US3861096A

US3861096A - Spaced bar for concrete reinforcing steel mats

Info

Publication number: US3861096A
Application number: US326684A
Authority: US
Inventors: Harold R Emmons
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-01-26
Filing date: 1973-01-26
Publication date: 1975-01-21
Anticipated expiration: 1992-01-21

Abstract

A spacer bar for maintaining a reinforcing steel mat a predetermined fixed distance from the inside surface of a first wall form of a pair of spaced first and second wall forms while concrete is poured around it. The spacer bar is designed to be inserted through a hole in the first wall form and has a hook portion engaging a rib on the outside surface of the first wall to retain the bar in position. Two embodiments are illustrated for use where there are to be one or two steel mats, respectively. After the concrete is poured, a fracturable portion intermediate the ends of the spacer bar is broken and the exposed ends of the bar removed.

Description

United States Patent Emmons Jan. 21, 1975 4] SPACED BAR FOR CONCRETE 3,385,555 5/1968 Williams 249/192 OR G STEEL MATS R16,793 11/1927 Smith 249/216 X [76] Inventor: Harold R. Emmons, 501 Oak St., FOREIGN PATENTS 0R APPLICATIONS Lebanon, Ohio 45036 291,838 6/1928 Great Britain t. 249/93 [22] Filed: Jan. 26, 1973 Prtmary Examiner-Francis S. Husar 1 1 pp 326,684 Assistant ExaminerJohn S. Brown Attorney, Agent, or FirmDybvig & Dybvig [52] US. Cl 52/98, 52/677, 52/699,

249/91, 249/213 [57] ABSTRACT [51] Int. Cl E04b 1/00 A spacer bar for maintaining a reinforcing Steel mat a [58] held of Search 52/98, 699; 249/ predetermined fixed distance from the inside surface 249/41 of a first wall form of a pair of spaced first and second 249/93 wall forms while concrete is poured around it. The spacer bar is designed to be inserted through a hole in [56] defences Cted the first wall form and has a hook portion engaging a UNlTED STATES PATENTS rib on the outside surface of the first wall to retain the 934,433 9/1909 Fellows 52/691 bar in Position TWO embodiments are illustrated for 946,987 1/1910 Schade 52/699 X use where there are to be one or two steel mats, re- 1,183,128 5/1916 Sheldon 249/93 spectively. After the concrete is poured, a fracturable 1,924,724 3/1933 52/699 X portion intermediate the ends of the spacer bar is bro- 2,095,714 10/1937 P1naud 249/214 ken and the exposed ends of the removed 2,501,412 3/1950 Schaefer 249/213 UX 2,595,123 4/1952 Callan 1 249/38 X 8 Claims, 6 Drawing Figures SPACED BAR FOR CONCRETE REINFORCING STEEL MATS BACKGROUND OF THE INVENTION This invention relates to a spacer bar for maintaining a reinforcing mat in place between a pair of spaced first and second wall forms while concrete or the like is poured and permitted to set around it.

In general construction practice, it is frequently necessary that reinforcing steel mats be placed within concrete forms prior to pouring the concrete therein. For structural and appearance reasons, it is necessary that the steel mats be accurately positioned at a desired distance from the concrete wall form and the finished surface of the resulting concrete wall.

Accordingly, an object of this invention is to produce a low cost spacer bar which can be installed on a wall form from one side of the wall form by an unassisted construction worker to enable a steel mat which is secured to the spacer bar to be positioned at a fixed distance from the inside surface of the wall form.

Another object of this invention is to produce a spacer bar of the above type which is adaptable for use in installing two steel mats within a pair of spaced wall forms whether they be parallel, curved, or converging as in a double-faced battered wall.

Another object of this invention is to produce a spacer bar of the above type which may be installed on existing wall forms without the necessity of boring holes therein or damaging the surfaces of the wall forms which are sometimes plastic coated to preserve the wood underneath.

Some representative prior art techniques for positioning steel mats within concrete forms are shown in the following U.S. Pat. Nos.:

1,014,630 Morrill Jan. 9, 1912 2,114,590 Colt Apr. 19, 1938 2,412,307 Tatsch Dec. 10, 1946 2,704,390 I-Iummel Mar. 22, 1955 3,197,171 Michalak July 27, 1965 3,263,956 Hawkins Aug. 2, 1966.

