US3770248A

US3770248A - Vibratory concrete applicator

Info

Publication number: US3770248A
Application number: US00149954A
Authority: US
Inventors: S Cahoon; C Steelman; L Welch
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-06-04
Filing date: 1971-06-04
Publication date: 1973-11-06
Anticipated expiration: 1990-11-06

Abstract

A tool for applying low slump, semi-plastic concrete to a formed supportive matrix to create thin shelled ferro-concrete element. The tool defines a reservoir-like chamber having at least one plunger of some areal extent, reciprocally movable substantially perpendicularly to the output orifice and the motion of concrete outwardly from the orifice and about the supportative matrix upon reciprocation. The plunger is moved by an electro-mechanical powering device. An external source supplies concrete under pressure to the reservoir. Species having variously shaped orifices are disclosed.

Description

United States Patent 11 1 Cahoon et al.

[ VIBRATORY CONCRETE APPLICATOR [76] Inventors: Samuel L. Cahoon; Clifton V.

Steelman; Lawrence E. Welch, all of Connell, Wash. 99326 221 Filed: June4, 1971' 21 Appl. 110.; 149,954

[51] Int. Cl B0lf 11/00 [58] Field of Search 259/D1G. 42, 153,

259/D1G. 41, DlG. 43, 178, 179, 169, 170; 425/456 1 Nov. 6, 1973 3,591,862 7/1971 Winston 259/DIG. 41

Primary ExaminerRobert W. Jenkins Attorney--Keith S. Bergman [57] ABSTRACT A tool for applying low slump, semi-plastic concrete to I a formed supportive matrix to create thin shelled ferroconcrete element. The tool defines a reservoir-like chamber having at least one plunger of some areal extent, reciprocally movable substantially perpendicularly to the output orifice and the motion of concrete outwardly from the orifice and about the supportative matrix upon reciprocation. The plunger is moved by an electro-mechanical powering device. An external source supplies concrete under pressure to thereservoir. Species having variously shaped orifices are disclosed.

3 Claims, 8 Drawing Figures [56] References Cited UNITED STATES PATENTS 2,185,540 l/1940 Cady 259/D1G. 42 2,225,015 12/1940 Le Belle... 425/456 2,376,221 5/1945 Baker 259/DIG 42 2,470,068 5/ 1949 Contenson 425/456 FIGURE 3 PATENIEDRUY 6 ma 3770.248

SHEET 10F 2 FIGURE 1 SAMUEL L. CAHOON, CLIFTON v. STEELMAN INVENTORS 8: LAWRENCE E. WE C PATENIEUNuv 6 m5 3770.248

SHEET 2 OF 2 FIGURE 6 FIGURE 3 FIGURE 8 SAMUEL L. CAHOON, CLIFTON v. STEELMAN INVENTORS- & LAWRENCE E. WELCH" VIBRATORY CONCRETE APPLICATOR BACKGROUND OF INVENTION 2. Description of Prior Art Heretofore ferro-concrete has become a structural material of commerce, especially in the construction of thin-shelled structures such as boats, containers and the like. The term ferro-concrete includes various shell-like structures having a concrete matrix about a relatively large proportion of reinforcing element normally a particularly configured array of elongate metallic rods and reinforcing screens of various sorts. A ferro-concrete structure is distinguishable from ordinary reinforced concrete in its relatively thin, shell-like natrue; in its relatively larger proportion of smaller reinforcing elements; and by its creation without complete form containment generally without any form containment at all. Obviously the distinction between reinforced'concrete and ferro-concrete is one of degree and oftentimes the area about the common boundary is nebulous. I 1

Because of the nature of the ferro-concrete structure, the concrete matrix must be placed in a relatively dry, low slump condition and thereafter unified about the reinforcing elements and surfacefinished to accomplish the desired resultant structure. The supporting surface must be of sufficient areal extent and density to maintain the plastic concrete matrix in place prior to set and the concrete itself must be of a sufficiently dry nature that it will remain in position and not require confining supportiveforms. Herein lies the advantage of ferro-concrete in thin shell-like structures of relatively complex especially curvi-form-shape, but these requirements also give rise to problems of place m entp Heretofore various spray type methods of placing concrete on dense, reinforcement have become known such as in the placement gunite. These methods have not proven satisfactory with ferro-concrete, however, as the matrix is necessarily of a stiffer nature and carries larger aggregate than gunite. Similarly spray placement tends to form non-homogenous boundaries about particles and does not create so strong a structure as if the concrete matrix were consolidated and unified as a homogenous plastic mass. The practice heretofore in the ferro-concrete arts has generally been to place the concrete matrix by manual manipulation, that is, by placing the relatively dry, low slump concrete on one side of the formed reinforcing core and manipulating it with trowels or similar tools to force low slump concrete used in -ferro-cement structures under pressure from an external source, receive it into an internal reservoir and cause mechanical force, applied in the reservoir, to extrude the mass through a shaped orifice to unify and consolidate it about a supporting structure and finish' one surface of the resultant shell. The vibrating element in the tool reservoir lessens the viscosity of the plastic concrete and causes its consolidation.

