US3495308A - Apparatus for forming pipe fittings - Google Patents

Description

Feb. l7, 1970 c, sc u z I 3,495,308

APPARATUS FOR .FORMING PIPE FITTINGS Filed March 14, 1966 a Sheets-Sheet 1 INVENTOR. Ila/255m- 6'. 62/104 25 flrrole/ver Feb. 17, 1970 APPARATUS FOR FORMING PIPE FITTINGS I 3 Sheets-Sheet 2 Filed March 14, 1966 FIG.2

' H. c. SCHULZE 3,495,308

| lllll L h I 28 I INVENTOR. Ila-25522" 6. Jaw/4 ZE llrrae/vzr Feb. 17, 1970 H. c. SCHULZE 3,495,308

' APPARATUS FOR FORMING PIPE FITTINFSI Filed Mamh 14, 1966 3 Sheets-Sheet 5 v E'EBEE? C'Hl/LZE FIG. 8

United States Patent C Int. Cl. B28b 21/12 US. CI. 25-30 2 Claims ABSTRACT OF THE DISCLOSURE An apparatus for compacting clay and other materials into shapes, particularly hollow shapes, utilizing multiplepart dies including segments less than one-half the circumference of the shape being formed.

The present invention relates generally to an apparatus for compacting particulate matter and more particularly to an apparatus for pressing relatively dry particulate matter into pipe fitting shapes for later vitrification.

Vitrified clay and analogous materials are widely used in sewage piping systems and the like because of the characteristic resistance of such material to attack by acids and other impurities present in sewage. Sewage pipe fittings are most commonly manufactured by forming by extrusion or the like from clay containing from 13% to 19% moisture a piece of pipe and cutting a hole in the side of such piece of pipe, thereafter forming a second piece of pipe and cutting its shape to fit the hole in the first piece of pipe. These two pieces are then fitted together at the hole and manually molded until the tWo pieces are knit together. At this point the fitting is completely formed, although not adequately knit as it is next to impossible to get a complete knitting at the cut edges of the two pieces of pipe even by extended hand molding. The fitting as formed must then be dried under very carefully controlled conditions until the moisture content has been reduced to considerably below in order that it will not be damaged upon firing at a high temperature. This step of firing at a high temperature is necessary in order to vitrify the clay and make it usable as vitrified clay pipe.

It is deemed desirable to form a pipe fitting as a unitary item from granular clay or the like and particularly it is desired, if possible, to do this with clay having moisture content of 13% and lower, with a moisture content as low as 6% being desirable.

When it is possible to form the unitary item, whether formed of relatively wet clay as normally used or formed of dryer, clay, there is a distinct advantage in eliminating the insecure joint between the two pieces of pipe which normally exists in the presently existing commercial methods of .manufacture. The additional advantage of eliminating the drying step is deemed a great advantage if possible and there have been considerable attempts to achieve this result.

It has been proposed to press dry clay particles into a coherent fitting, however such attempts have proven generally unsatisfactory, probably because even under high pressing pressures, clay particles do not readily undergo flow. This phenomenon is discussed at length in my copending patent application Ser. No. 407,700, filed Oct. 30, 1964 and entitled Method and Apparatus for Compacting Particulate Material.

It has also been proposed to mold under pressures pipe fittings in a two-piece mold utilizing an extrusion process to compress clay about a core. The clay utilized is generally quite moist, in the neighborhood of 13% to 20% moisture, and even though it may be possible to effect considerable flow of the clay, such process results in an additional disadvantage, namely the two-piece mold or opening has a tendency to crack the fitting. Alternatively, the fitting will have a tendency to become snagged in one side or the other of the mold, giving rise to rupture planes. This phenomenon appears to result from the fact that the clay expands slightly when the two-piece mold is opened.

It is a major object of the present invention to provide an apparatus for making a clay fitting from relatively dry particulate clay.

Another object is to provide an apparatus of the foregoing nature utilizing a novel mold that is divided in such a way that there are more than two mold sections whereby the fitting is removed from the mold under conditions which do not lend themselves so readily to the natural rupturing tendency and sticking tendency caused by the expansion of the clay in the mold.

It is a further object of the present invention to provide an apparatus for pressing relatively dry particulate clay or like matter within the space defined by a hollow mold and an inner core in a uniform manner characterized by good compaction throughout.

