Reinforcing bar tool and method

A tool for forming a high strength reinforcing bar coupling driving self-locking wedge sleeves over each end of a contractible jaw assembly bridging the abutting ends of the bar to be joined. The sleeves are seated in collars engaged by the distal ends of arms driven for closure by a piston-cylinder power unit and a cam on at least one arm. In one form the cam on one arm is engaged by a roller connected by a tension link to the other arm. In another form cams are provided on each arm driven by rollers fixed with respect to each other. The collars include self-releasing collets seating the sleeves. The tool has other uses such as bar shearing or forming.

This invention relates generally as indicated to reinforcing bar tool and, more particularly, to a tool and method for quickly field or shop cutting, forming or coupling reinforcing bar.

BACKGROUND OF THE INVENTION

In a prior application there has been developed a reinforcing bar splice or coupling which involves driving a low angle self-locking wedge sleeve over each end of a contractabile jaw assembly causing the jaw assembly to close and engage or grip abutting bar ends to form a high strength splice or coupling. The jaw assembly includes teeth which may cold form, engage, and grip the bar ends penetrating the overall diameter of the bar but not the nominal bar diameter or core. In this manner a high strength connection is formed. When correctly assembled, the bar coupling forms a high compressive and tensile strength coupling qualifying as a Type 2 mechanical connection in all United States earthquake zones. The coupling has been developed by ERICO International Corporation of Solon, Ohio, U.S.A., under the trademark LENTON® LOCK™. LENTON® is a registered trademark of ERICO.

While forming such a high strength coupling is a relatively easy task in a lab or shop using elaborate power bench equipment such as presses, field forming these high strength couplings is an entirely different matter. Such couplings can be used horizontally or vertically in columns, or even diagonally. The installation may be at considerable height, in very limited space, and in all kinds of weather conditions. There is probably no work environment more confining, complex and difficult than the arduous installation and erection of steel reinforcing for concrete construction. Laboratory or plant equipment simply is not suitable in a field application. There is, accordingly, a need for a tool useful both in the field or shop for forming such high strength connections or couplings. It would also be desirable if the tool had other uses and applications in the steel reinforced concrete contraction industry.

SUMMARY OF THE INVENTION

It is, accordingly, an object of the inventor to provide a tool which can quickly make high strength couplings in the field as well as in a shop. It is also an object to provide a tool fully field capable of installing multiple reinforcing bar coupling sizes and which may be automated, obtain a mechanical advantage, provide a constant closing force range at the end of the closing stroke, and which may use variable power requirements to adjust the force applied depending on bar size. It is a further object to provide a tool having other uses in reinforced concrete construction such as bar shearing or bending.

It is an aspect of the invention to provide a tool for forming a reinforcing bar connection having opposed drivers each adapted to engage a collar seating a tapered sleeve, with the collars and the tapered sleeves positioned over bar ends, the collars being driven axially of the bar ends to force the sleeves over the opposite ends of a jaw assembly positioned on the bar ends to cause the jaw assembly to contract and grip the bar ends.

It is another aspect to provide a tool for forming a reinforcing bar splice having a pair of pivoting arms, the distal ends of which engage and drive oppositely facing sleeve seats positioned over aligned bar ends, with power means to drive the seats axially of the bar ends to force the sleeves over the jaw assembly positioned on the bar ends to cause the jaw assembly to contract to grip and splice the bar ends.

It is yet another aspect to provide a method of forming a reinforcing bar coupling comprising the step of placing oppositely directed self-locking wedge sleeves over the butting ends of the reinforcing bar to be joined, placing a contractible jaw assembly over the butting ends, seating the sleeves in collars, and then activating a driving tool to force the collars and wedge sleeves toward each other and over the jaw assembly to contract the jaw assembly and form the coupling.