SUMMARY OF THE INVENTION This invention relates to a spacer bar for maintaining a reinforcing means like a steel mat at a predetermined fixed distance from the inside surface of a first wall form of a pair of spaced first and second wall forms. The first wall form has slots therein and reinforcing ribs on the outside surface thereof to which the spacer bar is secured. The spacer bar comprises a rod member having first and second end portions with a fracturable, weakened portion located between the end portions, and spring means positioned on the rod member be tween the end portions. The first end portion has a reverse bend or hook thereon, and the second end portion has a flange member secured thereto to facilitate the securing of the steel mat thereto. The reverse bend of the spacer bar is dimensioned to enable it to pass through one of said slots and engage one of the ribs to thereby enable an unassisted worker to install the spacer bar from the inside surface of the first wall form. The spring means is used to resiliently urge the hook of the spacer bar against one of the ribs on the wall form to prevent rotation of the flange member and to maintain it the fixed distance away from the inside surface of the first wall form. A second embodiment of the spacer bar, generally similar to the embodiment just described, is used to maintain first and second reinforcing mats at two fixed distances from the inside surfaces of the first form.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a portion of a first concrete wall form to which one embodiment of spacer bars of this invention are connected, and showing the general relationship of the first wall form to a second concrete wall form.

FIG. 2 is an end view in elevation, taken along the line 2-2 of FIG. 1.

FIG. 3 is an enlarged cross sectional view. taken along the line 33 of FIG. 2, to show additional details of the spacer bar shown in FIG. 2.

FIG. 4 is an end view in elevation similar to FIG. 2 except that it shows another embodiment of a spacer bar of this invention.

FIG. 5 is a perspective view of the spacer bar shown in FIG. 4.

FIG. 6 is a perspective view of the spacer bar shown in FIGS. 2 and 3.

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is a perspective view of a portion of a composite wall form for concrete which includes a first wall form and a second wall form designated generally as 10 and 12, respectively. The first wall form 10 is made up of

prefabricated panel units

14 and 16 arranged in edge-to-edge abutting relationship as shown. Each panel unit like 14 and 16 has vertically positioned

metal reinforcing ribs

18 and 20 located on opposed sides thereof. These reinforcing

ribs

18 and 20 have suitably aligned slots therein to enable two adjacent panels like 14 and 16 to be fastened together by conventional T-bolt and wedge assemblies 22 such as shown in U.S. Pat. No. 2,997,769, granted to George F. Bowden on Aug. 29, 1961.

The outside margins of the

ribs

18 and 20 also have aligned dado slots 24 which, when two panel units like 14 and 16 are fastened together, produce holes 28 for receiving the ends of panel ties 26. As will be further described, some of the holes 28 are utilized by the spacer bars of this invention. The second wall from 12 is similar to the first wall form 10 just described and therefore is illustrated only in diagrammatic form.

FIG. 5 shows one embodiment of the spacer bar of this invention which is designated generally as 30. The spacer bar 30 includes a rod member 32 having a first end portion and a second end portion. A reverse bend or hook 34 is formed on the first end, and a fracturable, weakened area 36 is formed between the first and second ends. The weakened area 36 may be conventionally formed as by peening. A spring

means including washers

38 and 40 and a compression type spring 42 are all slidably mounted in encircling, coaxial relation on the rod portion 32 as shown. A perpendicular flange member 44, including

rods

46 and 48, is secured to opposite sides of the second end of the rod member 32 as by spot welding. The terminal ends of the

rods

46 and 48 are bent towards each other and secured together, as by spot welding, to form

slots

50 and 52 which facilitate the wiring of steel mat rods thereto. The flange member 44 has a long dimension which lies in the same plane as the reverse bend 34.

In the embodiment shown, the spacer bar 30 (FIG. 5) may be made of 7/32 inch diameter wire rod. The rod is preferably made from cold rolled steel so as to be sufficiently strong and stiff to hold the steel mat rods. Naturally, the dimensions of the spacer bar 30 are dependent upon a particular application. For example, the reverse bend 34 of the spacer bar 30 should be small enough to pass through a hole 28 (FIG. 1) in the first wall form 10 with which the bar 30 is used. The weakened portion 36 should also be located between the ends of rod member 32 so that, as will become apparent, it will be within the finished concrete wall after the concrete is poured between the wall forms. The length of the spacer bar 30, as measured from the reverse bend 34 to the flange member 44, is such as to enable a steel reinforcing mat, secured to the flange member 44, to be positioned a predetermined fixed distance from the inside surface of the first wall form. This aspect will become clearer when the use of the spacer bar 30 is later described herein.

