US2537585A - Concrete mixer water injection device - Google Patents

Description

Jan. 9, 1951 G. HILKEMEIER 2,537,585

CONCRETE MIXER WATER INJECTION DEVICE Filed June 25, 1947 2 Sheets-Sheet 1 .L..G. HILKEMEIER INVENTOR.

ATTORNEY Jam 1951 L. e. HILKEMEIER 2,537,585

CONCRETE MIXER WATER INJECTION DEVICE Filed June 25, 1947 2 Sheets-Sheet 2 LOUIS s. HILKEMEIER INVENTOR.

TTORNEY Patented Jan. 9, 1951 CONCRETE MIXER WATER INJECTION DEVICE Louis G. Hilkemeier, Greenfield, Wis., assignor to Chain Belt Company, Milwaukee, Wis., a corporation of Wisconsin Application June 25, 1947, Serial No. 756,842

2 Claims.

This invention relates to means for introducing water into concrete mixers and provides injection apparatus which may be submerged in the concrete making ingredients, and Which will inject the water into the materials in an improved manner. It is also a feature of the device that when an adequate supply of water has been introduced into the batch, and the supply of water is shut off, the concrete is prevented from entering the orifice where it would otherwise tend to set up and interfere with the functioning of the device in the mixing of subsequent batches.

In my Patent No. 2,360.344, issued October 1'7, 1944, entitled Concrete Mixer Water Supply System, there is disclosed an arrangement of water introduction means for such mixers which has proven very satisfactory in promoting rapid mixing. The principal advantages of the arrangement disclosed in that patent reside in the location of the orifice of the water introduction means and the direction in which the water is caused to flow from the orifice, as well as the cooperation between the blades in the mixing drum and the disposition of the water introduction means relative thereto.

The principal drawback, however, of the apparatus disclosed in said patent is the fact that the valve in the water nozzle does not always seat perfectly and prevent concrete from lodging between the valve and its seat. This causes interference with subsequent water introduction.

impossible to flush the drum as soon after dis-' charge as is desirable, and on other occasions the operator neglects to do so.

It has been found that where a rubber gasket is used as a check valve to seal the nozzle orifice,

said gasket being deformable under pressure to permit water passage between it and its seat, fine silt-like material will collect between the seat and the gasket during the period of water introduction. A certain amount of such fine material will not in itself cause trouble, but eventually due to the permanent deformation of the rubber that results from the accumulation of the fines on the valve seat, larger pebbles and grout will enter the orifice, and when these become lodged in the orifice they permit the cement paste in the mixture to harden around them and cause the nozzle to be permanently clogged.

According to the present invention, there is provided a water introduction device which may function within the teachings of said :Patent No. 2,360,344 during its period of water introduction, and which will more positively close during the period of no water introduction, and with respect to which no concrete can build up which will interfere with the later operation of the device.

It is an object of this invention to provide a water injection device which will be economical to manufacture, which will be free from operating parts that might need frequent repair or replacement and which will be foolproof in its closing action as respects the aforesaid clogging tendencies.

In one of its aspects, the invention resides in the provision of a nozzle having lips of yieldable, elastically deformable material which are movable relative to each other, in case they contact each other, and relative to an insert or seat, if one is placed between the lips, whereby the silt or other line material which may enter the water passage, is worked out of the orifice by the rubbing action of the relatively movable, contacting surfaces. In this manner the orifice is kept tightly closed at all times except when water is being introduced into the drum.

Several embodiments of the invention are illustrated in the accompanying drawings. These embodiments are intended to be illustrative only and further modifications may undoubtedly be made without departing from the spirit of the invention.

