US2017439A

US2017439A - Cement grout mixing machine

Info

Publication number: US2017439A
Application number: US638756A
Authority: US
Inventors: George W Grayson; Ronald B Hinder; John T Mckee; Edmund P Weber
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-10-31
Filing date: 1932-10-20
Publication date: 1935-10-15
Anticipated expiration: 1952-10-15
Also published as: GB404780A

Description

Oct. 15, 1935., e. w. GRAYSON CEMENT GROUT MIXING MACHINE Filed Oct. 20, 1932 2 Sheets-Sheet l 'Nvenncn; GEORGE W N wow Gmwso BY \us gnome": 74

Oct. 15, 1935. e. w. G RAYSON CEMENT GROUT MIXING MACHINE 2 Sheets-Sheet 2 6 6 v 414 m SQW/u HB v o 6 4! V0 a H m 0 m W m Z W Q 4 n V Y J m 7 8 I n 8 u a J 4 l 3 H u o H a M n 5 2 7 2 2 4 n km 3 o 5 4 o 3 Patented on. 1 5, 1935 UNITED STATES 2,017,439 CEMENT enoo'r mxmo MACHINE George Wentworth Grayson,

Australia, assignor of one-fourth to Sydney,

Darling Point, near Ronald Butler Hinder, Lindfield, near Sydney,

Australia,

one-fourth to John Thomas McKee,

Sydney, Australia, and one-fourth to Edmund Percival Weber, Australia Turramuna,

near Sydney,

Applicationbctober 20, 1932, Serial No. 638,756

2 Claims.

This invention relates to cement grout mixing machines of the type having on a suitable framing or chassis a proportioning mill constituted of a hopper or bin divided into a plurality of compartments (say two, one for cement and the other for sand) by division walls and having sloping side walls to discharge orifices adjacent each other and having revolvable radial vanes (the spaces between which constitute receptacles) on spindles in the hopper discharge orifices to apportion the ingredients from each hopper to mixing and distributing apparatus. The apportioning of the discharge from the'several compartments in relation to each other as for example the cement 5 and sand in such machines has hitherto been effected by the insertion of proportion plates between the vanes thereby reducing the volumetric capacity of the mentioned receptacles and practice has shown that such proportioning mecha- 20 nism is not as effective as the mixing of cement grout requires. It is essential in the mixing of water cement sand'and other materials as may be required for a grout that the quantities of each and particularly the cement and sand be main- 25 tained strictly in predetermined proportions. The mechanism used heretofore for this purpose delivers the several ingredients in the predetermined proportions only so long as the weight per unit volume of the ingredients-particularly the sand-remain constant. In practice the weight per unit volume of the sand varies considerably as for instance according to the moisture content or aeration thereof and the machine requires altering for every appreciable variation. This entails stopping the machine and fitting other proportion plates and again working the machine and testing the mix and so on working by trial and error until the correct mix is attained. The

material and time wasted during this process of testing is obviously considerable and if such test material is used it may be so weakened as to seriously impair the strength of the ultimate strucmm.

It is only after the work has been completed that certain sections of the structure would show signs of failing under service conditions and these failings will in all probability be in sections coinciding with change in weight per unit volume of sand which change would almost invariably have been caused by weather or such other circumstances as would vary its moisture or air content. Y

Tests of the output from a machine of the type defined gave a variation on different daysof the proportion from those to which the machine was Australia October 31, 1931 set for job dry materials (i. e. one part cement to two and one half parts sand (1-2 by volume) of as much as from 11% to l to 4; this was due in this case to weather conditions altering the moisture content of the sand and rendering it 5 dry at one period and comparatively wet at another.

Like the proportioning apparatus the agitating and distributing apparatus on machines hitherto used has not been as eiiective as is desirable. It is necessary'that the distributor convey the premixed grout from the mixing apparatus to the point of applicationin an even and constant flow and in a state of continuous agitation to prevent segregation of the grout constituents and that the time taken in so conveying it (till deposited in a mass of broken metal as in a road bed) be maintained as predetermined to enable complete colloidal union of the grout constituents.

While machines hitherto have provided for the continuous agitation of the grout they have not provided readily adjustable mechanism to ensure an even and constant flow of the mix and the maintenance of a predetermined duration of time to convey said mix along the distributor.

