US3722164A

US3722164A - Spring wire spacer, especially for spacing reenforcing mesh from the form in the manufacture of concrete structures and the like

Info

Publication number: US3722164A
Application number: US00113976A
Authority: US
Inventors: H Schmidgall
Original assignee: Hawkeye Concrete Products Co
Current assignee: Hawkeye Concrete Products Co
Priority date: 1971-02-09
Filing date: 1971-02-09
Publication date: 1973-03-27
Anticipated expiration: 1990-03-27

Abstract

In the casting of concrete pipe, etc. the reenforcing mesh must be kept in spaced relation to the form during the introduction of the concrete. This invention pertains to a novel spring wire spacer attachable to and detachable from the mesh and having a projection engageable with the form to space the mesh properly.

Description

United States Patent 091 Schmidgall Filed: Feb. 9, 1971 Appl. No.: 113,976

U.S.C1.. ..52/684, 24/261 R, 52/652, 52/719 Int. Cl. ..E04c 5/16, E04h 12/00 Field of Search, ..52/652, 657 68 4, 685, 719, 52/699;24/261R [11] v 3,722,164 [4 1 Mar. 27, 1973 [56] References Cited UNITED STATES PATENTS 1,498,595 6/1924 Wedmore ..5 2/719 1,025,330 5/1912 Straus ..52/685 5 919,099 4/ 1909 Wedniore .52/685 1,189,297 7/1916 Schenthaler ..52/685 3,359,019 12/1967 Pinkney ..'..52/719 3,471,986 10/1969 Swenson ..52/652 Primary Exa miner -Henry c. Sutherland Attorney-Harold M.- Knoth' ABSTRACT In the casting of concrete pipe, etc. the reenforcing mesh must be kept in spaced relation to the form during the introduction of the concrete. This invention pertains to a novel spring wire spacer attachable to s Ciaims, 10 Drawing Figures PATEIHFUHARZYISYS 722,154

SHEET 10F 2 .T A 44m l\32 FIG. 5 FIG. 6

INVENTOR. H. H. SCHMIDGALL PATENTEDHARZYIHYES 722,154

SHEET 2 OF 2 8 FIG. 9

H. H. SCHMIDGALL I N VEN TOR.

SPRING WIRE SPACER, ESPECIALLY FOR SPACING REENFORCING MESH FROM THE FORM IN THE MANUFACTURE OF CONCRETE STRUCTURES AND THE LIKE BACKGROUND OF THE INVENTION The need for spacing in the above art is of course well recognized and several forms of clip-on spacers have been provided, mainly, however, with limited success. One of the best known spacers in the prior art is a member formed of strip steel having hooked ends to clip over or snap onto parallel rods of the reenforcing mesh or cage, and intermediate the hooked ends. is an integral outwardly projecting V serving to contact the form wall and thus to space the cage from the wall. See, for example, U.S. Pat. No. 3,471,986. The term cage, as used herein refers to the cylindrical type I mesh used in the casting of concrete pipe, but the problem occurs also in casting of other concrete shapes.

In one method of casting concrete pipe, a form is provided having inner and outer concentric form walls into which a single, double, etc. gage is interposed. Assuming a single concentric cage, this is spaced from both forms by some means, such as that suggested above. Normally, the cage will be equipped with, say, inner and outer spacers and the two forms, as a unit, will be slipped over the cage. One problem that occurs is that the spacers ore often dislodged as the form is applied, because the spacers cannot resist the axial forces during assembly. Also, if the spacers are made of strip metal, they present areas that interfere with the-free flow of concrete, thus causing the occurrence of voids. Further, when the form is stripped from the finished pipe, especially when the concrete is not fully 'set, the spacers may be displaced again, causing further defects in the pipe. I

In another system of manufacture, the packer head method is used, employing only an outer form within which a packer head rotates to operate centrifugallyon the concrete as the latter is introduced, thus packing the concrete through the mesh and against the single outer form. The spacers must resist not only the axial forces caused 'by the assembly of the form over the mesh but also the centrifugal and circumferential forces resulting from rotating of the packer head. If the spacers are not securely affixed to the mesh, they may become dislodged, and the mesh loses it concentricity,

or the spacers yield circumferentially and again the v mesh becomes improperly located.

A further system resorts to.cutting parts of the mesh and bending these parts outwardly to serve as spacers. Because the mesh rods are relatively heavy, as compared to known snap on spacers, sufiicient strength is achieved, but at the expense of a labor-consuming method. In some other instances, separate spacers of adequate strength may be preliminarily welded to the mesh, but this too is costly and laborious.

Where the above-noted strip-like snap-on spacers are used, several sizes must be used to accommodate SUMMARY OF THE INVENTION ment but quickly recovers its original form, and is quite inexpensive. It is preferably manufactured with specially designed bends, shapes and angles to accommodate rods of varying diameters, can be used inside or outside the mesh, vertically, horizontally and is virtually nondisplaceable during form assembly, introduction of the concrete and, in the packer head system, does not distort and therefore keeps the mesh concentrio with the form. Further, being made of relatively light-weight wire, it does .not present objectionably large areas to interfere with the free flow of concrete. As a further feature, because the spacing projection is a terminal portion of the coil or serpentine part, projections of various lengths may be easily provided by making the projection longer or shorter, as desired, before forming the serpentine portion. Other features will be brought out as the description proceeds.