It is also an important aspect of this invention to provide a power operated rebar tool having pivoting arms with the distal end of each arm provided with a notch accommodating reinforcing bar, each distal end also including a bearing section on each side of the notch operative to engage and drive rebar tooling when the arms are closed.

To the accomplishment of the foregoing and related ends, the invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially toFIGS. 1 through 3, there is illustrated a tool shown generally at20which comprises an upper arm21and a lower arm22which are coaxially pivoted together at their proximal ends as indicated at23. A distal or outer end of each arm is provided with a notch, shown at25and26, respectively, the notch extending in the plane of movement of the arms which would be the plane ofFIG. 1or normal toFIG. 2. When the tool is utilized to form a coupling, the notches accommodate reinforcing bar passing therethrough.

As seen more clearly inFIG. 3, the distal end of each arm includes the bearing section on each side of the notch which is operative to engage and drive rebar tooling when the arms are closed. Each bearing section is rounded or curved and for the distal end of the upper arm21the bearing sections are shown at27and28. For the distal end of the lower arm the bearing sections are shown at29and30. The bearing sections engage the tooling diametrically opposite any bar or rod passing through the notch and the rounded configuration of the bearing sections maintains the desired contact with the tooling being used with the tool.

As can be seen inFIG. 3, the upper arm21includes a proximal clevis or fork33, which accommodates the proximal end of the lower arm22and enables the arms to be pivoted together by the pin34, forming the pivot23.

Also mounted on the pivot pin34is a support bracket shown generally at36which provides a pivot support37at the rod end piston-cylinder assembly40. The bracket36has two upstanding arms on each side of the cylinder seen at41and42with the cylinder pivot being held in place by removable keepers43at the upper end of each arm. The bracket36fits snugly over and under the proximal end of the upper arm21and is thus a rigid extension of that arm.

The rod46of the piston-cylinder assembly is connected to a clevis47which has separated arms48and49supported by spherical bearings50on shaft51. Also mounted on the shaft, each with its own spherical bearing are the eyes53and54of tension links55and56, respectively, as well as cam roller58. The cam roller58is in the center of the pivot pin and may be slightly flanged to ride on cam surface60on the top of the upper arm21.

The eyes62and63at the lower end of the tension links55and56are supported by spherical bearings on the ends of pivot pin64pivotally connecting the tension links to the lower arm22.

It can now be seen that as the piston-cylinder assembly40extends, the roller58will ride over the cam60causing the arms to pivot about their proximal ends toward each other, closing the tool for a variety of tasks such as forming a rebar coupling, shearing or cutting rebar, or forming or bending rebar.

As seen more clearly inFIG. 1the upper pivoting arm21is provided with a hole66which may accommodate a handle which may manually open the arms when the piston-cylinder assembly is retracted. Return springs may also be provided if desired.FIG. 1also illustrates schematically a hydraulic circuit for the piston-cylinder assembly40which includes a power supply67and a pressure regulator68supplying fluid pressure to the blind end of the piston-cylinder assembly as indicated at69. The pressure regulator may also be controlled from a controller70, in turn controlled by a proximity switch71positioned in the receiving end of the distal end of the lower arm22. The proximity switch is positioned a distance from the diametral bearing surfaces29and30and is used to sense the size of the reinforcing bar being accommodated by the tool. In this manner the sensor will recognize the reinforcing bar size and through the pressure regulator will automatically adjust the fluid pressure for the size of bar positioned in the tool.

As can be seen, the embodiment ofFIG. 1has coaxially pivoted arms and a single cam60which is the upper edge of the upper arm21. The cam60is selected so that the concluding portion of the closing stroke generates a constant closing force range. This accommodates variations in reinforcing bar diameter, per nominal size, and the tool automatically stops when appropriate closing force is achieved. A sensor may be provided both to notify the operator when the proper coupling connection has been made and to reverse the piston-cylinder assembly.