The disability has been due in a large measure to the fact that it has not been practicable to keep the angle of inclination of the distributor in relation to the horizontal constant when in use. For example when the machine is working on an incline as on a road it has not been practicable with mechanism hitherto available to swing the distributor from one extreme position to the other that is through an angle of 180 without varying 1 such angle of inclination.

Now this invention has been devised to overcome the stated difficulties by providing simple mechanism which will enable say an intelligent foreman or like workman to carry out the supervision and correction of the variations of a cement and sand mix and to maintain an even and constant flow of it as part of his general duties while the machine is running and this without 4 any interruption to the continuity of the working of the machine.

In order that the invention may be readily carried into practical effect it will now be described with reference to the drawings accompanying and forming part of this complete specification. Fig. 1 is a schematic side elevation of a cement grout mixing machine embodying these present improvements; Fig. 2 is a plan thereof; Fig. 3 is a diagrammatic layout of proportioning mill driving gears; Fig. 4 is a part sectional elevation of a p proportioning mill, and Fig. 5 is a section on line 5.-5 Fig. 1, while Fig. 6 is a fragmentary end elevation thereof;

The machine is constituted of a wheeled chassis 5 with or without ordinary steering mechanism and propelling mechanism (not shown). A prime motor 8 and proportioning mill I are mounted on the chassis 5. One end of a mixing trough 8 is juxtaposed below said mill and at its other end said trough has a universal' union or discharge 9 to a distributor l having outlet II with spreading chute l2. The prime motor 8 has a drive through intermediate gears to shaft I 3 and said shaft l3 preferably has a take off ll to a machine propelling mechanism not shown. Pinion I on said shaft I 3 drives through intermediate gear l8 mill-gears l1 and I8 and agitator-gears l9 and 20 and said shaft I3 is coupled to or is integral with shaft 2| within the mixing trough 8. This shaft 2| extends the full length of the mixing trough 8 having suitable hearings in the ends thereof and has helically set mixing paddles 22 mounted thereon and on the rear end has a bevel pinion 23 within universal coupling 24 meshing a crown wheel 25 which meshes a bevel pinion 26 on telescopic shaft 21 which through gearing 28 operates helically set paddle conveyor 29 in the distributor l0. Clutches to operate the several drives are incorporated as well understood. Slipping clutches are also incorporated as well understood to prevent breakage of the working parts in case of a jam in the materials.

The proportioning mill (Figs. 3, 4, 5 and 6) is constituted of end walls 38 and 3! having at top hoppers 32 and 33 (for cement and sand) wherein are

agitators

34 and 35 rotated by gears l9 and 28 respectively. Across the hopper discharge orifices are shafts 36 and 31 (in suitable end bearings) whereon are mounted sets of vanes 38 and 39 (the spaces between which constitute allocating receptacles) keyed to or integral with

shafts

38 and 37 which are rotated by ears I! and I8. The

shafts

36 and 31 and also the shaft 2| are each provided with deflector discs 40 which prevent any cement or sand lodging in their respective bearings.

On the

hoppers

32 and 33 are sealing and guiding plates 4i and 42 hinged at their top edges as at 43 and adapted to be firmly pressed against the peripheral edges of the

vanes

38 and 38 by compression springs 48 on the ends of arms 45 ailixed to said plates Cl and 82. These plates are incorporated to prevent the cement or sand discharging other than from the vanes receptacles and the springs 84 permit of large size particles as stones to pass between vanes and plates ll and 42 without fracturing said plates.

Mounted on the

shafts

36 and 31 are longi tudinally

reciprocatable proportioning cylinders

46 and 41 adapted to partly occlude the apertures of the allocating receptacles and said cylinders are of approximately. the same diameter as the

vanes

38 and 39 and have longitudinal slots 48 wherein said vanes are adapted to slide home as said proportioning cylinders are advanced across the mouth of the hoppers. These cylinders and 41 have at one end bearings 49 slidable on the shafts-38 and 31 and have at their other ends 'quadrantal supports 58 adapted to slidably fit between the vanes 88 and 38. The proportioning cylinders 88 and I! have end collars 5| having shifting dogs 52 in grooves thereon said dogs having integral carrier nuts 53 on screwed spindles 54 in end-

bearings

55 and 58. The nuts 53 have pointers 81 thereon juxtaposed a scale 58 graduated sayjin tenths and hundredths and the spindles 54"a're provided with turning wheels 59..