Another object of the invention is to provide an apparatus of the aforedescribed character in which the compacting ram and the central core move in common so that undesirable wedging and jamming of the particulate matter is substantially eliminated and the *whole clay mass is relatively evenly compacted.

Yet another object of the invention is to provide an apparatus of the aforementioned character wherein the mold includes cylindrical portions characterized by a multi-part construction, each of the parts being separable from the others to permit removal of the molded fitting, and each of the parts defining less than degrees of the fitting circumference to thereby permit swelling and consequent easy removal of the fitting upon separation of the mold parts.

A further object of the invention is the provision of an apparatus of the aforementioned character wherein branch fittings having elongated main and branch sections are formed of particulate matter compacted substantially simultaneously by rams operative through each of the open ends of the mold, thereby providing improved compaction throughout the particulate mass.

Another object of the invention is the provision of an apparatus of the aforementioned character which is adapted to handle various forms of particulate matter other than clay and which is further adapted to adjust compacting pressures according to the character and moisture content of the material being compacted.

Other objects and features of the invention will become apparent from consideration of the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is an elevational view, partly broken away, illustrating a preferred form of dry press pipe fitting apparatus embodying the present invention;

FIG. 2 is an enlarged detatil view of the molding components of the apparatus of FIG. 2, the components being illustrated in elevational cross section in their positions just prior to the compacting operation;

FIG. 3 is a view similar to FIG. 2, but illustrating the positions of the molding components upon completion of a compacting operation;

FIG. 4 is an enlarged detail view of the underside of the side mold sections in their open positions, the actuating cylinders therefor being omitted for brevity;

FIG. 5 is a view similar to FIG. 4, but illustrating th side mold sections in their closed positions;

FIG. 6 is a perspective view of an alternative form of mold embodiment to accomplish the same result as the mold of FIGS. 1-5 and showing a different configuration of pipe fitting;

FIG. 7 is a broken vertical sectional view taken on line 77 of FIG. 6 just prior to the forming operation; and

FIG. 8 is a view similar to FIG. 7 but showing the appearance of the parts after the forming operation has been completed.

Referring now to FIGS. 1-5 of the drawings, there is illustrated a first form of dry press pipe fitting apparatus 10 according to the present invention. The apparatus 10 comprises, generally, a frame 12 for mounting the various components of the apparatus; a hollow mold 14 having a main portion 16 and a branch portion 18; a main core or mandrel 20 operable within the mold main portion 16; a branch core or mandrel 22 operable within the mold branch portion 18; a main die head or mold closure 24 at the lower end of the mold main portion 16 and a similar branch die head or mold closure 26 at the open end of the branch portion 18; a funnel 28 at the top of the mold 14 for filling the mold with particulate matter; and a number of fluid-actuated rams for operating certain of these components.

The frame 12 merely serves as a mounting for the various other components of the present apparatus and may take any suitable form. In the embodiment illustrated, the frame 12 is made of heavy steel sections and includes a pair of spaced-apart uprights 30 and 32 which are connected together by vertically spaced-apart, horizontal beams 34, 36 and 38, and by a horizontal channel or shelf 40. Another steel section at the bottom constitutes the frame base 42, and a pair of A-frame structures 44 are welded to the uprights 30 and 32 to provide stability.

A conventional combination of an electric motor 46 and a hydraulic pump 48 provides fluid under pressure to a manifold 50 which is operated to supply fluid under pressure to various hydraulic rams, as will be seen. The manifold controls are omitted for brevity since such controls are conventional and easily procured when the fluid valving requirements are known, as will become apparent from the description which follows.

The mold 14 is preferably vertically oriented to facilitate gravity 'feed of particulate matter into the mold cavity. The particular mold 14 is adapted to produce a pipe fitting sometimes referred to as a Y branch or Y fitting, and the particulate matter may be any of the well-known clay mixes used in the production of vitrified pipe. Although reference will frequently be made to clay, it will .be understood that the apparatus 10 may also be used with a variety of other particulate matter such as cement mixes, metal particles, earth mixes and the like.

The moisture content of the clay is important to the optimum operation of the apparatus 10, but a precise specification of moisture content is not possible because of the many variables involved, such as the particle size and compacting pressures utilized. However, the proper moisture content is easily established after a few trials. The clay particles may be dry to the touch, so as to not adhere to one another, and should not stick to the apparatus components upon completion of the compacting operation. Too little moisture can be detected by a failure of the compacted part to hold its shape and maintain its structural integrity. As previously indicated, this is also a function of compacting pressures, which, by way og example, may impose in the order of ten or fifteen tons load on eight inch pipe fittings, although these loads vary considerably under diflerent circumstances.

