US2398267A - Apparatus for forming blocks of concrete or other hardening material - Google Patents

Description

,Apnl 9, 1946. F. A. WILLIAMS 2, 7

APPARATUS FOR FORMING BLOCKS OF CONCRETE OR OTHER HARDENING MATERIAL I Filed Oct. 1, 1942 r Patented Apr. 9, 1946 APPARATUS FOR FORMING BLOCKS OF CONCRETE OR OTHER HARDENING MA- TERIAL Francis A. Williams, Toronto, Ontario, Canada, assignor of one-half to New-Era Walls, Limited, and one-half to Cyclops Commercial and Construction Co. Ltd, both of Toronto, Ontario,

Canada Application October 1, 1942, Serial No. 460,462

1 Claim.

This invention relates to the manufacture of blocks of concrete or other plastic material used in the construction of the walls of buildings or other structures. The material for such building blocks is usually fed into an individual form or mold, compacted in the mold by (1) tamping or (2) vibrating and, after compacting has been completed, removed from the mold in a separate operation.

As the present invention is based on vibrating the material and does not employ tamping, it is unnecessary to discuss any of the older methods or apparatus in which tamping is employed in the present application.

In existing machines where the compacting is effected by vibration, while the vibration affects the whole system, including the, mold as well as the cores,,such vibration does not aifect equally all the strata of the material in the moldand the lower part, due to the weight of the material above it, is always compacted to a greater extent than the upper portion. In many cases therefore this upper portion has to be further compacted by other means, usually pressure, which makes the apparatus and its operation more complicated.

Another old and widely used method of compacting concrete in the mold of a block-making machine or in any form into which the concrete has been poured, is that of introducing vibrating bodies, usually of cylindrical form, into the concrete producing an internal vibration of the mass, and withdrawing the vibrating bodies after a certain time. This principle is used in many cases in producing concrete structures (reinforced or otherwise) both where the material is cast in its permanent location or where the material is cast in special machines for use elsewhere. It is obvious that the fact that the vibrating bodies in these cases penetrate the material from one side, mostly from above and leave it later by withdrawal in the opposite direction has the consequence that the surface of the concrete or other plastic material which has been eifected first by the entering vibrator is also the last one to be left by the withdrawing device and so gets the most amount of A vibration, while the other strata receive less and less vibration, the deeper they are in the material. The method of vibration used with the present invention provides exactly the=same amount of vibration for all of the strata. This is being attained by an arrangement in which the plastic material passes through a vibrating system in a continuous flow in one direction. In the vibrating system the position of the cores and mold relative to each other, remains unchanged ex cept as the result of the very small amount of vibration mentioned.

5 The principal object of the present invention is to provide a simple, cheap, rapidly and economically operated apparatus by means of which various types of building blocks may be manufactured. In the improved apparatus the wet mixture of the material is fed into the upper end of a bottomless mold and is extruded downwardly incompacted condition from the open lower'end of the mold thus providing in effect a continuous process by means of which a continuous mass of compacted material of the cross sectional shape of the desired block or structure is extruded from the mold for division into sections of the desired height to form the individual blocks; V The material after being fed into the, mold is immediately subjected to agitation by means of vibrating cores and/or a vibrating mold, which agitation has the three fold object of (1) causing the material to pass downwardly in the mold, (2)

to compact the material so that the blocks formed from thematerial have the necessary. densityand strength and (3) to free the new block from the mold by counteracting the friction between the walls of the mold and cores against the concrete,

possible. I I

The method of vibrating the cores and/or bottomless mold has the following advantages.

1. Every stratum of material passing down the vibrating core receives an equal amount of vibration. 2. No pressure from above is needed, since the particles before leaving the mold bottom have suflicient weight of concrete above them to prevent. them from bouncing as they would if there is no load upon them, but the agitation of the upper material causes it to move downwardly, thus exerting a pressure on the material below it and tending to further compact the latter.

ically free the concrete to be extruded so that no separate operation is needed to overcomethe friction between concrete and mold. This friction due to the tightly compacted state of the concrete is always so great, that thepower required to free the new block from the mold is very considerable with the existing machines.

