US2841013A - Mortar batching device - Google Patents

Description

H. A. GADSDEN MORTAR BATCHING DEVICE July 1, 1958 Filed May 4, 1955 United States Patent C) MORTAR BATCHING DEVICE Harold A. Gadsden, Washington, D. C.

Application May 4, 1955, Serial No. 505,953 3 Claims. or. 73429 My invention relates to the proper proportioning of materials, such as those used in mortar and concrete mixes for construction work, and for other purposes.

It is a well known fact that lack of a specific amount of cementitious material to a specified amount of sand or other aggregate fails to produce the requisite and expected strength of the structure of which the masonry is a part. It is also well known that excessive amounts of sand in proportion to the cementitious material produces a motar which is subject to early erosion by the weather, such as rain and frost action. Likewise, a mortar with excess amounts of certain cementitious materials, too rich, lacks the requisite strength and wearing qualities. Since the cementitious material is the most expensive item'of the mortar, for reasons of economy, it is desirable to insure that excessive amounts of this material not be used. It is a further well known fact that failure to use the requisite amount of mortar not only produces a structure lacking in the expected strength, but promotes leaks which cause early interior and exterior deterioration of the structure of which the masonry is a part. All of which defects add to the cost of maintenance, reduce the utility of the structure as well as producing a lack of the expected safety factor of the structure. Economy of upkeep, prevention of slum conditions and safety require that not only must the specified formula be adhered to, but also that the mortar specified be correctly used. This will insure that each interstice of the masonry be filled with mortar.

The ordinary means available for accurately proportioning aggregates and cementitious materials for mortars and supplying them to a mixing unit (mechanical mixer or mortar box, for hand mixing) and assuring the materials use have not heretofore been equal to the problem set forth, chiefly because sand, the principal aggregate, in general is supplied to the mixing unit by the crude and extremely inaccurate method of so many shovelfuls to a pre-determined volume, or weight, of cementitious materials. The only clue as to the quality of the mortar is the laborers or masons judgment as to the mortars plasticity. Plasticity is largely affected by the fineness and clay content of the'sand, excessive fineness and clay content nullifies the masons judgment as to quality. The other method sometimes used is a volumetric measuring device such as a cubic foot box when the measurement of sand is required. Neither method allows for the varying volumes of sand or other aggregate caused by varying moisture content. There has not been any accurate method of assuring that the mortar has been correctly used.

The purpose of the present invention is to insure successive batches of mortar uniformly mixed by the prescribed formula of cementitious materials and sand or other aggregate, and, to insure that the specified amounts of correctly mixed mortar are used in the masonry, giving maximum uniformity of strength and weathering quality and reducing leakage, while at the same time preventing absolutely any interference in the way of ignorance on the part of labor or carelessness on the part of engineers or contractors to prevent the rigid adherence to the specified formula or methods. To this end my invention utilizes the angle of repose factor of the aggregate (sand) or other material to be measured. This angle of repose factor compensates for the added bulking of damp sand as compared to the same volume of dry sand. Likewise, the weight method of measuring aggregate (sand) is not as accurate as the angle of repose method because the volume and weight are affected by the moisture content of the aggregate, which moisture content is a constantly changing factor.

The angle of repose principle of the invention works in the following manner: The container, or hopper, which can be adjusted to hold varying volumes, is set to hold the specified amounts of cementitious material and aggregate. After the cementitious material is put into the hopper, aggregate is added to its full capacity. If the aggregate lacks the normal moisture content, excess amounts will slide off to the original stock-pile. If the moisture content of the aggregate is excessive, the aggregate will pile, or crown, in the hopper, giving added bulk needed to maintain the net constant volume of aggregate.

After the hopper is filled to capacity, the operator releases it by pulling a handle, and as the hopper turns to be dumped into the mixing unit the batch is tallied. A registering device installed in the unit, accessible only to the owner or his representative, gives a permanent and accurate record of the amount of mortar mixed. Since a definite quantity of masonry requires a definite amount of mortar, by invention not only assists the owner in assuring quality workmanship; it also assists in keeping job records as to progress of the work.

The accompanying drawings, one sheet, represent one means of carrying out my invention. Figure 1 shows the front view; Figure 2 shows an end view; solid lines show the hopper in position to receive its maximum capacity; the dotted lines showing it in position to receive its minimum capacity. Figures 3 and 4 are enlarged views respectively showing a part section and details of the control mechanism. The invention consists of a hopper I mounted on a shaft 2 which is fitted with housed bearings at either end, all of which is mounted on a frame 3. 4 is a circular disc firmly attached to 1 and 2 with notches so located as to coincide with the graduated capacities of the hopper 1. 7 is a cowling, or cover, which fits over 4 with an opening that can be adjusted to the desired and graduated notch 8 and secured by means of a thumb-screw 10 which fits into 9. The end of lever 5, one end hinged at 6 holds the hopper 1 in a loading position. When the hopper is filled to capacity, the operator pulls 5. This releases the hopper which begins turning toward the mixing unit. At the mid-point of the turning motion of the hopper, and while loaded, the batch is tallied and registered. 11 is a handle to facilitate emptying the hopper and to prevent the stalls ing of a mechanical mixer by the sudden dumping of the batch.

While my invention is basically designed for measuring ingredients of masonry mortars and concrete where central batching plants are not available, it is readily apparent that the device can be readily adapted for the fast and accurate measurements of bulk quantities such as grains, etc.

I claim:

1. A mortar batching device comprising a stand, a hopper comprising a container having one side thereof open, forming a month, said hopper being pivotally mounted on the stand, locking means having a plurality of engageable portions fixedly mounted on said hopper, a lever pivotally mounted on the stand and having an Patented July], 1953- end: portion engageable. with a, preselected portion of said locking means, the engagement of the lever and locking means determining the angl of repose of said hopper whereby the cementitious to aggregate ratio of mortar to, be measured in the hopper can be predetermined regardlessof the moisture content ofthe sand.

2. A mortar batching device according to claim 1 in: clnding a lip on the hopper extending normally to the mouth of thehopper.

3. In a mortar batching device as claimed in claim 1 wherein the locking means comprise an arcuate disc fixed to the end of the hopper and spaced notches in the periphery thereof, an adjustable guard having a single notch overlaying the periphery of said disc, whereby the lever may engage only one notch of the disc for each adjustable position of the guard,

References Cited in the file of this patent UNITED STATES PATENTS

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