Moisture content with representative clays can successfully be held to 10% and below with any normal type of 1 The particular construction of the mold 14 is important to reduce sticking of the formed part. In the prior art comparable molds are generallymade in two parts, each comprising one-half or degrees of the mold cavity. However, this construction fails to take into account the phenomenon of swelling or expansion of the pipe fitting which occurs when the mold parts are separated. The fitting apparently is not sufiiciently free to expand in a 180 degree mold and sticking occurs between the fitting and the mold. 1 a

To avoid such sticking the mold 14 is constructed in three parts, as best viewed in FIGS. 1, 4 and 5. A fixed section 52 defines the cylindrical, elongated upper portion of the mold main portion 16, but is split at the juncture of the main and branch portions 16 and 18. At this juncture the fixed section 52 extends laterally to form the upper part of the branch-portion 18. The fixed section also extends downwardly to the lower end of the mold 14 to define the outer part of the lower end of the mold main portion 16, that is, the section of the main portion 16 remote from the branch portion 18.

A pair of confronting side sections 54 complementally fit against the fixed section 52 and against each other to complete the main and branch portions 16 and 18. More particularly, each side section 52 constitutes one-half of the adjacent lower section of the main portion 16, interfitting with the fixed section 52 along a V-shaped parting line. Each of the side sections 54 comprise less than 180 degrees of the circumferences of the main and branch fittings so that all of the sections 52 and 54 are less than 180 degrees in extent. The particular arcuate extent of these sections can be varied as desired, but should be kept less than 180 degrees to minimize sticking problems.

The fixed section 52 is secured in stationary position by a collar 56 which is Welded to the upper extremity thereof and bolted or otherwise fixed to the beam 36. As best viewed in FIGS. 4 and 5, the side sections are mounted to piston rods 58 which are operative by conventional double-acting hydraulic cylinders (not shown) for movement of the side sections along a horizontal axis. The hydraulic cylinders are secured to the shelf 40 to confine the side sections to movement along such axis, at right angles to the longitudinal axis of the mold branch portion 18.

The fixed section 52 includes laterally oriented, oppositely projecting flanges or tongues 60 on both the main and branch sections thereof for projection into mating grooves 62 defined by channels secured to the corresponding sections of the side sections 54. This locks the sections together for resistance to internal pressure in the closed positions of the sections,.as best viewed in FIG. 5.

The hydraulic cylinders'for actuating the piston rods 58 are operated by fluid under pressure from the manifold 50, as will be apparent. I

The main mandrel 20 is elongated and cylindrical in configuration and extends through the open upper end of the mold 14 and into the interior thereof to define an annular mainmold cavity 64 withthe cylindrical inner Walls of the mold main portion 161 A pressure ring or annular ram portion 66 approximating the diameter of the mold cavity 64 is fixedly secured to the upper extremity of the mandrel 20 and'is movable downwardly with the mandrel to compact clay in the cavity 64, as will be seen. The ram portion 66 is preferably made of a resilient material such as nylon to prevent damage to the walls of the cavity 64 in the event that hard, abrasive constituents of the clay mixture become wedged between the ram portion 66 and the cavity walls.

The mandrel 20 is movable vertically by a conventional double-acting hydraulic cylinder 68 which is secured to thoe beam 34 and connected by fluid lines to the manifold 5 v The lower end of the mandrel 20 slidably extends through a central opening provided in the main mold closure 24 and through the hollow interior of a cylindrical piston or ram 70 which is connected to the closure 24.

The ram 70 is closed at its lower end and is actuated upwardly and downwardly by a conventional double-acting hydraulic cylinder 72 which is fixed to the frame base 42 and beam 38. Thus, the closure 24 is movable independently of the mandrel 20 while yet slidably accommodating the mandrel 20 during its downward movement.

The lower end of the mold 14 includes a larger diameter bell 74 which longitudinally slidably receives the closure 24, as best viewed in FIG. 2, with the closure being further movable into the bell 74 during a compacting operation, as best viewed in FIG. 3.