Various vibratory tools have heretofore become known in the fluiddisbursing and concrete arts. In the fluid disbursing art these tools generally have effected the method of disbursement 'of pressurized fluid from a nozzle and have not consolidated or fluidized the material. The vibratory tools known in the concrete arts generally have sought to consolidate an ununified mass of concrete after placement; whereas the vibratory motion of the instant invention consolidates the material before placement and propagates its motion through the material during placement. The instant invention is distinguished from various vibratory conveyors in that the supporting structure itself does not vibrate and the primary purpose of vibration is to consolidate and fluidize rather than to convey concrete. The instant invention is distinguished from the spray type placement of concrete in that it maintains the concrete as a consolidated mass at all times prior to placement and places it in a consolidated, unified fashion, whereas the spray placement of concrete does not necessarily consolidate it and oftentimes injurs the character of the placed product by entrapping air, accelerating normal setting, differentiating different portions, and the like.

SUMMARY OF INVENTION My tool provides a rigid periphery defining a reservoir-like placement chamber communicating with input and disposition orifices. The structure defining the disposition orifice may be variously shaped to aid in configuring and finishing the surface of the ferroconcrete structure. Normally a handle will be provided to aid manual manipulation of the device or appropriate auxillary structures to communicate with mechanical manipulative means.

A mechanical activating means, such as the disclosed electro-mechanical vibrating device, is associated with the tool, preferably externally of the reservoir chamber, with an elongate shaft extending into the reservoir chamber for reciprocal linear motion substantially normal to the disposition orifice. This rod carries at least one agitator having some areal extent to transmit the energyof motion to the surrounding concrete mass. If desired, particularly shaped or plural agitating devices may be associated with a single disposition orifice or placement chamber. Electric power is furnished the tool from an external source to render it operative.

'In use the tool is maintained adjacent the medial supportive element at substantially the desired position of 'a final concrete matrix surface. In thiscondition, upon supply of pressurized concrete and activation of the electro-mechanical vibrator, concrete is lowered in viscosity, passed through the disposition orifice and about the supportive structure to there be unified and consolidated. The device may be moved over a surface to form a continuous concrete matrix.

-In providing such a tool it is:

A principal object of my invention to provide a reservoir type tool with one or more agitators reciprocally moving in a linear fashion within the reservoir chamber to aid relatively dry, low slump concrete therein to move through a placement orifice and consolidate about a medial supportive element to form ferroconcrete structures.

A further object of my invention to provide such a tool with a particularly shaped periphery defining the placement orifice so that this periphery may be manipulated to establish a finished surface on the ferroconcrete structure.

A still further object of my invention to provide a tool of the nature aforesaid that is of new and novel design, of rugged and durable nature, of simple and economic manufacture and one otherwise well adpated to the uses and purposes of which it is intended.

Other and further objects of my invention will appear from the following specification and accompanying drawings which form a part of this application. In carrying out the objects of my invention, however, it is to be remembered that its essential features are susceptible of change in design and structural'arrangement with only one preferred and practical embodiment being illustrated as required.

BRIEF DESCRIPTION OF DRAWINGS In the accompanying drawings which form a part of this application and wherein like numbers of reference refer to similar parts throughout:

FIG. 1 is an idealized orthographic cross sectional view of a typical tool of my invention showing its various parts, their configuratoin and relationship.

FIG. 2 is an orthographic surface view, partially cutaway, showng the operation of a tool similar to that of FIG. 1, supplied by an external source of electric power and an external'source of concrete.

FIG. 3 is an orthographic surface view of a species of my invention having a placement orifice adapted to finish convexly curved surfaces.

FIG. 4 is an isometric surface view of a species of my invention adpated to place concrete matrix in small areas that are difficult of access. 2

FIG. 5 is a specie of my invention having plural vibrators to place concrete matrix over relatively large flat areas.

FIG. 6 is a vertical, medial cutaway view of the device of FIG. 3.

FIG. 7 is a s'imilar'cutaway view of the device of FIG. 4.

FIG. 8 is a similar cutaway view of the device of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in more detail and particularly to that of FIG. 2, it will be seen that my invention comprises generally body 10 defining placement orifice 11 and structurally carrying concrete receiving means l2, handle means 13 and agitator.

body element may be formed as a unitary structure or with removable parts 18, as desired. The removable type structure often times is easier to form, care for, and clean. The body may provide housing 19 for agitator structure 14, if desired, and will provide bearing 20 for the agitator rod to allow a reciprocating, sliding motion of the rod relative the body structure.