DESCRIPTION OF THE DRAWINGS FIG. 3 is an elevation of the article as used in another position on the mesh.

FIG. 4 is an elevation of the article as used in another position on the mesh.

FIG. 5 is an elevation of the article as used in another position on the mesh.

. FIG. 6.is an elevation of. the article as used in another position of the mesh.

FIG. 7 is a perspective illustrating the characteristics of the article and the manner of mounting same on the mesh.

' FIG. 8 is an end view of the article, broken lines being used to illustrate the relative parts of the mesh.

FIG. 9 is a view at to FIG. 8.

FIG. 10 is a plan of FIG. 8.

DESCRIPTION OF A PREFERRED EMBODIMENT The invention is disclosed in relation to its use in a packer head system employing only an outer form wall 20 (FIG. 9) and a typical reenforcing mesh or cage 22 made up of horizontal rods 24 and vertical rods 26. Here, as elsewhere, as well as in the claims, such expressions as horizontal," vertical, front, rear, upper etc. are employed in the interests of brevity and clarity, because, as seen from the drawings, the article is extremely versatile and can be used in a multitude of positions. Likewise, it is not intended to exclude the applicability of the invention to meshes and/or cages of diagonal, etc. types.

Further, because of the illustration of the invention in a packer head system, primary concern is with spacing from the outer form wall 20, but it will be clear that similar spacing results may be accomplished where an in one inner form wall is used. Likewise, it is immaterial whether the mesh is single, double etc.

It should be observed at this point that a further feature of the invention is that it adapts itself to meshes in which the rods have different spacing, whether deliberate or as a result of errors in manufacture,

angle of approximately 90 (FIG. 8), but this angle may be modified manually in certain circumstances, or

. a special form of the element 30 may be created. There because the improvedspacer article may span a pair of adjacent parallel rods, one rod and a cross rod, etc.

The improved article is designated in its entirety as 30 and is a one-piece element of spring wire, preferably of the grade known commercially as Premier Grade. This wire is tough, resilient and retains its pre-shaped A form, but is capable of being over-stressed and even then performs satisfactorily.

A basic component of the element 30 is a serpentine or similarly configured part 32 (FIG. 7) including at least one spiral-like turn generated about an axis. In FIG. 7, a rod 24 has been shown as including an axis AA, which axis is duplicated in the forming process of the element. The spiral-like turn has a projection or spacer leg 34 directed away from the axis AA at one end portion of the turn and further has, at its opposite end portion, an extension in the form of an elongated lever arm 36 directed away from the axis AA generally in 9 oclock relation to the projection 34. That is to say, if one views FIG. 9, he will observe the relationship just described. This relationship is considered with the axis AA as the center or pivot from which the

portions

34 and 36 project radially.

In FIG. 8, the axis AA has been superimposed,

along with the centerline BB of a vertical mesh rod 26, it being clear that the element 30 is in its free state; i.e., it has not been assembled to the mesh.

Considering the serpentine part 32 more specifically it is seen that it includes a first bend or part-tum 38 and a second bend or part-tum 40. These are oppositely directed; that is, considering FIG. 7 as representing a pre-assembly stage as respects FIG. 1, the bend 38 goes over the rod 24 from above and in front, and the bend 40 goes under and upwardly in front of the rod 24 (or axis AA) and is coaxially spaced apart relative to the bend 38. The two bends 38 and 40 are interconnected by an intermediate portion or bight 42 that lies along but is displaced behind the rod 24 or axis AA. Because the

bends

38 and 40 engage the rod 24 respectively below and above, it follows that deflection of the lever arm 36 in the direction of the arrow C in FIG. 7 applies a downward force on the bend 38 and an upward force on the bend 40 so that the wrap-around of the rod 24 by the part 32 locks the element to the rod against rotation about an axis DD normal to the axis AA, whereby the rod-engaged bend 40 serves as a fulcrum for the lever arm 36, about which the lever arm may be stressed in bending about such fulcrum (dotted lines, FIG. 7) and the upper end of the lever arm may be locked to another rod; e.g. 26 in FIG. 1, 24 in FIGS. 2, 3, 4, 6 etc., depending upon the position of the element 30 on the mesh 22. To facilitate locking of the terminal end of the lever arm 36, said arm is provided with a hook-like portion 44, having the versatility of being able to lock over various of the rods. Further, because of the nature of the spring wire, the relationship of the arm 36 to the general axis of the part 32 may be distorted, as in the case of FIGS. 3 and 4; that is, the preferred relationship between 36 and 32 includes an still remains sufficient spring force to achieve the necessary locking effect.