The object is obtained by means of the constructions hereinafter described and illustrated in as the accompanying drawing in which:

making a downward free extrusion of the block 3. The vibrating mold and/or cores automat- A Fig. 1 is a plan view of the improved apparatus.

Fig. 2 a longitudinal section along the line 22 in Fig. 1. i

Fig. 3 a cross section along the line 33 in Fi 1.

Fig. 4 a plan view of a modified form of knife.

Fig. 5 a side elevation, partly broken away, showing a modified arrangement of agitating the cores.

In the drawing, like numerals of reference indicate corresponding parts in the different figures.

l indicates a supporting frame which may be made of any suitable shape and material to support the various working parts of the apparatus.

Supported in this frame adjacent one end thereof is a form or mold comprising side members 2 end members 3 the upper portion of which is arranged to receive the wet mixture of which the blocks are formed, and its bottom is open to allow the shaped mass to be extruded therefrom.

While building blocks of concrete or other plastic materials are sometimes made solid as hereinafter referred to, it is usual to provide openings which have not only the purpose of saving material, but the more important purpose of providing air spaces in the wall to provide insula tion.

These openings are formed by means of suitable cores arranged intermediate the front and back of the mold or form. In the construction shown, three full cores 4, and two half cores 5 are shown.

As set out in the preamble of this specification it is desired to immediately subject the freshly poured material to vibration to compact the material to an extent suflicient to give the extruded material sufficient strength and density required in the finished blocks. This vibration, as suggested inthe preamble of the specification may be effected by vibrating the mold, or the cores, .or both, and in Figs. 1, 2 and 3 of the drawing, the mold and cores are all arranged to vibrate.

The method of mounting the mold and core members and eifecting their agitation may be aranged in various ways. The mold is shown resiliently cushioned in the frame I, and in Figs. 1, 2 and 3, the mold and cores are shown as mounted on two longitudinal bars 6, which bars are supported in a bearing 1 in one end of the frame I, and a bearing 8 in the opposite end of the frame. These bearings are formed of a suitable resilient material, such as rubber, so that the bars 6 may be vibrated, which in turn causes the vibration of the mold and cores. Metal springs may, of course, be substituted for the rubber in the bearings.

These bars are connected together by a rod 13 so that the bars 6 may be vibrated in synchronism, and to cause the agitation or vibration of the bars 6, a short tubular shaft!) is mounted on bearings on the rod I3 between the bars 6. On this shaft is mounted a pulley l0, which is driven by a belt H from a motor l2. This shaft has mounted thereon a pair of eccentric weights M, which weights when the shaft 9 is rapidly rotated set up a vibration of the bars 5 and in turn the cores 5, and the mold. Due to the bars 6 being resiliently mounted it will be seen that an effective vibration of the bars 6 and the parts carried thereby, will be obtained. It will be evident that in some cases the cores only may be vibrated and the mold remain stationary, while in other cases the mold might be vibrated and the cores remain stationary.

The wet material is fed into the upper end of the mold above the top of the cores by means of the chute or guide iii. In order that the material will not remain on the upper end of the cores, the latter have their tops specially shaped, one suitable method being to incline or bevel the upper ends as shown in Fig. 3. This arrangement not only facilitates the movement of the material from the core tops but also is carefully chosen so as to avoid any gradual building up of material by arching which would tend to prevent downward travel of the material in the mold.

Different materials, different degrees of plasticity of the material and different methods of feeding the material will require appropriate changes in the shape of the 'core tops, but the principle of a shaped top remains the same. The bars 6, being comparatively thin, although sufiiciently strong for this purpose, offer little resistance to the downward travel of the material, and any space caused thereby is quickly filled in as the material in the mold is agitated by the cores and/or mold.