The

spindles

38 and 39 have vibrators at the outer ends thereof comprised of cup cam 60 en- 5 .hinged to bracket 18 and has its top end ll screwed and passing freely through a trunnion i2 and is provided with wheel nut 13. The trunnion I2 is freely rotatable in the top of a post H and said trunnion is compelled to rotate with the distributor ID by said stay 15. The post 14 is bifurcated at bottom and is hinged in bearings l6 and its position is adjustable by stay 11 which is comprised of a screw 18 (having turn wheel 19) homing within a nut 80 on a divergent stay rod 8| pivoted in bearings 82 one .on either side of the chassis 8.

A water supply for the making of the grout comprises a tank 83 having a float operated inlet valve and having outlet pipe 83 with regulating valve 85 thereon and having delivery nozzle 86 directed into the mixing trough 8 at 30.

about the position shown.

It is to be clearly understood that though the cement and sand allocators are both described as having proportioning mechanism incorporated therewith the machine may be efiectively operated with such mechanism on the sand allocator only. Further though the machine has been described as having cement and sand proportioning mechanism only it may well have proportioning mechanism for such other ingredients that it may be desired to incorporate in the grout.

In use the distributor in is first set at the required angle of inclination by operation of the wheels H and 79 but the post 14 mus-t be vertical to allow distributor ID to always maintain a constant angle with the vertical. The machine driving mechanism is set in motion and cement and sand is fed into the hoppers other materials being added as required or other hoppers incorporated in the machine therefore. For the production of an efiective grout the sand should be of such fineness that it will all pass through a fine mesh sieve, say 30 mesh, or if coarse sand is used it should be amalgamated with some fine material as fine sands or a diatomaceous earth or hydrated lime so that colloidal union of the ingredients is facilitated. The proportioning cylinders are positioned on the vanes-so that only the required proportions of cement and sand (and other ma- 80' terial required) 'may-pass-through said-hoppers. The manipulation of saidvcylinders will be more fully described later herein. :The agitators 34 35 keep the cement sand and other admixture moving downward toward the apportioning mechmaterials under all conditions however inducedvibratory mechanism-in this case hammers '63

strike spindles

38 and 31 thereby causing the vanes 38-39 to vibrate with sufilcient intensity to completely discharge the apportioned material.

The number of vibratory blows administered to constant level thereof in the tank maintained by the float operated valve the flowthereof from the nozzles 86 is uniform. h

The apportioned materials and water pass from respective hoppers and tank into the mixing trough 8 where the revolving mixing paddles thoroughly amalgamate the ingredients and travel the mix along to the discharge 9. The'now formed cement grout passes through the discharge 9 to the distributor III which is adjusted so that it may be operated to travel on the same horizontal plane irrespective of the angle of inclination of the machine. This is efiected by adjusting the length of the stay 8| to position the post 14 vertical. Having the distributor Ill adjusted as before stated an'even and constant flow of the mix is maintained while the paddles of the conveyor 2! keep the mix in a state of continuous agitation and prevents s'egregation of the ingredients. The angle of inclina tion of the distributor in being constant the mix I.

is conveyed therealong mechanically and the time taken is in accordance with a predetermined speed of the revolution of the conveyor and is sufficient to insure complete colloidal union of the grout constituents.- The proportions of cement and sand are-controlled under field conditions in the following manner. For example say the specificationdemands the proportions of one cement to'two and one half of sand in a dry condition (1 -2 the pointer on the cement shutter screw is set to read 30 on the scale and the position of the pointer on the sand shutter screw should then be adjusted to read 30 2V =75 on the scale. If the sand was absolutely dry that is devoid of any moisture content (which is very rare in practical conditions) the mix would be one cement to two and one half sand as per specification but as a very small moisture-content increases the sand bulk a correction will have to be made to one of the settings as hereinafter described.

