US3694012A

US3694012A - Reinforcing bar coupling

Info

Publication number: US3694012A
Application number: US873834A
Authority: US
Inventors: Leonard Gelfand
Original assignee: Erico Products Inc
Current assignee: Erico International Corp
Priority date: 1969-11-04
Filing date: 1969-11-04
Publication date: 1972-09-26
Anticipated expiration: 1989-09-26
Also published as: JPS5016899B1; FR2100593A1; FR2100593B1; DE2045456A1; GB1297427A; BR7019577D0; CA924924A

Abstract

A coupling for concrete reinforcing and like bar particularly suitable for compressive loading which comprises a generally Ushape element adapted to embrace the butted ends of such bar with transverse clamp straps extending between the legs of such element being individually tightenable so that the coupling can be secured first to one bar and then the other.

Description

0 United States Patent [151 3,694,012 Gelfand Sept. 26, 1972 [54] REINFORCING BAR COUPLING 1,193,642 8/1916 Wallace ..287/110 UX 72 I e t Le rd G F l 1 n ,32 e a S 3,340,667 9/1967 Reiland ..52/726 x 3,452,375 7/1969 Gabbey ..151/22 X [73] Assignee: Erico Products, Inc., Cleveland,

Ohi FOREIGN PATENTS OR APPLICATIONS [22] Filed: Nov. 4, 1969 489,838 8/1938 Great Britain "287/1 11 [211 App! 873834 Primary Examiner-David J. Williamowsky Assistant ExaminerWayne L. Shedd [52] U.S. Cl ..287/110, 52/726, 24/249 PR, Attorney-Oberlin, y, Donnelly & Renner 287/111 I [51] Int. Cl ..F16b 2/08 [57] ABSTRACT [58] held of Search A coupling for concrete reinforcing and like bar particularly suitable for compressive loading which comprises a generally U-shape element adapted to em- [56] References C'ted brace the butted ends of such bar with transverse UNITED STATES PATENTS clamp straps extending between the legs of such element being individually tightenable so that the 3,141,688 7/1964 Taylor et a1 ..24/279 X couplingcan be Secured first to one bar and then the 3,554,583 1/1971 Lowe ..287/110 other.

943,469 12/1909 Schade ..52/726 X 847,620 3/1907 Thompson ..24/284 8 Claims, 3 Drawing Figures yl i PATENTED 3.694.012

HE NH 1 D F I I 45 ZARA 1 S2; "M HJ 45 H HEEQH 2'4 :2 w "I!" [m "H 1 3; m 5?: II 22 g 4? WM ill :3 i "I, Z3 27 fl I 48 '2 37m I" 49 INVENTOR LEONARD GEL FAA/0 BY. I

, awwamwag 6m REINFORCING BAR COUPLING This invention relates generally as indicated to a reinforcing bar coupling and more particularly to an improved reinforcing bar coupling and more particularly to an improved reinforcing bar coupling for concrete construction where substantially compressive loads only are involved.

l-leretofore, split metallic sleeves utilizing a wedge to contract the sleeve about the adjacent ends of reinforcing bars in concrete column construction have been employed. However, before the coupling can be effected, the reinforcing bars must be in place, the upper bar usually being held by a crane, and a heavy hammer must be employed to drive the wedge downwardly into its operative position. An ironworker then climbs the column, aligns the bars, and makes the coupling. Sometimes special costly scafi'olding is required.

Also, a wedge-type splice requires support for the clamp, otherwise it may be driven down onto the lower bar. Such clamps may also require the use of a vice grip type of pliers or similar clamping tool to hold the clamp in place while it is being installed. Needless to say, once secured by the wedge, they are extremely difficult to remove and cannot usually be reused.

When reinforcing bars are preassembled in cage form such costly cranes are usually employed to hold the cage in position while the workman climbs the column and secures such sleeves in place then driving the wedge home with such relatively heavy hammer, the operation of which usually requires both hands. This is a time consuming operation and with such hammer an arduous and even dangerous task.

Where a multiplicity of bars are used as in a cage, there may be not be sufficient clearance to enable the worker to take a full swing with the hammer, thus adding to the task and time required. The time involved also requires the use of costly crane time supporting the reinforcing bar or cage of reinforcing bars while the connection is made.

