US3512383A

US3512383A - Re-bar bender

Info

Publication number: US3512383A
Application number: US818193A
Authority: US
Inventors: Ray E Arnold; Charles A Arnold
Original assignee: DIGITAL MACHINES Inc
Current assignee: DIGITAL MACHINES Inc
Priority date: 1969-04-21
Filing date: 1969-04-21
Publication date: 1970-05-19
Anticipated expiration: 1987-05-19

Description

May 1'9, 1970 R, E; ARNOLD ETAL 7 3,512,383

RE-BAR BENDER I v Original Filed Dec. 27, 1966 2 Sheets-Sheet 1 INVENTORS. 184) E: [IQ/V040 Afro/evens United States Patent 3,512,383 RE-BAR BENDER Ray E. Arnold, San Diego, and Charles A. Arnold, Palo Alto, Calif, assignors, by mesne assigmnents, to Digital Machines, llnc., San Diego, Calif., a corporation of California Continuation of applications Ser. No. 604,693, Dec. 27,

1966, and Ser. No. 751,674, July 25, 1968. This application Apr. 21, 1969, Ser. No. 818,193

Int. Cl. B21j 7/26 US. Cl. 72-22 Claims ABSTRACT OF THE DISCLOSURE Disclosed is a bending apparatus which is adapted to semi-automatically form bends in reinforcing bars, rods, and the like. Provision is made for forming successive bends having precisely the same degree of bend, or having a plurality of bends of predetermined degree.

This application is a continuation of Ser. No. 604,693, filed Dec. 27, 1966, and Ser. No. 751,674, filed July 25, 1968, now abandoned.

The present invention relates to bending apparatus, and more particularly to an apparatus for bending reinforcing bars, rods, wires and the like into various forms for use in structural reinforcement of concrete and the like.

Heretofore, bending machines for forming reinforcing bars were cumbersome, slow, difficult to operate, and generally almost completely manually operated. The accuracy and repeatability of bends depended upon the skill of the particular operator so that repetitive formation of identical precision bends was virtually impossible. Moreover, most prior art bending machines are incapable of quickly and easily forming compound or sequential bends in a single length of reinforcing bar. Such machines generally require an inordinate amount of time to convert them from the formation of one angle of bend to another angle of bend.

Accordingly, it is an object of the present invention to provide a bending apparatus which is adapted to semiautomatically form bends in reinforcing bars, rods, and the like. A related object of the invention is the provision of such an apparatus for forming successive bends having precisely the same degree of bend, or having a plurality of bends of predetermined degree, according to the particular job requirements.

A further object of the invention is the provision of such an apparatus for automatically forming successive bends of predetermined but different degrees in a single length of reinforcing bar, so that the operator is required only to advance the bar stock for the successive bends.

Yet another object of the invention is the provision of such a bending apparatus which includes a control unit which can be programmed in advance so that the bending apparatus will provide a single forward or a single reverse bend to any desired angle, and repetitively if desired, and wherein the control unit is also adapted to permit the selected bend angle to be quickly reprogrammed to a different angle if necessary, and is further adapted for programming up to three sequential bends.

A further object is the provision of such an apparatus in which the bending mechanism or head is normally returned to a predetermined start position automatically after each bend.

Yet another object of the invention is the provision of such a bending apparatus which includes a foot-operated switch that, when released, automatically reverses the bending head to its start position, regardless of whether or not the programmed bend has been completed. Such apparatus additionally incorporates a switch that is ice manually operable at any time to instantly stop bending head movement, whether such movement is proceeding in a forward or a reverse direction.

A further object of the invention is to provide such a bending apparatus which can be quickly converted from the bending of one size of reinforcing bar to the bending of a variety of other sizes of reinforcing bar.