The agitation or vibration of the mold and/or cores not only compacts the material but also actually assists the downward movement of the material by gravity, thus counteracting any friction between the compacted material, and the walls of the mold or the cores and thus avoiding the use of any secondary means to extrude the compacted material from the mold. This vibration is also used to regulate the feeding of fresh material into the mold. It is found that hoppers with steep feed chute are not feasible, as experiments show that with such steep chutes, the material tends to arch above the vibration Zone and therefore stops feeding. On the other hand it is found that with a feed chute which would not feed due to its lack of suflicient inclination the vibration tends to pull the material from the lower part of the hopper into the mold to replace the material moving downwardly in the mold. and causing the material, which was piled up in the upper part of the chute, to slide down to take the place of the material which was carried away by the vibrator.

The mold and also the cores are preferably of greater depth than the depth of the finished block so as to provide for greater travel of the material during the compacting operation, and further to give the necessary extra space for the additional material to give the necessary weight required to prevent any loosening ofthe material in the upper part of the block length about to be extruded from the mold.

The-shaped material as it emerges from the lower end of the mold rests upon a pallet [6, which pallet rests upon a platform I! movable vertically in the frame i. The platform I! is provided with mechanism (preferably a brake) which controls its descent with the loaded pallet l6 thereon. When the platform with the loaded tray has descended to the desired extent, the downward movement of the material in at least the lower part of the mold where compacting is substantially completed will cease due to being stopped by the knives hereinafter referred to. The control of the descent of the platform I! with the pallet I6 is particularly important as such descent regulates the time the moving material is subjected to the vibration and assures that .ordinating the rate of feed, the compacting and the rate of extrusion, it will be evident that a substantially continuous operation of the apparatus may be obtained.

The extruded portion of the mass of compacted material below the mold, the height of which is equal to the height "of the desired block, is then separated from the material above it in order that the pallet with the extruded material thereon may be removed. The position'of the line of separation of course will depend on the height desired for the block, but said line will be located, as indicated in Fig. 3, just above the lower end of the core, and after separation the platform I! is dropped a further distance as indicated in dotted lines in Fig. 3, to free the upper end of the block from the lower end of the core. j

The separation is effected by a pair of knife members l8. These members l8, as indicated in- Fig. l are formed as sharp edged plates, having their edges provided with U-shaped notches to receive the correspondingly shaped cores 5.

As an alternative, the cutting portions of the knife members l8 may be formed, as indicated in Fig. 4, as a series of sharp prongs l8,

These knife members l8 are operable in guideways in the frame I and are shown with hand grips l9 for manual operation. It will be evident of course that other special means may be provided for advancing and retracting the knives.

It will be noticed in Fig. 1 that the notches in the knife members are very slightly larger than the cores. This is to provide room for a forward and backward slicing motion of the knives and to prevent the vibrating cores from striking the edges of the knives. The knives, due to the pressure of the material above them, cannot loosen the upper stratum of the new block as in the case of simple shaping and the pressure material above them, leave the block with a finished upper surface, thus avoiding the necessity of any additional tamping or pressure which might otherwise be necessary to provide the block with a satisfactory surface.

When the knife members have been operated to sever the block from the mass, the platform with the pallet and the block thereon are dropped to free the block from the lower ends of the cores, and the pallet with the block thereon are removed, the knife members holding the mass temporarily from descending. A fresh pallet is then placed upon theplatform, which is then quickly raised to position the pallet below the knives. The knives are then retracted, and the compacted mass again starts descending to extrude a fresh block length.

Contrary to all previous methods in which the molds are first filled and then emptied for refilling, the present process is a continuous one, because a fresh block is being made in the mold even at the same time as a compacted one is being extruded, and the fact that the extrusion is intermittently stopped by the knives, does not stop the continuous operation of the process as a whole, because the temporary resistance to the downward trend caused by the knives only helps in the compacting of the upper block. It will be noted that the mold is never empty except at the close of operations.