Even though reinforcing bar may be of the same nominal size, there can be considerable variation in diameter due to roll wear and other factors. Accordingly, it is desirable to provide a splice which can be independently tightened on each bar end. With the aforementioned wedge type lock it is possible to drive the clamp shut and still have a loose connection to one bar end, with no restraint other than the weight of the upper bar.

It is therefore a principal object of the present invention to provide a simplified coupling for reinforcing bar not requiring the time or effort of prior art couplings.

Another important object is the provision of such coupling which can be secured first to the end of one bar and then quickly secured to the other.

A further object is the provision of a reinforcing bar coupling having a vertically elongated generally U- shape member with a plurality of transverse clamps adapted to be connected between the legs of said member and individually tightened against a bar therein.

Still another object is the provision of a reinforcing bar coupling utilizing a plurality of vertically spaced clamp stra s which may be individually tightened against the bar.

A yet further object is the provision of a reinforcing bar coupling which can be quickly secured in place with the use 0s a lightweight tool such as a ratchet wrench.

A still further object is the provision of a reinforcing bar coupling comprising an elongated U-shape clamp adapted to embrace the butted ends of reinforcing bar with a plurality of clamp straps bridging the legs of such clamp and secured thereto by special fasteners permitting the use of a ratchet wrench, for example.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described, the following description and the annexed drawing setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principles of the invention may be employed.

In said annexed drawing:

FIG. 1 is a side elevation of a: reinforcing bar coupling in accordance with the present invention secured to the end of one bar to be joined;

FIG. 2 is a view similar to FIG. 1 illustrating the second bar secured in place; and

FIG. 3 is an enlarged horizontal section taken substantially on the line 33 of FIG. 2 showing the manner in which the clamp straps are secured to the elongated U-shape clamp element.

Referring now to FIGS. 1 through 3, 10 illustrates the upper end of a reinforcing bar which is vertically disposed having square cut end 11. Such bar is provided with an outer surface pattern of ridges seen at 12 in conventional manner.

A couplingshown generally at 14 is employed to secure the bar end 10 to bar end 15 disposed thereabove. Such bar end 15 is provided with a square cut end 16 which butts against the upper square cut 11 of the bar end 10.

The coupling is particularly designed for reinforced concrete column construction for holding two reinforcing bars to be joined in axial alignment, the ends of the bars being square cut to transmit the compressive stress from one bar to the other.

The coupling 14 comprises a main vertically elongated generally U-shape coupling element 20 adapted to embrace the reinforcing bar as seen more clearly in FIG. 3. The main body portion of the coupling element is of circular section thus to embrace the bar and the element includes vertically

elongated legs

21 and 22. The leg 21 extends tangentially of the circular main body portion and is provided with a series of vertically spaced elongated apertures as seen at 24, 25, 26 and 27. The

apertures

24 and 25 are spaced from each other the same distance as the

apertures

26 and 27. The arrangement of the apertures is thus symmetrical with respect to the center of the clamping element. The clamping element may be provided with a single center aperture as seen at 29 in FIG. 1.

The opposite leg 22 is bent approximately radially of the bar to form a substantially radially extending flange. Such flange is provided with a series of circular apertures indicated at 30 in FIG. 3 each corresponding to and having the same spacing as the elongated apertures 24 through 27 in the opposite leg of the clamping element. Secured to one side of the flange leg 22 and aligned with such apertures are relatively small nuts 31.

Such nuts may be spot welded to the flange as indicated at 32. There are thus four such apertures and four such nuts, each being opposite the centers of the vertically elongated slots 24 through 27 in the opposite leg 21.

A plurality of clamping straps or bars are provided adapted to bridge the legs of the element 20 as seen more clearly at 34, 35, 36 and 37. The configuration of the transverse clamping bars is seen perhaps more clearly in FIG. 3 and it will be appreciated that each such transverse bar includes a center curved or bent' in the form of a bolt. A washer as seen at 49 is provided. Preferably, the washer 49 is built-in or connected to the bolt. The washer may be formed with the head in the foregoing operation to provide, for example, a flared head.

The first few threads on the end of the bolt as seen at 50 may be normal threads permitting the bolt and washer assembly readily to be hand inserted through the slot 43, the aperture 30, and initially threaded into the nut 31. The remaining threads on the'bolt are imperfect or intentionally roughened to provide a degree of frictional resistance to the bolt turning within the nut. This permits the use of a relatively lightweight ratchet wrench for the final tightening of the bolt and nut. The frictional resistance permits the ratchet wrench to have its ratcheting action rather than just allowing the bolt to spin while it is being tightened.