Other objects and features of the invention will become apparent from consideration of the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a perspective view of a bending apparatus according to the present invention;

FIG. 2 is a plan view of the work table of the bending apparatus, showing the bending head forming a bend in a length of reinforcing bar;

FIG. 3 is a view substantially identical to that of FIG. 2, except that the bending head is bending a larger size reinforcing bar, and the position of certain components of the apparatus have been altered to accommodate the larger .size bar;

FIG. 4 is a longitudinal cross-sectional view of the bending apparatus;

IgIG. 5 is an enlarged view taken along the line 5-5 of PI 4;

FIG. 6 is an enlarged front elevational view of the control unit of the bending apparatus;

FIG. 7 is a detail view taken along the line 7-7 of FIG. 4; and

FIG. 8 is a wiring diagram of the circuitry of the bending apparatus.

Referring now to the drawings, there is illustrated a bending machine or apparatus 10 which comprises, generally, a frame 12, to which are mounted the various components of the apparatus 10; a motor 14 which is coupled through a gearbox or transmission 16 to a right angle speed reducer 18; a pinion gear 20 rotatable by means of a suitable coupling to the speed reducer 18; a large bull gear 22 which is rotatable by the pinion gear 20, and which is coupled to a band head 24; a limit or bend switch 26 which is actuated upon rotation of the bend head 24; and a control unit 28 which is coupled to the output of the speed reducer 18 and is in circuit with the bend switch 26 so that it is adapted to precisely control the arc of rotation through which the bend head 24 moves to thereby control the degree of bend in the item being bent or deformed. A length of reinforcing bar 30 is shown in FIGS. 2 and 3 for illustrative purposes.

The frame 12 includes a floor plate or base 32 to which are welded a plurality of upstanding plates or walls 34 which support a horizontally-oriented plate or work table 36 characterized by a relatively large, centrally-located, circular opening which rotatably accommodates a head plate or turntable 38 which constitutes a part of the bend head 24, as will be seen.

'The bending apparatus 10 is subject to comparatively high stresses and for that reason the frame components are of relatively heavy construction so as to bear the anticipated loads without appreciable deflection.

The work table 36 supports the control unit 28 in any suitable fashion, as by a pair of legs 40 extending from the unit 28 and affixed to the top of the work table 36.

An elongated adjustable stop member 42 is carried by the work table 36 adjacent the turntable 38 and serves as a surface against which the bar 30 is forced to effect bending of the bar. The stop member 42 is longitudinally, slidably carried in an elongated sleeve 44 in a manner so that it will not rotate. The sleeve includes one or more brackets 46 which are rigidly secured to the work table 36 by a plurality of bolts 48 to fix the sleeve 44 in position. The sleeve 44 threadably mounts a screw 50 which bears against the stop member 42 and is threadably advanced and retracted to move the stop member 42 toward and away from the center of the turntable 38. The inner end of the stop member 42 preferably carries a roller 52 to reduce friction during engagement between the reinforcing bar 30 and the stop member 42 during a bending operation.

In the start position of the turntable 38 illustrated in FIG. 1, the stop member 42 is located adjacent a cramping member 54 which is characterized by a flat surface and an arcuate opposite surface. The cramping member 54 is rotatable upon a pin 56 which is threadably mounted at its lower extremity within a sleeve 58 welded within an opening of the turntable 38, as best illustrated in FIG.

' 5. The upper extremity of the pin 56 threadably mounts a nut 58 by means of which the cramping member 54 is secured in a selected one of its rotated positions.

A vertically-oriented bending head pin 60 located at the center of the turntable 38 is threadably mounted at its lower end within a complementally threaded opening in the upper end of a shaft 62, as best seen in FIG. 5. An acme thread is used for strength, which is also the case with the threaded mounting of the pin 56 to the work table 36.

The pin 60 constitutes another stop against which the reinforcing bar 30 is deformed during a bending operation. As illustrated in FIGS. 2 and 3, the pin 60 is adapted to aid in bending a bar 30 of one size, and vertically, slidably accommodates a sleeve 64 to permit bending of larger sizes of reinforcing bar. Various outer diameters of sleeve 64 can be used for this purpose, as will be apparent.