In the drawings:

Fig. 1 is a side elevation, partly broken away of a transit concrete mixer showing the preferred disposition of the water injection means in the mixer drum;

Fig, 2 is an enlarged side elevation of one form of the injection means;

Fig. 3 is a sectional view taken at right angles to one of the mixer blades showing'the end of the water injection device in relation to the blade;

Fig. 4 is a plan view of the injection device shown in Figs. 2 and 3;

Fig. 5 is an enlarged side elevation of the discharge portion of the nozzle shown in Fig. 2, taken in section;

Fig. 6 is a view similar to Fig. 5 showing the deflection of the nozzle in one direction;

Fig. 7 is a similar view showing deflection in the other direction;

Fig. 8 is a view similar to Fig. 3 showing a modified form of injection device; 7

Fig. 9 is a section taken on line 9-9 of the device shown in Fig. 8;

Fig. is a side elevation partly in section of another modified form of the invention; and Fig. 11 is an end view of the device shown in Fig. 10.

The mixer drum ll illustrated in Fig. 1 of the drawings is of the type which is widely used at the present time for the mixing in transit of concrete. The drum II is mounted for rotation on an inclined axis with its lower end 12 supporting a tubular shaft l3 which extends axially through the end of the drum. The shaft I3 is supported by a bearing l4 mounted on the mixer frame l5. By making the shaft l3 hollow it is possible to use the shaft not only as a trunnion for supporting the forward end of the drum, but also as a conduit for introducing the requisite mixing water into the drum. Shaft is being integral with the drum, it will rotate therewith, and its connection to the pipe fitting is which leads to the water pump I! should be provided with a stufiing box is to prevent leakage. Pump ll draws its supply of water from the water tank [9 through the conduit member 20.

The frame 15 is adapted for mounting on the rear of a truck and the power for rotating the drum may be derived either from a power takeoif on the truck or from a separate engine. The transmission for effecting this drive is not illustrated in detail as it forms no part of the present invention. A sprocket 2! is illustrated in Fig. I mounted on the head i2, and it will be appreciated that a chain may be employed to drive the drum from the countershaft indicated by the reference character 22.

The rearward portion of the drum is provided with a track 23 which rests on rollers 24 mounted on the frame l5. A charging hopper 25 is arranged to cooperate with an axial opening in the rearward end of the drum to permit the passage of materials therethrough, said charging hopper being movable away from the opening when the materials are to be discharged to permit their reception in a receiving chute 25.

The end of the shaft 13 which extends into the drum is provided with a flange fitting 2'! threaded thereon. A radially extending pipe 28 directed toward the periphery of the drum has an elbow portion at its inner end with a flange fitting 21' which is bolted to the flange fitting 2?. The outer end of pipe 23 is elbow-shaped with a flange 29 at its outer extremity, to which there is secured at a point adjacent the side wall of the drum another flanged fitting 3G. The

of the flange fitting 39 is substantially parallel to the adjacent wall of the drum. The outer end of the piping 28 and so may be firmly secured to the wall of the drum, for instance by the strap 35, one end of which is bolted to the flange 29 and the other end, which is either bolted or welded to the shell of the drum.

Within the drum II are a pair of spirally arranged mixing blades 32 which are designed to lift and tumble the material in the drum, and also because of their spiral contour to propel the materials either forwardly or rearwardly of the drum, depending upon the direction of drum rotation. These blades 32 extend substantially the full length of the drum and the pipe 28 is arranged to extend from the axis of the drum in such a direction that the fitting as may be adjacent one of the blades 32. If the drum is 1'0- tated in the direction of the arrow illustrated in Fig. 3, the terminus of the water supply conduit is preferably arranged as illustrated in Fig. 3 immediately behind the blade 32.