It will be appreciated that other types of resistance fasteners may be employed such as lock nuts or nylon insert nuts. In any event, such type of fastener permits the erector to lock the coupling in place on the two bar ends with only one hand in a matter of a very few seconds.

As the fastener is tightened, it will be appreciated thatthe transverse clamp bars will be brought tightly to bear against the surface of the reinforcing bars and and that the hook and eye connection of the opposite end of the clamp bar with the leg 21 provides a fulcrum at 52. In any event, as the fastener is tightened, the clamp element as well as the transverse bars will be brought tightly to bear against the outer surface of the reinforcing bar.

In operation, the coupling may be secured to the upper end of the lower bar 10 and the

fasteners

47 and 48 only fully tightened. The

upper fasteners

45 and 46 may be merely initially only hand tightened. The erector may use the center aperture 29 as a guide for positioning the upper square cut 1 1 of the bar 10in the approximate middle of the coupling.

A crane will then position the bar 15 such that its lower end may simply be inserted into the top of the upstanding coupling and when in such position, the

upper fasteners

45 and 46 may quickly be tightened with such ratchet wrench to provide the final coupling of the bars as seen in FIG. 2.

,When erecting a cage or preassembled section of reinforcing bars in column construction, the coupling may be secured, for example, to the four corner bars as in FIG. 1 and the cage may then simply be lowered into position until the comer bars fit within the upstanding couplings on the ends of the lower bars. The top two fasteners are then tightened firmly to secure the cage in place. Additional couplings may then be added without the requirement of the crane to secure the cage. In this manner, it can be seen that the crane time required for the erection of the steel reinforcing bars is greatly reduced.

It can now be seen that there is provided a highly simplified reinforcing bar" splice particularly suitable for reinforced concrete column construction. The coupling can be preliminarily joined to one bar, either the upper or the lower, and then very quickly permanently secured to the other to complete the joint, all in a matter of seconds. Moreover, the erector need not carry and wield heavy hammers for the driving of wedges commonly used in conventional splices. Needless to say, a 4 pound hammer weights considerably more than a ratchet wrench and is more difficult to use, particularly in close quarters.

If the upper bar is of reduced diameter, it will be appreciated that a split shim sleeve may be employed surrounding the smaller bar end to bring it substantially to the diameter of the other. Also it will be appreciated that more than the four transverse clamps illustrated may be employed.

It cannow be seen that there is provided a highly simplified reinforcing bar splice which can be used very quickly to join reinforcing bar for concrete construction.

It will be appreciated that the splice of the present invention has little or no tensile capabilities and should such be required, a splice such as shown in US. Pat. Nos. 3,234,603 and 3,255,498 should be employed.

1, therefore, particularly point ,out and distinctly claim as my invention:

1. A coupling for reinforcing and like bars comprising a vertically elongated and continuous U-shape member having two legs and being adapted embracingly to bear against one side of the butted ends of such bars, one leg terminating in a portion extending generally tangentially to said bars and the other leg terminating in a flange extending generally radially of said bars, and a plurality of relatively narrow transverse clamps connected between the tangential portion and flange of said legs and adapted to be individually tightened against the opposite side of such bars.

2. A coupling as set forth in claim 1 wherein said transverse clamps are hooked in vertically elongated apertures in such tangentially extending leg.

3. A coupling as set forth in claim 1 wherein said transverse clamps are secured to said radially extending flange leg by threaded fasteners.

4. A coupling as set forth in claim 3 including nuts secured to said radially extending flange leg whereby said fasteners may be inserted and tightened with one hand.

5. A coupling as set forth in claim 3 including elongated slots extending longitudinally of said transverse clamps through which said fasteners extend.

stantially open to permit concrete intrusion into the coupling in use.

8. A coupling as set forth in claim 7 including at least two said transverse clamps engaging each bar end bridging the legs of said member.

t t k a:

Claims

6. A coupling as set forth in claim 1 wherein said transverse clamps are symmetrically arranged longitudinally of said member whereby said joint can be partially assembled on one bar end only.

7. A coupling as set forth in claim 1 wherein the opposite side of such bars engaged by said clamps is substantially open to permit concrete intrusion into the coupling in use.