Another stop is illustrated to the left of the stop member 42, as seen in FIGS. 1 through 3, and comprises a vertically-oriented pin 66 which is mounted to the work table 36 in a manner substantially identical to the mounting of the pin 60 to the turntable 38. That is, the pin 66 includes a lower extremity (not shown) which is threaded within a hardened sleeve (not shown) rigidly carried by the work table 36. In addition, the pin 66 vertically slid ably carries a large diameter sleeve 68 so that the pin and sleeve combination are adapted for the forming of various degrees of bend in various sizes of reinforcing bar 30, as will be apparent to those skilled in the art. In this regard, the bending operations possible with the stop member 42, cramping member 54, and

pins

60 and 66 are relatively well known and, therefore, will not be described in detail. Thus, in FIG. 2, a smaller size of reinforcing bar 30 can be formed by the

members

42 and 54 in the positions illustrated, while in FIG. 3 the cramping member 54 is fixed in a new position, the stop member 42 is retracted somewhat, and the sleeve 68 slipped over the pin 66 to bend the larger size bar shown.

The bar 30 is formed into the configuration illustrated in dash-dot outline by rotating the turntable 38 in a forward or clockwise direction, in which case the cramping member 54 wipes the bar 30 around the pin 60. Obviously, a reverse bend can be provided in the bar 30 by positioning the components of the apparatus so that the bar is deformed around the pin 60 during a counterclockwise or reverse rotation of the turntable 38.

The turntable 38 is welded to and is therefore supported by the upper end of the shaft 62. The shaft 62 is rotatably supported at its base by a bearing 70 which is secured to the frame base 32, and is rotatably supported just above its midportion by another bearing 72 which is fixed to a horizontally-oriented shelf 74. The shelf 74 forms a part of the frame 12 and is Welded at its edges to the adjacent frame walls 34.

The shaft 62 mounts a circular control plate or disc 76 which is adjustably fixed to the shaft 62 just below the shelf 74. The position of the disk 76 relative to the turntable 38 may be adjusted by operation of a usual set screw 78, as will be apparent.

The disc 76 mounts a cam 80 at its perimeter, the perimetrical position of the cam 80 being adjustable by loosening a set screw 82 which clamps the cam to the disc periphery, and sliding the cam 80 about the periphery of the disc 76 to the desired position. The bend switch 26 is suspended from the frame 12 in any suitable manner to project its switch arm into position adjacent the periphery of the disc 76 so that the contacts of the bend switch 26 are opened upon engagement of the switch with the cam 80.

The shaft 62 is keyed at its upper extremity to the bull gear 22 so that rotation of the bull gear will rotate the turntable 38. The bull gear 22, in turn, is engaged by the pinion gear 20 which is keyed to the upper extremity of a vertically-oriented pinion shaft 82. The shaft 82 is rotatably supported adjacent its upper extremity by a bearing 84 secured to the frame shelf 74, and at its base by a bearing 86 secured to the frame base 32.

A driven sprocket 88 is keyed to the pinion shaft 82 and is rotated by a drive chain 90 driven by a drive sprocket 92 which is secured to the output shaft of the speed reducer 18. This same output shaft mounts a flexible cable 94 which, as will be seen, is mechanically coupled to the control unit'28.

Although the particular drive for rotating the turntable 38, the disc 76 and its cam 80, and the flexible cable 94 is not critical to the present invention, it is a preferred system since it provides a variety of speeds which adapt the apparatus 10 to the bending of a variety of sizes and types of reinforcing bar.