The Water injection device constituting the present invention is generally designated by the numeral 33, and may consist of various modifications, as illustrated in the drawings. In the embodiment illustrated in Figs. 1-4 inclusive, the device 33 consists of a yieldable, deformable member made of rubber or the like having a slot 34 in its flared outer end. The edges of the lips 35 formed by the slot present an end appearance as shown in Fig. 3. The inner end of the member 33 is arranged to fit snugly over a short pipe section 36 threaded on the end of the fitting 30. The member 33 may be vulcanized to the pipe member 36 or it may be held against movement and also against leakage by clamps 36 such as are shown, or by other suitable holding means. The width of the slot 34, as illustrated in Fig. 5, tapers inwardly from the orifice until it corresponds to the diameter of the pipe 38; whereas its height (see Fig. 2) which at the point of merger with the pipe corresponds to the diameter of the pipe, is gradually reduced as it approaches the lip portions with a substantial portion of the two lips pressed tightly together, as illustrated in Fig. 2. Sheets 3? of spring steel imbedded in each of the lip portions tend to keep the lips tightly sealed together and cause the lips to maintain a parallel position when opened. Thus the water may emerge at a uniform velocity throughout the full width of the gap between the lips. The sheets 31 cover approximately the same area as the slot between the lips and stiffen the lips so that in conjunction with tension exerted by the side edges 3'! of the lips, the orifice slot is maintained under substantially uniform closing pressure throughout its entire area.

When water is introduced through the member 33, the pressure of the water forces the lips 35 apart and a stream of water is directed into the space behind the moving blade 32. Because of the shape of the slot 34, a substantially flat stream of water is injected into the cementitious materials, which has greater penetratin power than a stream merging from the periphery of a circular orifice.

When the supply of water is shut off, as by stopping the pump H, the lips are pressed tightly together and effectively prevent any coarse materials in the drum from working back into the water supply conduit. The water emerging from the orifice 34 when the latter is open emerges with such pressure that it is practically impossible for any small stones or grains of sand to lodge between the lips, which would otherwise prevent the lip from sealing tightly when the water was not being admitted into the drum.

As previously stated, however, some very fine particles, mainly particles of cement, may eventually enter the nozzle passageway, despite the pressure of water ejection, and to prevent their accumulation between the lips is an important aspect of the invention.

It will be observed that the lip 35 of the nozzle are not supported and are free to move under the influence of concrete coursing over the blades 32. The stones and other ingredients of the mix striking the flat outer surfaces of the nozzle deflect the end of the nozzle and cause relative movement of the nozzle lips. This movement is depicted diagrammatically and in somewhat of an exaggerated fashion, in Figs. 5 to 7 inclusive, Fig. 5 illustrating the normal or neutral position of the lips, and Figs. 6 and '7 the deflected positions which the nozzle may assume. In Fig. 6, the upper lip A extends beyond the outer edge of the lower lip B, whereas in the position shown in Fig. 7, the lower lip extends beyond the upper lip because of the deflection in the opposite direction. The result of this shortening and lengthenin of the lips relative to each other is a rubbing action between the contacting overlapping edges C of the two lips. This loosens any silt or fine cementitious particles that might be trapped between the lips and prevents such material from building up to an extent where it would interfere with proper nozzle function.

Material engaging the side edges 31 of the nozzle cannot open the lips because of their relative- 1y narrow thickness, the resistance of the rubber to deformation and the presence of the reinforcing springs 3'1.

In order to get the nozzle orifice as close as possible to the back of the blade 32, the axis of the nozzle may be set at a slight angle to the direction of the blade, with the inlet portion, which is necessarily wider than the lips because it surrounds the pipe 36, spaced a slightly greater distance from the blade than the lips. Thus the lips, which are parallel to the blade, may lie closely behind the blade, and water flowing therefrom will follow closely the path formed by the openin of material away from the back side of the blade. In fact the water emerging from the orifice may peel back any material clinging to the blade and cause rapid dispersion of water throughout the length of the drum from the forward to the rearward end thereof.

