US3767158A

US3767158A - Concrete form construction

Info

Publication number: US3767158A
Application number: US00128951A
Authority: US
Inventors: G Mikus
Original assignee: FLEXICORE CO
Current assignee: FLEXICORE CO; FLEXICORE CO INC US
Priority date: 1971-03-29
Filing date: 1971-03-29
Publication date: 1973-10-23
Anticipated expiration: 1990-10-23

Abstract

A concrete from of the type comprising abutting, coplanar panels connected together in edge-to-edge abutting relation to form inner and outer from walls for the pouring of concrete therebetween, the panels being detachably connected together by pivotal latch arms and pins on adjacent panel ends and plural tie rods extending between the inner and outer panels at the junctures of pairs of side-by-side panels. The latch arms and pins are carried on metal straps secured to the outside faces of the panels, the straps being recessed at the panel edges to lie flush with the inner faces of the panels where the tie rods are carried. The tie rods are circular in cross-section and are carried by the recessed strap to break off inside the concrete wall by a single twist at their ends.

Description

United States Patent [1 1 Mikus CONCRETE FORM CONSTRUCTION Glenn H. Mikus, St. Louis, Mo.

[73] Assignee: The fileir icore Co., 111316551105,"

221 Filed: Mar. 29, 1971 211 App]. No.: 128,951

[75] Inventor:

[52] US. Cl 249/192, 249/40, 249/148, 249/190, 249/213 [51] Int. EQ4g 9/QQ Primary ExaminerJ. Spencer Overholser Assistant ExaminerDeWalden W. Jones Attorney-Stanley N. Garber 57 ABSTRACT A concrete from of the type comprising abutting, coplanar panels connected together in edge-to-edge abutting relation to form inner and outer from walls for the pouring of concrete therebetween, the panels being detachably connected together by pivotal latch arms and pins on adjacent panel ends and plural tie rods extending between the inner and outer panels at the junctures of pairs of side-by-side panels. The latch arms and pins are carried on metal straps secured to the outside faces of the panels, the straps being recessed at the panel edges to lie flush with the inner faces of the panels where the tie rods are carried. The tie rods are circular in cross-section and are carried by the recessed strap to break off inside the concrete wall by a single twist at their ends.

6 Claims, 5 Drawing Figures Patented Oct. 23,1973

2 Sheets-Sheet i 1 CONCRETE FORM CONSTRUCTION BACKGROUND OF THE INVENTION This invention pertains to concrete forms, and more particularly to an improved knock-down'type form for use in the pouring of concrete walls and building foundations.

Certain prior art concrete forms exemplified in US. Pat. Nos. 2,776,464 and 2,825,956 have gained wide acceptance and use in the construction industry, due primarily to the speed with which they can be erected for use and dismantled for either storage or use on another project. Typical of the tie rods or bars used in such forms are those illustrated in US. Pat. No. 2,290,371. These forms generally consist of plural, detachably coupled, rectangular panels in coplanar abutting edge-to-edge relationship defining an outer form wall and a similar plurality of panels defining an inner form wall, the inner and outer form walls beingspaced in parallel planes by the thickness of the concrete wall to be poured. The panels are detachably joined in endto-end abutting relationshipby pivotal levers or latch arms and latch pins carriedat the adjacent ends of the panels. The latch arms and pins are secured to elongate metal straps in turn secured to the outer face of each panel, the panels having notches at their edges under the straps and the straps being slotted to receive the head of the aforementioned tie rods or bars, thereby, upon pivoting of the latch arms over the head of the tie bars and latch pins, joining the side-by-side and inner and outer panels together to provide a relatively rigid form construction for the concrete.

While the prior art forms have gained wide acceptance and use over the past several years,'there are certain problems and disadvantages associated with the use of such forms. For example, the notches in the edges of the panels under the straps fill with concrete which, when set, tends to lock the forms to the concrete wall, rendering it difficult to remove the forms from the completed wall. In addition, the concrete in the panel notches either adhers to the finished wall forming protruberances on the wall which must be subsequently removed, or breaks loose from the wall and remains in the notches in the panel requiring cleaning of the panels before they can be used again. Additionally, the tie rods of the prior'art forms are captivated and held against rotation not only by the notched straps but also by the latch arms. Since the latch is designed to securely retain the tie rod against rotation, considerable force is required to close the latch over the rod and subsequently open the latch for removal of the panels. This frequently requires one or more blows from a hammer to accomplish, tending to slow down the operation and rapidly deteriorating the forms. In addition, since the tie rods are held against rotation by the latch arms they must first be broken by twisting at the latch to permit removal of the panels and, if a smooth wall is desired, e.g., the interior wall of a basement, they must be again broken slightly inside the wall by twisting after removal of the panels.