A second embodiment of the spacer bar, designated generally as 54, is shown in FIG. 6. The spacer bar 54 is identical to spacer bar 30 already described except that it has a provision for maintaining a second reinforcing mat at a fixed, but greater distance away from the inside surface of the first wall form 10. Spacer bar 54 has the same rod member 32, reverse bend 34, fracturable or weakened portion 36,

washers

38 and 40, spring 42, and flange member 44 as does spacer bar 30, so the same reference numerals are used in FIG. 5. In addition, spacer bar 54 has an extended rod portion 56 which extends from the second end portion of rod member 32 and is axially aligned therewith. When making the spacer bar 54, the rod member 32 and the rod portion 56 may be made from one piece of wire rod. The free end of the extended rod portion 56 has a flange member 58 perpendicularly fastened thereto. The flange member 58 is identical to flange member 44 except that it is offset 90 relative to the plane of the reverse bend 34 and the flange member 44. The reason for offsetting the flange member 58 will be explained during a description of its use.

The method of using the spacer bar 30 shown in FIG. will now be discussed in conjunction with the first wall form shown in FIGS. 1 and 4. After the first wall form 10 is erected as previously described, the construction worker who is to install the spacer bars and the reinforcing steel mats will have to determine which holes 28 are to be utilized for the spacer bars 30. The spacer bars 30 are used only for making a template or framework to position the reinforcing steel mat, and consequently there normally would not be a spacer bar 30 for each available hole 28. Naturally, the size and weight of the reinforcing steel mat will determine how close or how far the spacer bars 30 will have to be positioned for a particular steel mat. Bars 30 located on four foot centers would typically be sufficient.

With reference to FIGS. 4 and 5, to install a spacer bar 30 a construction worker grasps the flange member 44 and inserts the reverse bend 34 into a hole 28 from the inside surface 60 of the first wall form 10 and pushes the reverse bend 34 through the wall form 10 against the compressive force of the spring 42 until the reverse bend 34 clears the

ribs

18 and 20. After clearing, the worker rotates the flange member 44 through 90 and then releases the flange member 44 to enable the reverse bend 34 to engage one of the ribs, like 18. The spring 42 remains compressively loaded when the spacer bar 30 is mounted on the first wall form 10 and it maintains the flange member 44 at a substantially fixed distance away from the inside form surface 60. A vertical steel bar or rod 62 of the reinforcing steel mat is then supported on the footing (not shown) on which the first wall form 10 is supported, and the rod 62 is thereafter secured to the flange member 44 by wiring the bar thereto with a wire 64 passing through the

slots

50, 52 of the flange member 44. With several such spacer bars 30 positioned on the inside surface of wall form 10, additional vertical reinforcing bars may be secured thereto and then the horizontal steel reinforcing rods 65 secured by twisted wire to the vertical rods 62 to form the usual grid like pattern of the reinforcing steel mat.

After the reinforcing steel mat is installed, the second wall form 12 is erected, and the two

wall forms

10 and 12 are conventionally tied together by panel ties 26 passing through some of the holes 28. During the pouring of concrete into the forms, the spacer bars 30 will keep the reinforcing steel mat at a substantially fixed distance from the inside surface 60 of the first wall form 10. The washer 38 also keeps the spring 42 recessed within the interior of the concrete wall while the concrete is setting.

It should be noted that the spacer bars 30 can be installed on either the first wall form 10 or the second wall form 12 (depending upon which is erected first) by a single, unassisted workman who works from the inside surface of the erected wall form. The inside surface 60 of some panel units like 14 and 16 is plastic coated, and accordingly should not have any nails driven therethrough; however, no damage is done thereto because the spacer bars 30 are inserted through holes like 28 already existing in the panel units.

When it is time to remove the wall forms, a pair of bolt cutters may be used to cut off the reverse bend 34 of the spacer bar, and the panels like 14 and 16 may be conventionally removed. Either before or after removing the

panels

14 and 16, the exposed rod member 32 may be hit with a hammer or twisted by pliers or the like to fracture the member at the fracturable portion 36 as one would fracture a conventional panel tie 26. The fractured portion of rod 32 is then removed. The washer 38 which abuts against the inside surface 60 of the first wall form 10 may also be removed. Its removal leaves a void which can easily be filled with grout. The rest of the spacer bar 30 including the spring 42, the washer 40, the flange 44 and the adjacent portion of the rod member 32 remain lodged and hidden from view inside the concrete.