In some cases it may be desired to give to one or more faces of the blocks, a special pattern or configuration. In this case the mold will be made slightly larger, and special face platesin a indicated at the left hand side of the mold in Fig. 3 may be employed. These face plates will travel downwardly with the mass, and each face plate may remain with its particular block as long as necessary for the purpose desired.

To insure positive downward travel of the face plates, the lowermost one ma be connected to the pallet, and the upper ones to one another. The connections between the sections, are arranged to provide a narrow space between the sections, as indicated at 20, to permit-the entrance of the knife. i 1

In such case, in removing the block, the face plate will be disconnected from the face plate above it, and the face plate in the bottom of-the mold will be connected with the fresh pallet being positioned to receive the next block.

This use of travelling face plates enables the making of blocks with rough or patterned faces, which faces the friction in the downward travel of the material would otherwise destroy. The face plates may have their working surfaces treated in the manner disclosed in a pending application No. 353,820 filed August 23, 1940 for the purpose of giving the blocks a smooth or glossy surface.

As stated above the method of agitating or vibrating the bars 6 shown in Figs. 1 and 2 is only one of the several ways of accomplishing the result. In Fig. 5 the cores are shown, secured together by bars 6A and the central core has positioned thereon and is supported from a vertical cylindrical shell in which is located automatic vibrating device 22 which may be operated in any convenient manner.

As stated above any suitable means may be provided for controlling the descent of the platform I! in Fig. 3 of the drawing, a curved braking member 23 is pivoted on the frame and extends through an opening in the platform IT, to frictionall engage the edge of the latter. This braking member 23 is provided with an extension 24 adapted to be operated by the foot to cause the member 23 to frictionally engage the platform to regulate the rate of its descent. Also pivoted on the frame is a lever member 25 which normally occupies a position in which a stop 26 thereon is in position to engage a downward extension of the platform I1, while the severing of a block length is effected. The member 25 may then be rocked to disengage the stop 26' from the platform, to allow the latter to descend to engage the substantially horizontally directed part of said lever member 25 to hold the plat form while the severed block with its pallet is removed from the platform. The fresh pallet is then placed on the platform and the latter raised to position to receive a fresh block. The further dropping of the platform tounloading position is of course controlled also by the block.

It will be seen from the above description that a very simple, fast moving and economical apparatus has been devised for carrying out a substantiallv continuous process of forming blocks by feeding the material into the mold, compacting said material while'in the mold and causing it to travel there-through vibrating the mold and/or the cores, which form the insulating openings-in the blocks, utilizing the weight of the freshly fed material to assist in the compacting of the lower material and extruding the material after it has been compacted, to the desired density on to supporting pallets, the downward operation of which pallets regulate the rate of extrusion of the compacted material, the necessary height ofthe ma-' terial above each pallet being divided from the main mass to form a block of the desired size. 7

It has also been pointed out that vibrating the material causes it to be extruded freely and uniformly, overcoming the friction between material and mold. Properly compacted material binds itself so tightly in a mold that in other machines strong pressure is required to force the newly formed block from the mold in a separate operation.

In some cases it may be desired to make solid blocks, in which case the cores 4 and 5 will be omitted, and in this case also, the vibration of the material may be effected by means of the mold only as provided for above.

' It may also be desirable to restrict the vibration of the mold relative to the core, and this result may be obtained by applying resilient cushions 21 between the bars 6 and the mold, as indicated in Fig. 3.

In the specification and claims, the word.

block is used in a broad sense as including flat slabs, cylinders or other shapes which lend themselves for manufacture by extrusion in the manner set forth'above.

What I claim as my invention is:

In apparatus for molding units of concrete or other plastic hardening material, the combination of a bottomless mold member; a core member in said mold; means for feeding material into the upper portion of said mold, a plurality of surface-affecting inner face members arranged edge to edge and arranged to slidably engage the inner face of the mold to travel through said mold with the material.

' FRANCIS A. WILLIAMS.

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