The open end of the mold branch portion 18 also includes a larger-diameter bell 76 which, in this instance, longitudinally slidably receives the branch mold closure 26, as best viewed in FIG. 2. The closure 26 is secured to the upper end of a hollow piston or ram 78 which in turn is secured to a conventional double-acting cylinder 80 having two coaxially arranged cylinder or ram sections. The outer section is operative by fluid under pressure from the manifold 50 to move the closure 26 in and out of the bell 76, while the inner section mounts the branch mandrel 22 and is similarly operative to slidably move the mandrel 22 through a central opening in the closure 26 and into and out of the mold branch portion 18. In its most inward position the mandrel 22 is in engagement with the main mandrel 20 and for this reason includes an arcuate or concave end adapted to complementally fit upon the curved periphery of the mandrel 20.

The cylinder 80, mandrel 22, and the closure 26 are all arranged along an inclined axis coincident with the axis of the mold branch portion 18 and are maintained in this position by securement of the cylinder 80 to the frame upright 30.

The frusto-conical funnel 28 is welded at its lower end to the collar 56 adjacent the mold 14 to define a filling area for receiving particulate clay. The clay enters the mold cavity 64 through slots 82 provided in the upper extremity of the mold 14, and a conventional vibrator 84 is attached to the funnel 28 to facilitate passage of the clay into the cavity 64. Another similar vibrator 86 is attached to the stationary section of the branch portion 18 to facilitate passage of clay from the cavity 64' to the annular branch cavity 88 defined by the inner walls of the branch portion 18 and the central branch mandrel 22, as will be seen.

In operation, the main mandrel 20 and main mold closure 24 are raised to the positions illustrated in FIG. 2, it being noted that the lower end of the mandrel is located within the central opening of the closure 24, and the ram portion 66 is located above the filling slots 82.

The mold side sections 54 are moved to their closed position, as illustrated in FIG. 5, the branch mandrel 22 is brought into engagement with the main mandrel 20, and the branch closure 26 is moved into the bell 76, as illustrated in FIG. 2.

The funnel 28 is filled with clay and the vibrators 84 and 86 operated to completely fill the cavities 64 and 88.

The cylinders 68, 72 and 80 are actuated by fluid at a common pressure passing from the manifold 50, causing the closures 24 and 26 to compact the clay, particularly in the bells 74 and 76, and causing the ram portion 66 and main mandrel to move down together to compact the clay in the cavities 64 and 88. It is important to note that by virtue of the movement of the main mandrel 20 with the descending clay, the clay is sheared in opposite directions by the mandrel 20 and the walls of the cavity 64, thereby substantially eliminating any undesired wedging action of the clay between these surfaces. Simultaneous with the motion of mandrel 20* and its ram portion 66, the closures 24 and 26- are caused to advance upwardly so as to fully compact the clay in the bell portions of the fitting.

Pressure is vented from the cylinders to place the molded fitting under no pressure, and the side sections 54 are actuated to their open positions, as illustrated in FIG. 4. The compacted clay expands slightly when the side sections are opened and freely parts externally from the walls of the mold cavities as well as from the adjacent sections of the mandrels 20 and 22.

The branch mandrel 22 is then retracted, followed next by retraction of the branch closure 26. The main mandrel 20 is again actuated downwardly to push the molded fitting downwardly and out of the mold 14. The mold closure 24 is also moved downwardly at this time to support the molded fitting. After the fitting has cleared the mold 14, the clay expands slightly, facilitating upward movement and withdrawal of the main mandrel 20.

Referring now to FIGS. 6, 7 and 8, there is shown an alternate embodiment of the present invention adapted to form a so-called T fitting rather than the Y fitting shown in FIGS. 1 through 5. It should be noted that the embodiment of FIGS. 6, 7 and '8 employs a poweroperated main mandrel 20' and a power-operated branch mandrel 22, as well as power-operated closures 24' and 26' similar to the unprimed parts so designated in FIGS. 1 through 5 and operated by hydraulic cylinders 68 and similar to those described in conjunction with the apparatus of FIGS. 1 through 5. It should be further noted that in the embodiment of FIGS. 6 through 8 the main mandrel 20' is arranged in a horizontal position rather than in the vertical position of ram 20 of FIGS. 1 through 5, while the branch mandrel 20' is arranged to act vertically rather than horizontally in the case of the embodiment of FIGS. 1 through 5. The mold 14' is also generally similar in construction to the aforedescribed mold 14, except that mold 14' defines a T-shaped cavity rather than a Y-shaped cavity.