Referring now toFIGS. 4 and 5there is illustrated another embodiment of a tool in accordance with the present invention shown generally at75. This illustrated embodiment of the tool includes two pivoting arms76and77proximally pivoted at pins78and79, respectively, to rod end cylinder bracket80. The distal ends of the arms are provided with removable projecting receivers indicated at83and84, respectively, each having a notch as seen at85and86. Each receiver also includes the diametrically opposed rounded bearing surfaces seen more clearly inFIG. 5at87and88.

The piston-cylinder assembly90is joined to the arms through the bracket80, and the rod91has secured to the end thereof a triangular yoke92which supports the apex of two laterally spaced triangular trusses shown generally at95and96. Each truss includes angularly related compression members97and98and a tension member99connecting pins100and101at each end through the eyes shown at102and103, respectively. Positioned between the eyes of the laterally spaced trusses are cam rollers shown generally at104and105. The eyes of the spaced trusses as well as the cam rollers may be mounted on the respective pins100and101each with suitable spherical bearings. The cam rollers104and105engage cams107and108, respectively, which are removably mounted on the exterior of the pivoting arms76and77, respectively.

With the tool ofFIGS. 4 and 5the proximal ends of the arms are pivoted offset from each other on each side of the piston-cylinder assembly90, and cams on both arms are engaged by respective rollers on the ends of the trusses to translate the linear movement of the power means to closing movement of the arms. A return spring may be provided between the two arms urging the two arms to an open position. In any event as pressure in the piston-cylinder assembly at the blind end moves the rod91to the right as seen inFIGS. 4 and 5, the two arms pivot toward each other closing the receivers83and84on the reinforcing bar tooling within the receivers either to form a coupling, cut or shear reinforcing bar, or form it, for example.

Referring now toFIGS. 6,7and8there is an illustration of the tool forming a LENTON® LOCK™ coupling in accordance with the invention. InFIG. 6the tool is open and the receiver or distal ends of each of the arms is positioned, respectively, above and below collars112and113positioned at each end of the splice114forming the coupling joining the reinforcing bars115and116end-to-end. The coupling splice114is shown in greater detail inFIG. 11 and 12hereinafter described.

As seen inFIG. 8the collars112and113may be formed from half-round collar sections120each of which includes a tapered opening122which in turn supports a self-releasing collet section shown generally at123. The collet section is supported in the collar section by a series of sloping surfaces indicated at124so that when the pressure of the tool is released, the collet sections will release the self-locking wedge sleeves seen in more detail inFIG. 11. The half-round collar sections are provided with slots125and126on one side and slots127and128on the other side. These slots are designed to receive keys shown at129inFIGS. 6 and 7which hold the two halves of the collar together forming the annular seat for the wedge sleeve.

As seen in comparingFIGS. 6 and 7the piston-cylinder assembly40has been extended and the arms have closed with the round bearing surfaces engaging diametrically opposite sides of the collar formed by the half-round sections driving the wedge sleeves toward each other and over the coupling jaw assembly114. This causes the jaw assembly to contract to grip the end-to-end bars115and116forming a Type 2 splice. When the assembly is completed, the tool is removed and the collars112and113are disassembled and removed for reuse.

Referring now toFIG. 9, it will be seen that the same tool20is being used to operate a bar shear fixture shown generally at135. The upper and lower blade assemblies136and137are connected by two guide rods seen at138and139each surrounded by a return compression spring140and141. The shearing blade assemblies are provided with oppositely projecting, relatively short rods indicated at143and144. The curved bearing areas of the distal ends of the arms engage shoulders145and146on opposite sides of the rod extension. In this manner the tooling may quickly be driven to a closed or shut position shearing bar150.

FIG. 10illustrates a bar bending or forming fixture which includes male tooling element154and female element155positioned in the receiver ends of the arms of the tool. Like the shear tooling, the male tooling154includes a rod extension156filling in notch25providing shoulders157and158on each side thereof to be engaged by the bearing areas of the distal end of the upper arm. Similarly, the female tool155includes rod extension160fitting in the notch26with shoulders161and162on each side for engagement by the bearing areas of the distal end of the lower arm. Using the tooling illustrated, the bar164may quickly be bent to the desired configuration.