The rnotor 14 is preferably a three-phase, 60 cycle, 208 volt motor which is internally geared to provide an output in the range of 350 rpm. under the control of a conventional motor controller or the like. It is characterized by an electrically operated integral brake which operates when the motor is de-energized. The motor controller is adapted to apply power to the motor 14 in a manner well known to those skilled in the art to effect either forward or reverse rotation of the motor. Forward rotation occurs upon energization of a forward coil 96, while reverse rotation is initiated upon energization of a reverse coil 98, as schematically shown in FIG. 8. Forward rotation causes corresponding forward rotation of the turntable 38, i.e. in a clockwise direction. Reverse rotation causes counterclockwise or reverse rotation of the turntable 38.

The transmission 16 coupled to the motor 14 is preferably a three-speed manually operated transmission type adapted to provide three input to output ratios, such as 1:85 to 1, 3:12 to 1, and 1 to 1. This is further reduced by the speed reducer 18, the

sprockets

88 and 92, and the bull gear 22 so that the revolutions per minute of the turntable become approximately 14, 8, and 2, which has been found to be satisfactory for bending the commonlyused sizes and types of reinforcing bar.

As previously indicated, the control unit 28 can be programmed to operate the bending apparatus 10 to form a succession of forward bends, a succession of reverse bends, or a sequence of up to three successive bends, each bend being of a predetermined degree. The bends are precisely repeatable since the turntable action is automatically terminated, as will be seen.

The control unit 28 includes a plurality of interval timers or delay counters 11, 102, 104, and 106. Such counters are available in a variety of types of styles and form no part of the present invention, other than in combination with the other components of the apparatus 10. A suitable form of counter is Type 307B Atcotrol, sold by Automatic Timing & Controls, Inc., of King of Prussia, Pa.

When energized, such a counter is operative to close a circuit to operate a motor or the like and, after a preset number of revolutions has occurred, as determined by adjustment of a counter dial 108, FIG. 6, the circuit is broken. Typical operation of each counter will become apparent from the following description of the circuitry and operation of the bending apparatus 10.

A length of reinforcing bar 30 is placed upon the work table 36 of the apparatus in the manner illustrated in FIG. 2. The selected counter of the control unit 28 is then preset for a single forward bend of 90 degrees, for example, the dial 108 being rotated until a 90 degree indication is shown. Such rotation has the effect of setting the counter so that, upon closure of its internal contacts, the contacts will automatically reopen when that number of revolutions of the flexible cable 94 has occurred which will amount to a 90 degree rotation of the turntable 38. That is, rotation of the cable 94 is proportionate to that of the turntable 38 so that a 90 degree rotation of the turntable 38 can be translated into a particular number of rotations of the cable 94, and this in turn is sensed by the mechanisms of the respective counters 100, 10-2, 104 and 106.

SINGLE FORWARD BEND Referring now particularly to FIG. 8, the control unit 28 includes a function switch 110 having four ganged switch arms 112, 114, 116, and 118 which are each movable over a contact set 120 comprising

contacts

100a, 102a, 104a, 106a, and 122. The first four of these contacts correspond to the four

counters

100, 102, 104, and 106.

The function switch 110 is set with its four switch arms in engagement with the contacts 100a to thereby use counter 100 for the bending of the single 90 degree forward bend.

Next, a locking drive switch is placed in its OFF position, as illustrated in FIG. 8, which has the effect of enabling a foot-operated switch 126 to effect return movement of the turntable 38 automatically upon release of the foot switch 126. The switch 126 is biased toward an open circuit position, the closed circuit position thereof being illustrated in FIG. 8.

A JOG switch 128 is also set in its OFF position, as shown in FIG. 8, by manually moving its pair of switch arms 130 and 132 into engagement with adjacent contacts 134 and 136, respectively.

A normally closed emergency switch 138 is left closed for normal operation of the bending apparatus 10. When moved to its open position, power to the apparatus 10 is cut off to instantly stop all operation.

