US1304619A

US1304619A - Method fob conveying concrete aggregate

Info

Publication number: US1304619A
Authority: US
Publication date: 1919-05-27
Anticipated expiration: 1936-05-27

Description

H. 0. STAMP.

METHOD FOR CONVEYING CONCRETE AGGREGATE. l

APPLICATION FILED FEB. 8. 19m

1,304,619. Patented May 27, 1919.

HUGO O. STAMP, OF MILWAUKEE, WISCONSIN.

METHOD FOR CONVEYING CONCRETE AGGREGATE.

Specification of Letters Patent. Patented May 2'7, 1919.

Application filed February 8, 1917. Serial No. 147,285.

- of Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements m- Methods for Conveying Concrete Aggregate; and I do hereby declare that the following is a full,clear, and exact description thereof.

Myinvention relates to new and useful improvements in means for conveying concrete aggregate to a mixing machine from storage piles along the roadway.

In view of the temporary nature of general concrete conveying operations, it is desirable to provide a means for conveying involving an apparatus which is cheap and easily portable.

Concrete aggregate usually comprises different ingredients and these ingredients must be delivered in successive batches to the concrete mixer in definite relative proportions.

A further consideration is the relatively large volume of aggregate necessarily stored under practical conditions adjacent the mixer, the mixing capacity of which in many instances amounts to a cubic yard of sand and gravelper minute.

It is primarily the object of my invention to provide a method for conveying concrete aggregate in a manner adv antageously meeting all of the aforementioned considerations.

It is more particularly an object of my invention to provide a method of conveying concrete aggregate involving the conveying movement of the aggregate by a single conveyer conveying both materials continually, thereby permitting a minimum storage space between the several steps after the materials leave the ground storage piles and thereby allowing a construction of minimum height to pass under trolley wires, tunnels, etc., Without dismantling.

Figure 1 illustrates diagrammatically one form of apparatus adapted for carrying out my improved method of conveying concrete aggregate.

Fig. 2 is a plan view of the horizontal conveyer portion of said apparatus, showing the relative disposition of aggregate ingredients there adjacent.

Referring now more particularly to thedrawing, '5 designates the receiving portlon of a concrete mixer, and arranged to discharge thereinto ar .pair of measuring hoppers 6 and 7 respeiitively, controlled by suitable valves 8 in their bottom, and these hoppers are of a relative capacity corresponding to the desired proportion of sand and gravel to be discharged into the mixer, nd said hoppers may be variable in capacity f deslred to vary the proportion. Disposed above and adapted to discharge into the measuring hoppers 6 and 7 are a pair of storage bins 9 and 10 respectively, having outlet valves 11 and disposedthereabove is an inclined screen 12 suspended by pivoted hanger arms 13 and connected with an oscillatory pitman 14 mounted eccentrically on a suitable driven wheel 15. As shown, the screen is dlsposed over t e bin 10, whereby material passing through its mesh will fall thereinto, and the lower end of the screen is dis osed adjacent one edge of the bin 10 where y material passing over the screen Will discharge into said bin 9. For conveying concrete aggregate to the screen, an elevator 16 is arranged to discharge thereonto and has a boot 17 at its lower end for receiving the discharge of a horizontal conveyer 18 which extends a considerable distance along the ground and adapted to lie between plles of aggregate ingredients. along the road-way.

In carrying out my improved method it should be understood that it is adapted to economically handle the several finished products which may be termed aggregate, and, as described, the several finished prod nets, in this instance sand and gravel, are storedon the ground in indiscriminate piles along lines paralleling the conveyer 18,-the ground piles of the congregated mass are then fed to the conveyer in 'a continuous stream and in roughly proportionate quantities more or less mixed and from this conveyer they are raised to the desired height by an elevator 16. After reaching this elevation the mass-Will then flow by gravity through several steps of the process to the mixer. It is first discharged upon the oscillating screen 12,-whereby the sand and gravel are separated and caused to flow in'individual streams to equalizing bins 9 and 10 which serve as momentary dams for each finished product. Thus the bins9 and 10 serve to compensate for temporary varia tions, in relative amounts of differing ingredients fed to the conveyer 18 and to said bins by the conveyer. From these bins the separated finished products are released and flow into hoppers 6 and 7 Where they are held in suspension and measured. Thereafter the measured finished products are released and caused to flow together coincident to their discharge into the mixer proper. By thus conveying the two materials in a stream, which is practically a continuous process, large quantities of material may be moved with only a single conveyer and the bins 9 and 10 need be of only sufiicient capacity to compensate for any temporary variation in the supply of their respective materials thereto by depositing said respective materials in roughly proportionate quantities on the conveyer 1 8 and also to provide a means for holding the materials while the measuring bins 6 and 7 are discharging. Thus they act only as reservoirs of small capacity to provide the necessary continuity of operation when changing from the continuous process of conveying to the intermittent process of feeding the measured batches into the mixer, and not as bins for storing the material, since the storage of the large amounts of material to permit uninterrupted operation of the job as a whole, despite stoppage of the source of supply, is performed by the ground piles adjacent the conveyer, which in practice consists of many hundreds of cubic yards of sand and stone while the capacity of the storage hoppers 9-and 10 would be only a yard or two.

By this method of conveying, the storage hoppers can be reduced to a capacity which is less than the amount of material contained in the screen, elevator and conveyer combined and therefore since the height of a machine will be proportional to the capacity of this hopper, it will be seen that this is the reason a structure of a height not to exceed that permitting its passing under tunnels, trolley wires, etc, can be used. Concrete aggregate usually comprises diifering ingredients composed of particles of considerably differing size, such as sand and gravel or stone. The usual size of the particles of sand is such as would pass of the particles of each aggregate ingredient.

By my improved method of conveying, a considerable economy of structure is procured inasmuch as the conveying means may be operated and fed continuously, and also, my improved method eliminates the duplication of structure involved in the provision of two conveyers, and a further economy in this respect is effected by the fact that the mixture of the sand and gravel will occupy a bulk considerably less than the sum of their bulks when separated, due to the disposition of the sand into the interstices of the mass of gravel. Thus a relatively small size of the single conveyer may be had. This economy of structure permits a plant of suitable capacity to be kept within the weight limit necessary for portability.

What is claimed is:

The method of conveying, proportioning and feeding the ingredients of aggregate material, said method consisting in depositing upon a common primary conveyer from storage piles of said ingredients, roughly proportionate quantities of said ingredients, conveying and elevating said ingredients, separating said ingredients from each other, temporarily separately accumulating each of said ingredients and finally feeding from said accumulations exact proportional quantities of the said ingredients deposited upon said primary conveyer. v

In testimony that I claim the foregoing I have hereunto set my hand at Milwaukee, in the county of Milwaukee and State of Wisconsin, in the presence of twowitnesses.

mice 0. STAMP Witnesses:

FRANK L. RATOLIFFE, MAY .DOWNEY.