The particular shape of reservoir chamber 15 is not critical to my invention but it has to be related in size to the placement orifice to be properly operative. The body element may be formed from any rigid material that is reasonalby durable in the environs of wet concrete, but we have found aluminum to be particularly useful for this purpose because of its light weight, relatively great strength, and ease of formability.

Placement orifice 11, defined by peripheral skirt 21 of body 15, may take various shapes but will provide a channel through which plastic concrete may exit from the reservoir chamber. The outermost surface 22 of skirt 21 will normally be a ruled surface with elements parallel with the particular direction of motion of of the tool in finishing a concrete surface to allow formation of the finished surface. This surface 22 may be planar or curvilinear as desired and its area] extent may be increased if a particularly fine finish be desired, all according to principals known in the concrete. finishing arts.

Concrete receiving structure 12 provides orifice 23 communicating by channel 16 to the reservoir chamber to form a course for inflow of plastic concrete. Normally the input orfice will be provided with some means, such as external threads 24, for communicating with an external concrete supply. As illustrated in FIG. 2, external threads 24 communicate with fixture 25 of supply hose 26 to provide a concrete channel from external supply source 27.

Manipulative means 13 comprise external handle structure 28, having gripping means 29, structurally carried by body 10 to aid in the manual manipulation of the tool. The handle structure may take various forms in various species of tool, and plural handles may be used, if necessary, as illustrated in FIG. 5.

Agitator means 14 comprise agitator 30 carried by elongate agitator rod 31 journaled in bearing 20 of the body structure to communicate with an activating means, in this instance electro-mechanical vibrator 32, to cause a cyclic linear motion communicated by the agitator rod to agitator 30. The electro-mechanical vibrator is structurally mounted on body 10 by some fastening means 33, preferably of a removable nature so that the element can be replaced if necessary. The normal electro-mechanial vibrator exerts linear force in only one direction so a mechanical bias such as spring 34 is interposed in the system to cause a positive reciprocating motion to the agitator relative body 10 or more precisely relative that portion of body 10 defining disbursement channel 17. The particular nature of the electro-mechanical vibrator'and its mounting are not critical to my invention and various other devices providing similar mechanical motion could be used so long as reciprocating linear motion is provided to the agitator rod. In experiment I have found that the vibrator preferably should provide about 7,200 strokes per minute. The length of the strokes is related to the shape of the agitator and sizes of the various elements as well as the nature of the concrete, but with normal concrete matrix used in present day ferro-concrete structures, and sizes substantially as illustrated in FIG. 1, a stroke of one-sixteenth of an inch has been found quite satisfactory, though the device is operative for a fairly wide range about this median.

Preferably agitator 30 is releasably connected to the agitator rod 31, such as byinternally threaded cap 35 structurally carried by the agitator and threadedly communicating with external threads 36'at the end of the agitator rod. The releasability is desirable for replacement of the element and cleaning.

The configuration of the agitator must be suchas to present a cross-section of some areal extent perpendicular to the direction of motion of the agitator to most effectively transmit its force to the concrete mass thereabout. A disc-like shape most'efficiently fulfills this requirement and if the disc be concave facing the placement orifice and convex on the other side it may further aid in moving the concrete matrix. Thepositioning of the agitator should be such that it vibrates immediately inwardly of the placement orifice. With this structure, as the agitator vibrates its motion will be transmitted to, and to some extent through, the plastic concrete thereabout to lessen its viscosity, consolidate it into a dense homogeneous mass and aid its consolidation about and in the intrices between the supportative structure. If the agitator be concave-convex its motion will create a statistical mechanicl situation with greater force exerted on the surrounding mass when moving in the concave than in the convex direction to thusly tend to aid motion of the concrete out the placement orifice. The exact shape of the agitator does not appear to be critical so long as the general configuration is followed but its particular size, cycling and stroke length must all be considered relative the concrete matrix and tool configuration to determine proper parameters. All of these parameters are quite complex and must be individually determined emperically orby known engineering methods in a particular instance.

Electro-mechanical vibrator 32 is supplied power from an external electrical source 37.

Various species of my invention providing different sized and shaped reservoir chambers and placement orifices are illustrated in FIG. 3, et seq. The device of FIG. 3 is adapted to' finish a convexly curved surface by reason of the shape of surface 22a of its exit orifice. The device of FIG. 4 providesa relatively small placement orifice that is therefore by reason of its size and shape well adapted to service small areas of difficult accessability. The species of invention of FIG. 5 provides two agitator structures and two handles to place concrete matrix through a relatively large placement orifice upon a relatively large flat surface. All of the species differ only in the particular configuration of their parts, but operate in the same fashion as the generic form of invention described and illustrated in FIG. 1 and 2.