With reference to FIGS. l-3 and 6, the spacer bar 54 is used when two reinforcing mats are to be positioned between a pair of spaced wall forms. After the first wall form 10 is erected, spacer bars 54 are installed in selected holes 28 thereof by inserting the hooked ends 34 therethrough as previously explained. After a sufficient number of spacer bars 54 have been so installed, vertical bars or rods 66 of the first reinforcing steel mat are secured to the flange members 44 by wires 68. Horizontal bars 69 are then wired to the vertical rods 66 to complete the first reinforcing steel mat which is spaced from the first wall form 10 by the spacer bars 54. Because the flange member 58 is offset degrees relative to the flange member 44, its long dimension assumes a vertical orientation when the spacer bar 54 is secured to the wall form [0. This feature is useful in constructing the steel mats as reinforcing steel rods may be temporarily horizontally supported on the extended portions 56 of two horizontally displaced spacer bars 54 without fear of the steel mat rods rolling off the spacer bars.

After the first reinforcing steel mat is completed, a second steel mat may be secured to the flange members 58 of the spacer bars 54 as shown in FIGS. 1, 2 and 3. Selected vertical rods 70 of the mat are first secured to the flange members 58 by fastening wire 72. The horizontal bars 73 of the second steel mat are wired to the vertical bars 70 to complete the grid-like, second steel mat. The spacer bar 54 is dimensioned so as to place the second steel mat (as represented by vertical bars 70) a fixed distance away from the inside surface 74 of the second wall form 12, which is erected after the second mat is completed. After erecting the wall form 12, the wall forms and 12 are conventionally secured together by panel ties 26 which are secured to the panel units (14, 16) by conventional wedge assemblies 76. After the pouring and hardening of concrete in the wall forms, the wall forms 10 and 12 may be removed as previously explained in connection with the embodiment shown in FIG. 4. The washer 38 and the portion of the rod from the fracturable portion 36 to the hook 34 are, of course, removed at the same time.

While the spacer bars 30 and 34 are shown being used with spaced, parallel wall forms, they may also be used with spaced wall forms which converge towards each other or with curved wall forms. In some situations requiring a single reinforcing mat as is shown in FIG. 4, there is also a need for a single, floating horizontal bar to be positioned either at the top or bottom of the second wall form 12. If a floating, horizontal bar is to be positioned near the bottom, for example, the lowermost row of spacer bars secured to the first wall form 10 would be the type of spacer bar 54 shown in FIG. 6 while the rest of the spacer bars would be of the type shown in FIG. 5. The floating, horizontal bar would then be secured to the flange members 58 to appropriately space it from the inside surface 74 of the second wall form 12 (FIG. 4).

As mentioned earlier, the length of the rod member 32 will depend upon the dimensions of the wall form and the desired spacing of the steel mat from the wall form. Typical spacings of the steel mat are 2 inches and 1% inches. One length of the rod member 32 can be used for both these dimensions. Approximately two inch spacing may be obtained by mounting the vertical reinforcing mat bars to the side of the flange 44 opposite the hook portion 34 such as shown in FIG. 3. Ap-

proximately 1% inch spacing can be obtained by mounting the vertical bar on the opposite side of flange 44, as shown in FIG. 4. The length of the rod extension 56 will also depend upon the spacing of the two wall forms and the desired spacing between the second steel mat and the second wall form. Those familiar with the industry will appreciate that both embodiments of the invention shown in FIGS. 5 and 6 may be produced in standard sizes. For converging or battered wall constructions, the spacer bar 54 may be manufactured to various lengths. That is, for use in forming concrete walls having sides converging toward one another, the lengths of the rod extensions 56 would be longest near the bottom and decrease to shortest near the top of the wall.

Although the presently preferred embodiments of this invention have been described, it is understood that within the purview of this invention various changes may be made within the scope of the appended claims.

I claim:

1. A spacer bar for maintaining a reinforcing means at a predetermined, substantially fixed distance from the inside surface of a first wall form of a pair of spaced first and second wall forms, said first wall form having slots therein and reinforcing ribs on the outside surface thereof; said spacer bar comprising:

a rod member having first and second end portions said first end portion having rib engaging means:

said second end portion having a flange member secured thereto to facilitate securing said reinforcing means to said spacer bar;

said rib engaging means being dimensioned to pass through one of said slots and, by manual rotation of said rod member, engage one of said ribs to enable an unassisted operator to install said spacer bar from the inside surface of said first wall form; and

spring means including compression spring means mounted on said rod member which contacts said inside surface of said first wall form and is compressed when said rib engaging means passes through one of said slots thereby to resiliently urge said rib engaging means against said one of said ribs and hold said spacer on said form.

2. The spacer bar as claimed in claim 1 in which said rod member has a weakened portion located a predetermined distance from said first end portion whereby said weakened portion is located a fixed distance from the inside surface of the first wall form when the spacer bar is secured thereto.

3. The spacer bar as claimed in claim 1 in which said compression spring means encircles said rod member, said compression spring means being long enough to engage said flange member when in contact with said inside surface of said first wall form and under compression.