Referring now toFIGS. 11 and 12there is illustrated a LENTON® LOCK™ coupling which the tool of the present invention completes. The coupling shown generally at114is joining end-to-end axially aligned deformed reinforcing bars115and116. The bars are, of course, shown broken away so that only the ends gripped by the splice or connection are illustrated. The connection comprises a jaw assembly shown generally at168which includes three circumferentially interfitting jaw elements shown at169,170and171. InFIG. 12the jaw element170has been removed. The exterior of the jaw elements form oppositely tapering, shallow angle surfaces172and173on which the tool of the present invention drives the matching taper lock sleeves174and175. It is noted that the jaw sections have interfitting portions indicated at176keeping the jaw elements properly assembled. When the locking sleeves are driven toward each other by the tool of the present invention, the jaw assembly contracts driving the interior teeth178on each jaw element into the deformed, or projecting portions of the bar such as the longitudinally projecting ribs179or the circumferential ribs180, but not the core181.

The diameter bar at the core represents the nomial diameter of the bar while the overall diameter includes the longitudinal or circumferential ribs. In any event, the tool of the present invention can quickly complete the coupling seen inFIG. 11.

Referring now toFIG. 13, there is illustrated another tool shown generally at190for completing the splice or connection of the present invention. Although the tool is shown connecting the bars115and116vertically oriented, it will be appreciated that the bars and splice may be horizontally or even diagonally oriented. The tool includes generally parallel levers191and192connected by center link193pivoted to the approximate mid-point of such levers as indicated at194and195. Connecting the outer or right-hand end of the levers191and192is an adjustable link shown generally at196in the form of a piston-cylinder assembly actuator197. The rod198of the assembly is provided with a clevis199pivoted at200to the outer end of lever191. The cylinder201of the assembly197is provided with a mounting bracket or clevis202pivoted at203to the outer end of lever192.

The opposite end of the lever191is provided with a C-shaped termination pivoted at204to a C-shaped tubular member205having an open side206. A wedge driving collar shown generally at207is mounted on the lower end of the open tube205. The collar is formed of hinged semi-circular halves208and209. When closed and locked the wedge collar has an interior taper matching that of the self-locking sleeves174and175.

The lower arm192is provided with a C-shaped termination210pivoted at211to open tube212supporting wedge collar213formed of pivotally connected semi-circular halves214and215. When the piston-cylinder assembly is extended, the collars are driven toward each other.

In any event, with the various tool embodiments of the present invention the splice as illustrated inFIG. 11can quickly and easily be made.

The tool of the present invention is capable of installing multiple rebar splice sizes and automatically stops when appropriate closing force is achieved. The tool accommodates variations in rebar diameter, per nominal size, by means of a constant closing force range at the concluding portion of the closing stroke and will function with all types and grades of rebar. The tool provides quick installation times for a bar break coupling in but one actuation of the tool. The tool can, however, perform other tasks in the rebar construction industry such as bar shearing or bar forming or bending.

Although hydraulic piston-cylinder assemblies and controls are preferred, it will be appreciated that other types of power actuators may be employed. The preferred form of tool seen, for example, inFIG. 1provides force multiplication obtained through the combination of the power unit in conjunction with mechanical cam surface and the rotating tension link. Multiplication also can be achieved with the combination of the power unit and mechanical cams with the translating truss assembly of theFIG. 4embodiment.

The tool is versatile, light weight, and may have a variety of uses in the steel reinforced concrete construction industry. For example, the components of the tool may be made of 4140 steel and the tool is readily portable at a field or construction site.

To the accomplishment of the foregoing and related ends, the invention then comprises the features particularly pointed out in the claims, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.