In the embodiment shown in Figs. 8 and 9, the outer end of the rubber member 33 is forced over an insert designated 39, which is pivotally connected to the pipe section 36, by means of a bolt 40 having an eye portion at its inner end hinged on a pin 4| extending through the pipe 36. The insert 39 is apertured to permit it to be slid over the bolt 40 to a position Where the insert abuts the shoulder 42 on the bolt. A nut 43 threaded on the outer end of the bolt holds the insert firmly in place. With this arrangement, external forces applied on the flat portion of the nozzle may cause it to flex, the insert 39 pivoting about the pin 4|. In this event the lips of the rubber member 33 will rub against the cont-acting surfaces of the insert on account of the foreshortening of the lips similar to the action illustrated in Figs. 6 and 7. Plates of spring steel may also be imbedded in the lips in this modification, the same as they are in the modification first described in order to maintain the lips in tightly sealed engagement with the insert 39 when no water is being supplied from the pump H.

In the modification shown in Figs. and 11, a pipe section 44 having a closed outer end 45 is spaced axially, as indicated at 46, from the end of the pipe section 36, and a tubular rubber section 41 is tightly drawn over the pipe 44 and the end of the fitting 36, its inner end extending a substantial distance beyond the space between the conduit sections. The inner end of the hose 4'! is secured to the pipe 36 either by vulcanizing, by clamps or the like. The outer end of the rubber hose is more or less flush with the end 45 of the pipe and, hence, when water is pumped through the supply conduit 36, the pressure it exerts spreads the outer end of the hose away from the pipe and water passes through the space 46 and thence through the. space between the pipe and the hose into the materials. The pipe section 44 is supported on the conduit 36 by a spring 48 which is welded or otherwise secured to the two pipe sections. This method of mounting the pipe section 44 inserted in the end of the rubber member 4! enables the rubber to flex where it is unsupported internally, and the end of the nozzle will deflect. As a result, if the end of the nozzle illustrated in Fig. 10 should deflect downwardly, the upper portion of the rubber covering slides back; while the lower portion slides forwardly relative to the insert section, thus producing a rubbing action between their contacting surfaces. Hence any materials that may be trapped in the pasageway between them is loosened and worked from the orifice.

The invention having been described, what is claimed is:

1. In concrete mixing apparatus, the combination of a rotatable mixing drum for contain ing a batch of concrete-making solids materials; a water supply conduit extending into said drum; means for supplying water to the outer portion of said conduit; and a self-clearing nozzle provided with a discharge passageway communicating with said conduit, and having a resilient transversely deflectible portion provided with opposed surfaces normally yieldably contacting one another for a substantial distance to close the passageway against the discharge of water and entry of the solids between them, said nozzle being carried by the inner portion of the conduit in a position to be buried in the solids, whereby movements of the latter during rotation of the drum will deflect said defiectible nozzle portion and produce a rubbing action between said opposed surfaces to dislodge any solids which may have worked their way between and adhered to such surfaces.

2. In apparatus for mixing concrete, a rotatable mixing drum for receiving and mixing a batch of concrete-making, solid materials, a water supplying conduit extending into said drum for supplying water to the mix, and a selfclearing nozzle connected with said conduit in position to be buried in the solids of the batch being mixed, said nozzle having a resilient, transversely-deflectible discharge portion constituting a discharge passageway communicating with said water supplying conduit and terminating in opposed surfaces yieldably contacting each other for a substantial distance forming a slot adapted to open under pressure for the discharge of water while normally closed against the entry of solid materials, the arrangement being such that flexing of said resilient nozzle portion by movements of the solid materials during mixing causes foreshortening of one or the other of said opposed surfaces producing rubbing action between them to dislodge any solid materials which may have worked their way between and adhered to said surfaces.

LOUIS G. HILKEMEIER.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,992,518 Werner Feb. 26, 1935 2,303,992 Frazer et al. Dec. 1, 1942 2,360,344 Hilkemeier Oct. 17, 1944 2,373,555 Folke Apr. 10, 1945 FOREIGN PATENTS Number Country Date 9,653 Great Britain May 17, 1894 196.960 Great Britain May 7. 192a

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