4. The spacer bar as claimed in claim 1 in which said flange member is positioned substantially perpendicular to said rod member; said flange member being made of first and second rods which are secured at their midpoints to opposed sides of said rod member at said second end portion; said first and second rods lying substantially in the same plane with one end of each of said first and second rods being secured together, and the other ends of said rods also being secured together.

5. The spacer bar as claimed in claim 1 in which said rod member has an extended portion extending from said second end portion and axially aligned therewith, and further comprising a second flange member secured to the free end of said extended portion;

said second flange member having at least one slot therein to facilitate securing a second reinforcing means thereto;

said extended portion having a predetermined length to enable said second reinforcing means to be positioned a fixed distance away from the inside surface of said second wall form when said spacer bar is installed on the said first wall form.

6. The spacer bar as claimed in claim 5 in which said first named flange member is positioned substantially perpendicular to said rod member and said second flange member is positioned substantially perpendicular to said extended portion, said first named flange member and said rib engaging means lying substantially in a first imaginary plane and said second flange member lying substantially in a second imaginary plane which is perpendicular to said first imaginary plane.

7. The spacer bar as claimed in claim 1 in which said rib engaging means is formed by reversely bending said first end portion of said rod member, said reverse bend being hooked to said one of said ribs when said spacer bar is installed on said first wall form.

8. A spacer bar for maintaining reinforcing steel bars of a reinforcing mat at a predetermined, substantially fixed distance from the inside surface of a first wall form of a pair of spaced first and second wall forms for concrete, said first wall form having slots therein, said spacer bar comprising a rod member, form engaging means on said rod member shaped to pass through one of said slots and, by manual rotation of said rod member, engage the outside surface of a first wall form adjacent to said one of said slots, retaining means on said rod member for engaging the inside surface of said first wall form adjacent said one of said slots for retaining surface.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION .PATENT N0. 3,861,096 r I DATED January 21, 1975 lM/ENIQMS) I Harold R. Emmons is (erhfied that error appears in the above-identified patent and that said Letters Patent are her-shy conected as shown below:

Abstract line 7, after "wall" insert ---form---.

Column 2, line '43, "from" should be ---form---. Column 5, line 25, "3 should be 54 Column 8, line 12, "an" should be ---and---.

Signed and sealed this 14th day of June 1975.

=3 up. fittest:

C MARSHALL DA'NN RUTH C. MASON Attesting Officer and Trademarks Commissioner of Patents

Claims

1. A spacer bar for maintaining a reinforcing means at a predetermined, substantially fixed distance from the inside surface of a first wall form of a pair of spaced first and second wall forms, said first wall form having slots therein and reinforcing ribs on the outside surface thereof; said spacer bar comprising: a rod member having first and second end portions said first end portion having rib engaging means; said second end portion having a flange member secured thereto to facilitate securing said reinforcing means to said spacer bar; said rib engaging means being dimensioned to pass through one of said slots and, by manual rotation of said rod member, engage one of said ribs to enable an unassisted operator to install said spacer bar from the inside surface of said first wall form; and spring means including compression spring means mounted on said rod member which contacts said inside surface of said first wall form and is compressed when said rib engaging means passes through one of said slots thereby to resiliently urge said rib engaging means against said one of said ribs and hold said spacer on said form.

5. The spacer bar as claimed in claim 1 in which said rod member has an extended portion extending from said second end portion and axially aligned therewith, and further comprising a second flange member secured to the free end of said extended portion; said second flange member having at least one slot therein to facilitate securing a second reinforcing means thereto; said extended portion having a predetermined length to enable said second reinforcing means to be positioned a fixed distance away from the inside surface of said second wall form when said spacer bar is installed on the said first wall form.

8. A space bar for maintaining reinforcing steel bars of a reinforcing mat at a predetermined, substantially fixed distance from the inside surface of a first wall form of a pair of spaced first and second wall forms for concrete, said first wall form having slots therein, said spacer bar comprising a rod member, form engaging means on said rod member shaped to pass through one of said slots and, by manual rotation of said rod member, engage the outside surface of a first wall form adjacent to said one of said slots, retaining means on said rod member for engaging the inside surface of said first wall form adjacent said one of said slots for retaining said form engaging means engaged with said outside surface, and a flange member spaced from said inside surface of said first wall form and between said first and second wall forms to facilitate securing a reinforcing bar thereto, said retaining means including a compression spring surrounding said rod, which, when said bar is assembled onto said first wall form, is under compression an coacts between said inside surface of said form and said flange member thereby to urge said form engaging member into engagement with said outside surface.