In the operation of the embodiment of FIGS. 6, 7 and 8, clay or other matter is introduced to the interior of mold 14' by a tube by means of a pressurized stream, by gravity or other conventional feeding arrangement utilized for feeding granular materials.

After the material has been deposited in the mold 14' the main mandrel 20 is moved forward and the two bells 24' and 26' are moved forward to positions indicated in FIG. 3 completing the manufacture of the pipe fitting.

Although it has not been illustrated it has been found that particularly good results are obtained if, in addition to the items shown in the drawings, a vacuum line is connected to the mold with suitable screen to avoid the clay being drawn into the vacuum line, and a vacuum drawn on the clay-filled mold prior to the compaction taking place. By doing this most of the air, which might otherwise be entrapped with the clay materials, is eliminated. Although this step is not completely necessary it is an excellent stepto be taken and has been found to be most desirable in obtaining the maximum quality clay pipe fitting.

It will be observed that in this particular embodiment shown in FIGS. 6, 7 and 8, the mold 14' is in three pieces with respect to the main pipe portion. It will be observed, however, that the mold splits on a half circle with respect to the branch portion. This arrangement has been found satisfactory, since apparently the principle expansion under these circumstances can be allowed to radiate downwardly into and be absorbed by the main portion of the pipe. In experiments with the particular embodiment shown in FIGS. 6, 7 and 8, it has been found that damage due to the expansion of the clay and sticking of the clay is parting from the spirit of the invention or the scope of the following claims.

I claim:

1. Apparatus for compacting particulate matter into a self-supporting mass, which hollow mass has intersecting inner hollow portions comprising:

a mold consisting of more than two parts defining the exterior of the finished self-supporting hollow mass, said parts each opening on sections less than 180 degrees each around the periphery of the molded article;

core means extending through said mold in its longest straight direction;

end closure means cooperating with said core means to provide a retention of material within said' mold;

ram pressing means cooperating with and carried by said core and moving with the same when the same is moved;

core means comprising a first core extensible into the self-supporting mass, said apparatus comprising:

an elongated hollow mold having a main portion and a branch portion and separable into more than two mold parts, each of which defines less than 180 degrees of the periphery of the mold at the intersection of the branch and the main portion;

an elongated first core extensible through an open end of said mold and into the interior thereof to define a cavity, said core including a ram portion;

a second core extensible into said branch portion to define a branch cavity;

mold closure means for closing the end of said mold opposite said open end and including an opening for receiving said core;

mold closure means surrounding the second core at the branch opening, said mold closure means being operable independent of said second core;

8 means for filling said cavities with particulate matter;

first ram means for effecting relative longitudinal movement of said mold and said first core to urge said first core through the opening in the associated one of said closure means and to urge said ram portion against said particulate matter;

second ram means for advancing and retracting said closure means respectively to and from said mold; and

means for separating said mold parts to permit extraction of the molded part.

,References Cited UNITED STATES PATENTS 1,368,268 2/1921 Legnard a"- 18-38 1,941,299 12/1933 Greenidge 25-127 2,253,003 8/1941 Whipple. 2,282,155 5/1942 Bandur.. 2,865,079 12/1958 Marchiole et al. 25-127 XR 2,896,259 7/1959 Harris "a 18-33 2,966,713 1/1961 Billner 25-127 XR 3,131,434 5/1964 Harris 18-33 3,176,350 4/1965 Ryen et al. 18-33 1,634,045 6/1927 Porter. 1,773,447 8/1930 Coult'er. 1,884,528 10/1932 Benner et al. 1,896,939 2/1933 Calkins et a1 18-165 XR 2,033,735 3/1936 Pack. 2,079,393 5/1937 Bengc.

2,556,951 6/1951 Weidner 1816.7

2,630,041 3/1953 Perry et al. 2,681,494 6/1954 Weber 249- 2,815,535 12/1957 Bodine 25-415 XR 2,864,125 12/1958 .Kelley 25-102 XR 2,909,826 11/1959 McElroy 25-102 XR 3,094,758 6/1963 Downie et al. 25-102 XR 3,200,465 8/1965 Lassman 25-27 3,329,753 7/1967 Sourwein 18-165 XR FOREIGN PATENTS 131,059 3/1957 Denmark,

WILLIAM J. STEPHENSON, Primary Examiner US. Cl. X.R.

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