It is known that sand increases in bulk when moist but when completely inundated resumes i-ts dry volume that is practically the same volume as when ovenfdried. A measuring glass preferably about II or I! inches in length and one to two and the full extent of its radial a half inches in diameter graduated into tenths and hundredths is filled up to'say the 50 mark with the sand to be used and then filled with water. The glass is thoroughly, shaken and then placed in a stationary upright position to allow the sand to settle in the water. The sand will set-' I tle back to a. mark which would have been its position had it been dry 'when first put into the glass. The difference between the two readings shows the diflerence in bulk due to moisture content and the inundated readings divided by the first read ing (viz. 50) multiplied by will give the percentage increase of bulk due to moisture content and therefore the pointer on the sand scale will have to be moved to counteract .the effect of bulking as in following example correction:-

subtracted from 50 should equal of the grout disclosed that the proportions were not correct and the glass readings were top 50 After settling thereading at the top of the sand (inundated) is say 40 so that the percentage difference of the sand in bulk or volume due to moisture content is 50 I: I6 1]X1(l0-- 25% that is the total bulk or volume of sand passing through the sand allocator is 25% less than that desired and this is due to moisture content. Therefore the reading on the sand scale will have to be increased as follows. The sand scale reading 75 will'have to be increased 25% to make al-v lowance for the moisture conteiit in the sand and the correction to the reading (that is the new reading) will be The proportioning of the mill will now be correct the scales now reading 30 cement and 94 sand.

A check of the proportions of the grout as mixed should be taken as delivered from the machine on to the road after the manner of the example below and after settling the sand will go to the bottom and the cement to the top the line between. the two being sharp and clearly defined. This is due to the difference in the specific gravities of sand and cement therefore the reading at the top of the sand that is the line dividing the sand and cement gives the quantity of sand 'lOI .in the glass and the same reading subtracted from this being the amount of sand and this reading 45 showing the amount of cement so that. 35.715 50 divided by l4.285=2 which are the correct proportions viz. one part of cement to two and one half sand.

Now. suppose that the test of proportions and at the division between cement and sand 34 so the quantity of cement==50-34=i6 and the sand quantity is 34 then the proportion ratio is 34 divided by 16:2.122 that is one part cement 60 to 2.122 parts of sand instead of 1-2%; there- I fore the mix is richer than the specification calls for by ---1]X-10=17- 79%. 4 65 The reading on the cement scale should therefore be reduced say 18%. The reading 30 oppo-- site the cement pointer will have to be reduced so changing the: settings on themachine they now Again suppose that the test of theproportions of the grout test disclosed too lean a mixture the glass readings being top and at the division between the cement and sand 38 then the quantity of cement=50-38=12 the sand quantity bethis being so the reading 30 opposite the cement pointer will have to be increased by 26.7% viz.

30 X 26.7 so that the settings on the machine now read 38 for the cement pointer and the sand pointer remains unchanged viz. 94.

I claim:

1. In a cement mixing machine the combination including a distributing channel, a shaft rotatably mounted within the distributing channel, a plurality of helically arranged agitating and conveying blades on the shaft within the distributing channel, means for maintaining a particular inclination of the agitating and distributing channel includinga post hinged at one end to the machine and mounted in the same vertical axis as the axis of radiation of the distributing channel, a swivel head on the post, an adjustable guy extending from the post supporting said distributing channel, means for maintaining the swivel head in alignment with the supporting guy, an adjustable stay hinged to the machine and the said post, and means to rotate the agitator in the channel.

2. In a cement mixing machine, the combination including a proportioning mill comprising a hopper for sand and a hopper for cement, a rotatably mounted agitator within each of the hopdle for each shutter rotatably mounted parallel to, the axis of the shutter, a traversing nut on each spindle, means for connecting the shutter and the traversing nut associated therewith, a aduated scale above the threaded spindle, a vibrator timed to strike the shaft upon which the veins are mounted when each cavity between a pair of veins is open to the discharge of the hopper, a mixing channel disposed immediately below the discharge of 'said proportioning mill, a shaft rotatably mounted within the channel, a plurality of helical mixing and conveying blades mounted on the shaft, an agitating and distributing channel, a swivel connection between said mixing channel and said agitating and distributing channel, means for maintaining a particular inclination of the agitating and distributing channel including a post hinged at one end to the machine and mounted in the same vertical axis as the axis of radiation of the distributing channel, a swivel head on the post, an adjustable guide supporting said distributing channel, means for maintaining the swivel head in alignment with the supporting guide, and an adjustable stay hinged to the machine and the said post, means to rotate the agitators in the channels and means for operating said vibrator.

I GEORGE WENI'WORTH GRAYSON.