the upper wall consists of a single plate of

  264 of the upper wall A housing 264 is formed in the lining plate 262 of the upper wall to receive the upper edges of the plates 222, 224, 226, 232, 234, 236, 242 and 252 of the front walls, back The labyrinth seals analogous to those shown in FIGS. 1 to 20 are used in the embodiment of FIGS. 21 to 23. The joint thus formed and used allows the installation of the labyrinth seals to be formed. thick or thin plates, as

  desired, and as described above.

  The housing 300 of protection, shaped box, has a substantially trapezoidal section It comprises a front wall 302, a rear wall 304,

  inclined end walls 306 and 308, and a top wall

  The latter comprises two parallel plates 312 and 314 which extend across the upper opening of the housing 300. The plate 312 has openings which can be aligned with openings in tabs 316 and 318 protruding laterally from the walls. 302 and 304, so that each pair of aligned apertures can receive a fastener such as a nut and a bolt 320, so that the top closure wall 310 can be fixedly bolted to the guard 300 This closure mode eliminates the knobs, profiles and eyebolts shown in the upper part of FIGS. 3 and 4, is of low weight and is relatively inexpensive to manufacture As in the embodiment of FIGS. 1 to 20, threaded members 322 are used to secure the plates 222, 224, 226, 232, 234, 236, 242, 244, 252, 254 and 262 on the parts

corresponding to the housing 300.

  The guard 300 of protection has an opening

  323 of discharge by which its wheel propels

  particles of matter under the effect of centrifugal force.

  The bottom trim plates 244 and 254 of the end walls have tabs 324 and 326 protruding laterally. These tabs 324 and 326 are adjacent to wall members 328 and 330 to which the casing 300

  is fixed by flanges 332 and 334 extending towards the former

  The legs 324 St 32 Ciphers the particles of projectiles from the meeting zone of the elements 328, 320, wings 332 and 334

  and faces of the planks 244 and 254 facing the housing.

  In the embodiment shown in FIGS. 21 to 23, the plates 222, 224, 226, 232, 234, 236, 242, 244, 252, 254 and 262 form an eleven-piece packing assembly 210 but, in reality, this assembly comprises only nine different plate configurations to be stored as spare parts. In FIGS. 22 and 23, the central plates 226 and 236 do not have identical configurations, as is the case

  central plates 226 and 236 of FIG.

  A feature of the set of garments

  nissage is that it can be substituted for the sets of lining with twenty-three pieces described in the aforementioned patents N 3 319 383 and NO 3 160 990, and that it can be put in place in the protective casings described in these two aforementioned patents , without the need

  modify the existing protective casings

  210 appears to lining and its protective casing 300 are smaller than the assembly 10 and the casing 100; the housing 300 and the assembly 210 are intended mainly for applications in which parts of dimensions

smaller ones are used.

  Although reference has previously been made to an orientation of the protective casings 100 and 300 such that their opening is turned downwards, a particle projection apparatus of the type described can be oriented so as to project particles in any direction. Therefore, it is obvious that terms such as "upper", "lower", "forward", "backward", "upward", "downward", and the like as used herein , are intended simply to facilitate the understanding of the relative orientations of various elements and that they are not given

as a limitation.

  It goes without saying that many modifications can be made to the packing assembly described

  and shown without departing from the scope of the invention.

Claims (7)

  1 Plate-shaped packing element   intended to cover part of a housing (100) of   tection inside which is mounted a pro-   jection which can rotate to propel particles of material under the effect of centrifugal force, through a discharge opening (323), the packing member   being characterized in that it presents a first sur-   face (54) exposed to propellant particles of matter   by the rotating projection wheel, a second sur-   face (52), disposed on the other side of the guard element   relative to the first surface and comprising both means (122) for securing the packing member to the housing and a substantially flat body (52), at least one linear portion (170) of an edge of   this body being deported relative to the plane of the latter.   2 packing element according to claim 1, characterized in that it further comprises a tab (324, 326) projecting laterally and located near the discharge opening (323) to prevent particles of material from entering the area of the   second surface and in the protective housing (100).   3 packing assembly according to claim 1, characterized in that it has an opening (239) in which the shaft passes and which has a peripheral edge   continuously defined by the packing element.   4 Packing unit according to the claim   3, characterized in that it further comprises annular flanges (240, 241) surrounding the opening (239) on each side of the lining member, and   projecting laterally outward from this element -   Packing element according to claim 1, characterized in that it is made of an alloy described in the patent of the United States of America No. 2,355,726.   Packing element according to claim 1, characterized in that the substantially flat body has along at least a portion of its periphery 47 a groove (64) which is sufficiently wide to accommodate a portion of an edge a relatively thick or relatively thin plate-shaped member so that a   labyrinth seal, abrasive-proof, be formed.   7 packing element according to claim 6, characterized in that the groove (64) has a U-shaped section. 8 Packing element according to claim 6, characterized in that it is aligned with a portion of a side wall, substantially trapezoidal, the guard (100).   9 packing element according to claim 6, characterized in that it is made of an alloy   described in U.S. Patent No. 2,355,726.   A packing member according to claim 1, comprising a horizontally extending plate-shaped member, characterized in that it comprises a groove (64) along a portion of its peripheries, said groove having a width sufficient to receiving a rim of a plate member, either relatively thick or relatively thin, so as to provide a   seal labyrinth sealed to abrasives.