SUMMARY OF THE INVENTION Accordingly, among the several objects of the present invention may be noted the provision of a concrete form having flat, uninterrupted inner faces for producing a smooth concrete wall thereby eliminating the necessity of manually chipping plural mounds of concrete from the face of the completed wall; the provision of such a form which facilitates removal of the form from the completed wall and eliminates removal of concrete from the form prior to its subsequent use; the provision of a concrete form as above described which facilitates latching and unlatching of adjacent side-by-side forms to decrease the time and labor necessary to erect and dismantle such forms; the provision of such a form employing a unique tie bar and tie bar retaining mechanism permitting the ends of the tie bar to be broken off inside the completed wall by a single twist of the tie bar end, thereby facilitating removal of the forms; the provision of a concrete form which may be used interchangeably with existing forms and for either the inner or outer form walls; and the provision of such a form which is characterized by simplicity of construction, low cost and ease of operation and use.

In general, a concrete form assembly constructed in accordance with the present invention is comprised of a'plurality of detachably connected panels in edge-toedge coplanar abutting relationship defining a first form wall and a similar plurality of panels spaced laterally from the first panels defining a second form wall, with plural tie bars spanning the first and second walls at the juncture of coplanar panels in the first and second walls. Each panel is generally rectangular in shape having a recess opening into its abutting end edge for receiving a tie rod. Retaining means are provided entending in a common plane with the inner face of the panel from the end of the recess to the end edge of the panel for holding the tie rod against lateral movement with respect to the panel. Latch means are provided on the outer face of the panel for receiving the end of the tie rod and a latch surface on an adjacent panel to securely hold the panels in edge-to-edge abutting relationship.

Other objects and features will be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a concrete form assembly of this invention:

FIG. 2 is an elevation of a portion of the assembly of FIG. 1.;

FIG. 3 is a section taken on line 3-3 of FIG.2.;

FIG. 4 is a section taken on line 4-4 of FIG. 2.;

FIG. 5 is an isolated view ofa tie bar of this invention.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings:

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, and particularly to FIG. 1, the present concrete form'assembly is indicated generally at 10 as comprising a first or inner form wall 12 and a second or outer form 14. Each of the form walls 12 and 14 comprises plural, adjacent edge-

toedge abutting panels

16A, 16B and 16C, 16D. Each panel 16 is of generally rectangular configuration, is of a height approximately the height of the concrete wall to be built, and is one of a number of standard lengths to form concrete walls of various lengths. Panels 16 are illustrated as formed of heavy sheet plywood, although other materials, with or without reinforcing upright beams, may-also be used. The panels 16 are notched providing recesses 18 at their abutting side edges 20 for the passage of a tie rod or bar 22 between the inner and outer form walls 12 and 14, as will be more fully described hereinafter. Metal straps 24 are secured to the outer faces of each panel 16 by threaded bolts 26, or the like, the latter being countersunk so as to lie flush with the inner faces of the panels as shown in FIG. 3. Pivotal latch arms 28 are carried at one edge of each panel 16 for captivating tie bars 22 and locking adjacent panels in edgeto-edge abutting relationship, as also will be more fully explained hereinafter.

As illustrated, plural straps 24 and latching mechanisms 28 may be provided at spaced vertical intervals along the outer face of the panels depending on the height of the panels and the resultant concrete walls to be built.

In general, the assembly 10, comprised of laterally spaced inner form wall 12 and outer form wall 14, is erected at the site where a concrete wall is to be built and is adapted to receive the concrete between the inner faces of the inner and outer form walls. Once the concrete has hardened or set, the forms are removed and may again be used for another wall. Clearly, assembly must be sturdy and rigid to adequately support the concrete until set. For this purpose, the latch mechanisms 28 are provided to securely, but detachably, hold adjacent panels 16 in coplanar edge-to-edge abutting relationship, while the tie bars 22 hold the inner and outer form walls 12 and 14 in laterally spaced, parallel planes. It will be understood that it is highly desirable to produce a smooth finish on the completed concrete Wall while also reducing costs and labor in erecting and dismantling the form assembly.

As best illustrated in FIG. 24, the present form accomplishes the above objectives by providing an uninterrupted, flush inner form face and an improved tie bar and latching construction. More specifically, the elongate metal strap 24 is secured to and extends along the outer face of panel 16 with the exception of the edge notched area 18. The notch or recess 18 extends completely through the panel from its outer to its inner face and is substantially the same width as the width of metal strap 24. Notches 18 extend inwardly from both end edges 20 of the panel 16 and, as set forth above, receive the ends of tie bars 22. The ends 30 of the metal strap 24 are of L-shape in cross-section to conform to the shape of the notch 18 and close the recess at the inner face of the panel. That is, end portions 30 are provided with a first lateral extent 32 extending integrally with strap 24 from the outer face of panel 16 to the inner face of the panel, and a second longitudinal extend 34 extending flush with the inner face of the panel from the inner end of portion 32 to the edge 20 of the panel. A notch 36, having both a horizontal and a vertical reach, is provided in strap portion 34 for receiving tie bar 22.