Having thusly described the structure of my invention its operation may now be understood.

Firstly a device is formed to a particular configuration such as that illustrated in FIG. 2. A ferrosupportive structure 38 is formed as well known in the ferro-concrete arts with a relatively large volume of support elements, relatively closely spaced and defining in general the shape of the finished concrete matrix to be established thereabout.

My tool then is supplied with relatively dry, lowslump concrete matrix 39 under sufficient pressure from source 27 to transport it and electro-mechanical vibrator 32 is activated to cause motion of agitator 30. As reservoir chamber fills with concrete matrix material agitator 30 moved in reciprocal linear fashion therein. This motion lessens theviscosity of the concrete, consolidates it into a homogeneous mass and array generates a net force in the direction of motion toward which the concave side of the agitator faces. This action plus the pressure from the concrete supply causes the material concrete in the reservoir chamber to pass through the placement orifice. The tool is positioned with the skirt at the approximate desired finished surface and concretewill be moved without the placement orifice to this surface.- The concrete will be forced within the intricacies of the ferro-supporting structure and unified thereabout by reason of plastic pressure and vibration. The tool then, as a surface is established therebeneath, is moved so that surface 22 of the placement orifice continuesto be coincident with the desired finished surface 40 of the particular ferroconcrete structure 21 and in this'fashion the ferroconcrete matrix will be placed and-the external finished surface of the structure established.

It is to be particularly noted that with use of my invention at all times the concrete matrix during placement will be a unitary whole without anyparticular entrapment of air or any action tending to create voids or nonhomogeneties. g

It should further be noted that the mechanical vibration established in the plastic concrete matrix will to some degree be transferred through it to aid in unifying the concrete about the ferrosupportive structure and in maintaining'an intimate, continuous matrix thereabout.

It is further to be noted-that the thickness of the concrete structure 41 may be determined to some degree by position and time of transit'of my tool over a particular area, the greater the time of delay the greater the thickness.

The foregoing descripton of myinvention is necessarily of a detailed nature so that a specific embodiment of it might be set forth as required, but it is to be understood that various modifications of detail, rearrangement and multiplication of parts may. be resorted to .without departing from its spirit, essence or scope.

I-Iavingthusly described my invention,what I desire to protect by Letters Patent, and

What I claim is: 1. A tool of the nature aforesaid for placing a concrete matrix about a formed ferro-supportive structure in the creation of ferro-concrete elements, comprising in combination:

a body defining an internal reservoir chambercommunicating with a concrete receiving structure and a placement orifice and having associated manipulative means; agitator means .operatably associated with the body including an agitator having some areal extent perpendicular to its direction of motionand comprising a disk-like shape with a concave surface facing the placement orifice and a convex surface facing obversely to the placement orifice to urge concrete matrix in the internal reservoir chamber toward the placement orifice, the said agitator carried on an agitator rod journaled for reciprocatingslideable motion in the internal reservoir chamber with the agitator in a medial position relative the placement orifice and adapted for motion normal thereto; and means of moving the agitator rod in a linear reciprocating fashion.

3,770,248 7 8 2. The invention of claim 1 wherein the means of 3. The invention of claim 1 having more than one agimoving the agitator rod comprise an electromechanical device producing lineal motion up to onefourth of an inch at a frequency of approximately 7,200 cycles per minute.

tator means operatively associated with a single internal reservoir chamber.

Claims

1. A tool of the nature aforesaid for placing a concrete matrix about a formed ferro-supportive structure in the creation of ferro-concrete elements, comprising in combination: a body defining an internal reservoir chamber communicating with a concrete receiving structure and a placement orifice and having associated manipulative means; agitator means operatably associated with the body including an agitator having some areal extent perpendicular to its direction of motion and comprising a disk-like shape with a concave surface facing the placement orifice and a convex surface facing obversely to the placement orifice to urge concrete matrix in the internal reservoir chamber toward the placement orifice, the said agitator carried on an agitator rod journaled for reciprocating slideable motion in the internal reservoir chamber with the agitator in a medial position relative the placement orifice and adapted for motion normal thereto; and means of moving the agitator rod in a linear reciprocating fashion.

2. The invention of claim 1 wherein the means of moving the agitator rod comprise an electro-mechanical device producing lineal motion up to one-fourth of an inch at a frequency of approximately 7,200 cycles per minute.

3. The invention of claim 1 having more than one agitator means operatively associated with a single internal reservoir chamber.