Although the serpendne form of the part. 32 is not a simple helix or spiral, such helix or spiral could be used, but the specific form shown has certain advantages. In the present case, the intermediate portion or bight 42 is in the form of a V having

convergent legs

46 and 48 substantially coplanar with the bight and joined respectively to the

bends

40 and 38, the legs being related to each other at an angle of approximately (FIG. 10). This construction improves the wrap-around" effect of the serpentine part on the rod with which it is associated. Further, the manufacture is much easier and less expensive, because it is simpler to form bends than coils as such.

The junction of the lever arm 36 with the portion 42 at the bend 40.is also approximately-90, as is the junction of the portion or leg 48 at 38 with a straight leg portion 50 which leads to the spacing projection 34 via a bend 52, which is on the order of 8288, preferably 84. The purpose of the lessthan-90 bend just described is to compensate for intersecting rods of relatively different diameters and also to allow for differences in the position of the element as affected by whether it hooks simply over one rod (FIG. 4) or over two rods as at an intersection (FIG. 1).

It has been further found desirable that all radii be on the order of the cross-sectional dimension of the wire from which the element 30 is formed. Because of reasons of economy, the wire is round, but this does notexclude cross-sections of other forms. In the present case, the wire has a diameter of one-eighth inch.

In a preferred embodiment, the hook 44 has a special configuration. In this case, the hook includes a first straight portion 54 bent off at approximately 90 from the top of the lever arm 36 (FIG. 8) and a continuing straight terminal portion 56 bent off from the portion 54 at an angle in the order of 6070, preferably 67. This relationship keeps the hook open enough for easy installation and yet provides for an adequate lock to the engaged rod.

An important feature of the invention is that spacing is accomplished from the outside of the mesh 22; i.e., the side facing the form 20. Considering no'w FIG. 7 and observing that one is looking inwardly of the assembly, it will be seen that the

portions

50 and 40 are in front of the rod. Thus, the projection 34 is based on or abuts against the front" of the mesh. Likewise, the lever arm36 starts at 40 in front of the mesh and hooks behind a rod portion. The fulcrum at 40 includes a plurality of infinite axes about which the lever arm 36 is stressed, insuring that the lock-in of the hooked end 44is complete. As observed before, the element 30 may be used in a multiple of positions, inside and/or outside of the mesh, and the projection 34, being column-loaded is capable of resisting radial forces. Because of the lock-on principle, the projection 34 also resists circumferential forces and can, in any event, roll with the punch. I

Another feature of the invention is that, because the element can hook onto combinations of horizontalhorizontal or horizontal-vertical rods, inventory can be reduced by two-thirds, since one size can fit several meshes, and this is also true of the ability of the element to accommodate varying rod diameters.

I claim:

1. An article of the class described, comprising a one-piece element of spring wire having a basic component configured to provide first and second legs extending toward and joined together by a bight, said legs and bight lying generally in a common plane and each leg having an end portion remote from said-bight, said end portions lying generally on a line included in said plane and the bight lying to one side of said line, an elongated lever arm projecting in one direction away from and generally perpendicular to the plane and having a junction with the first leg portion, a relatively short third leg projecting away from the plane in the direction opposite to that of the lever arm and generally perpendicular to the plane and having a junction with the second leg end portion, said third leg having an end portion, a spacer leg spaced from the plane at the side thereof from which the third leg'projects and having a generally right angular junction with the third leg end portion and extending from said third leg end portion in substantially right-angle relation to the aforesaid line and lying on that side of the line opposite to that at which the aforesaid bight lies.

2. The invention defined in claim 1, in which the end of the lever arm remote from the plane is formed as a hook.

3. The invention defined in claim 1, in which the bight is in the form of a V and the first and second legs converge toward the V at an angle on the order of 4. The invention defined in claim 1, in which the spacer leg is related to the third leg at an angle on the order of between 82 and 88.

5. The invention defined in claim 1, in which the relationship between the lever arm and the spacer leg is substantially 9 oclock and viewed endwise along a line lying in said plane and extending between the respective junctions between the first leg and lever arm

Claims

1. An article of the class described, comprising a one-piece element of spring wire having a basic component configured to provide first and second legs extending toward and joined together by a bight, said legs and bight lying generally in a common plane and each leg having an end portion remote from said bight, said end portions lying generally on a line included in said plane and the bight lying to one side of said line, an elongated lever arm projecting in one direction away from and generally perpendicular to the plane and having a junction with the first leg portion, a relatively short third leg projecting away from the plane in the direction opposite to that of the lever arm and generally perpendicular to the plane and having a junction with the second leg end portion, said third leg having an end portion, a spacer leg spaced from the plane at the side thereof from which the third leg projects and having a generally right angular junction with the third leg end portion and extending from said third leg end portion in substantially ''''right-angle'''' relation to the aforesaid line and lying on that side of the line opposite to that at which the aforesaid bight lies.

3. The invention defined in claim 1, in which the bight is in the form of a V and the first and second legs converge toward the V at an angle on the order of 90*.

4. The invention defined in claim 1, in which the spacer leg is related to the third leg at an angle on the order of between 82* and 88*.

5. The invention defined in claim 1, in which the relationship between the lever arm and the spacer leg is substantially ''''9 o''clock'''' and viewed endwise along a line lying in said plane and extending between the respective junctions between the first leg and lever arm and the second and third legs.