As set forth above, strap 24 is secured to panel 16 by a plurality of bolts 26 as shown in FIG. 1. However, at the ends of panel 16 the bolt heads, designated 38, are spaced from the strap 24 for pivotal attachment of the latch arm 28 on one end of the panel and for providing a latch pin at the other panel end. Thus, latch arm 28 is pivotally carried by bolt 38 by an elongate opening 40 for pivotal movement into and out of locking engagement with bolt 38 on an adjacent panel, the latter being received by a slot 42 near the end of the latch. The latch arm is also provided with a pair of smaller slots 44 for receiving the end ofa tie bar 22. As shown in FIG. 2, the opening to slot 36 in strap portion 34 is rounded, as at 46, to permit lateral removal of the tie bar if necessary, for example, to install a window frame before pouring the concrete.

Referring now to FIG. 5, the tie bar 22 comprises an elongate metal bar having a generally circular crosssection throughout its length. Flattened pairs of ears 48 are formed near the center of the bar for holding the bar against rotation in the wall after the concrete has set. The cars 48 are provided only at the longitudinal edges of the bar to preserve a maximum cross-sectional area at the axis of the bar, hence minimizing the weakening effect of the ears. A shoulder 50 and a shoulder or head 52 are formed in each end of the bar outwardly of ears 48. The bar between portions 50 and 52 is received in slot 36 in strap end 34, with portions 50 and 52 retaining the bar against lateral movement with respect to the panel. Similar pairs of shoulders 54 and heads 56 are formed outwardly of head 52 for captivation of the bar by notch 44 of latch arm 28. As shown in FIG 2, heads 56 of bar 22 are rectangular providing flat surfaces for gripping with a wrench (not shown) to twist the bar and snap it at score lines 58 slightly inside the faces of the concrete wall.

Operation is as follows:

To assemble the form walls 12 and 14, the panels 16 in each wall are aligned in edge-to-edge coplanar abutting relationship and the tie bars are positioned such that the bar portions between shoulders 50 and heads 52 are in slots 36 of strap portions 34. This is accomplished by separating the panels sufficiently to insert the tie bars in the open mouth of the slots 36 between the abutting edges of adjacent panels. It should be pointed out that since the slotted strap portions 34 are provided at both end edges of each panel and the latch arms 28 are each provided with two bar receiving slots 44, the panels may be used universally for either the inner or outer form wall.

After positioning the tie bars 22 in slots 36, thereby securing together the inner and outer form walls 12 and 14, the latch arms 28 are pivoted downwardly over both the tie bar ends between shoulders 54 and heads 56 and the latch pin provided by bolt 38, thereby securely locking together adjacent coplanar panels in each form wall. The elongate opening 40 and knife edge lower surface of latch arms 28 facilitates this latching movement, and since the tie bars 22 are held laterally by bar portions 50 and 52, notches 44 always align with the bar between

bar portions

54 and 56.

After assembly, the concrete is poured between the inner and outer form walls and allowed to harden. The form walls are then removed by simply twisting the heads 56 of the tie bars to cause them to snap at score lines 58 slightly inside the faces of the completed concrete wall, followed by raising latch arms 28 off of latch pins 38 and tie bars 22. The panels may then be removed for storage or reuse.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results obtained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in 8. limiting sense.

I claim:

1. A concrete form comprising a panel of generally rectangular configuration having top and bottom edges and first and second side edges, a cut-out notch in at least one of said side edges between said top and bottom edges, said notch extending inwardly from said side edge from the outer face of said panel to its inner face, means adapted to receive and hold a tie bar against lateral movement with respect to said panel, said means extending flush with the inner face of said panel in said notch from the inner end of said notch to the side edge of said panel, and latch means on the outer panel face adjacent said side edge near said tie bar holding means for latching said panel to a similar, abutting panel.

2. A concrete form as set forth in claim 1 wherein said notch and tie bar holding means are provided at both said side edges.

3. A concrete form as set forth in claim 1 wherein said tie bar holding means comprises an elongate metal strap.

4. A concrete form as set forth in claim 3 wherein strap comprises a first portion extending along and secured to the outer face of said panel, a second portion integral with said first portion extending in said notch from the outer face of the panel to its inner face, and a third portion integral with said second portion extending in said notch flush with the inner face of said panel from said second portion to the side edge of said panel.

5. A concrete form as set forth in claim 4 further comprising a slot in said third strap portion for receiving said tie bar.

6. A concrete form as set forth in claim 1 wherein said latch means comprises a latch arm pivotally carried on the outer face of said panel for pivotal movement past the side edge of said panel, said arm having first and second slots therein extending from one edge, said slots respectively engaging said tie bar and a latch pin on an adjacent panel upon pivoting of said arm.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORECTION Patent: No. 3,767,158J Dated October 23, 1973 Inventor(s) G'lenn H. Mikus It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

On the title sheet, delete "[73] Assignee: The Flexicore Co.,

Inc. Dayton, Ohio".

Signed and sealed this 19th day of March 1974.

(SEAL) Attest:

EDWARD M. FLETCHER,JR. c. MARSHALL DANN Attesting Officer I Commissioner of Patents =oRM Po-wso (10-59)