Initiation of the single bend of the reinforcing bar 30 is effected by pressing the foot switch 126 to close the circuit and apply power to the counter 100 to operate the motor 14. More particularly, a three-phase 220 volt power source 140 is stepped down by a transformer 142 to provide 110 volt power to the circuit of FIG. 8. Three-phase power is applied to a conventional magneticallyoperated motor controller 144 associated with the motor 14. The three outputs of the motor 14 are illustrated diagrammatically and correspond to the outputs causing rotation of the turntable 38, rotation of the control disc 76, and rotation of the mechanisms (not shown) of the counters. Energization of the forward coil 96 causes the reversing mechanism 144 to apply three-phase 220 volt power to the motor 14 in a manner which will cause forward rotation of the motor and consequent clockwise or forward rotation of the turntable 38.

Upon movement of the turntable 38 in a clockwise direction, the switch 26 is moved to the closed position illustrated, which applies power from the A side of the line, through the switch arm 132, through the switch 126, through the reversing coil 98, through the switch arm 112 to the B side of the line. However, energization of the reverse coil 98 is not effective to cause reversal of the direction of rotation of the motor 14 because the reversing mechanism 144, as is well known to those skilled in the art, is characterized by a mechanical interlock which precludes operation of the motor 14 in a reverse direction until the coil 96 is de-energized.

Simultaneously with rotation of the control disc 76, the mechanism of the counter 100 is rotated by means of the flexible cable 94. Upon rotation of this mechanism a predetermined number of revolutions, as preset by adjustment of the dial 108 of the counter 100, an internal switch 150 of the counter 100 is opened to break the circuit to the forward coil 96. The energized reversing coil 98 is now free to operate the mechanism 144 to apply power to the motor 14 in a manner effecting reverse rotation of the motor. The motor 14 then rotates the turntable 38 in a reverse direction until the switch 26 engages the cam 80, opening the contacts.

It will be noted that during the forward portion of this sequence, the control power was applied through the foot switch 126, and had the switch 126 been released prior to reversal of the motor 14, the motor would have been reversed by the action of releasing the foot switch.

SINGLE BEND WITH LATCHING Assuming that the locking drive switch 124 is in its ON position, actuation of the foot switch 126 powers a relay through a set of contacts on the bend switch 26, which close when the bend switch 26 is released. Holding the foot switch 126 down or closed until the bend switch 26 is released by rotation of the turntable 38 allows the locking relay to activate and hold power on when the foot switch 26 is released. The sequence is identical to the Single Bend operation until the turntable 38 returns, and the bend switch is reactuated by the cam and releases the self-powering contacts of the locking relay.

When the 106 switch is in its ON position, all contacts are removed from the circuitry, including the automatic return, with the exception of the foot switch 126. When the foot switch 126 is actuated the turntable 38 will run in a forward direction and stop when the foot switch 126 is released. The JOG switch must be returned to its OFF position to run the turntable 38 back to its initial position.

SEQUENCE BENDINGDOUBLE BENDS Placing the function switch 110 in the AUTOMATIC position connects the rotary stepping switch and the double-triple switch into the forward control circuit. Actuating the momentary RESET switch will insure that the stepping relay is in the number one position. With the double-triple switch set in its double position, the outputs of the stepping switch are connected ultimately to the counters and 102. Depressing the foot switch 126 actuates the counter 100 and the apparatus 10 goes through the same sequence as just described under the heading Single Bend.

At the close of the cycle, the rotary stepping switch is latched to its second position, and connects counter 102 into the circuit. After another bending operation, the rotary stepping switch moves to its position three and reconnects to the counter 100. This alternating sequence continues for a total of six cycles then through deck 1 of the rotary stepping switch and its interrupting switch, the rotary stepping switch is rapidly cycled back to the first position. The operation can be repeated indefinitely.

SEQUENCE BENDINGTRIPLE BENDS With the movement of the double-triple switch to the triple position, and all other switches being in the same positions as in the double bending mode, the operation changes only by the inclusion of the third counter 104 in the cycle on every third bend.

REVERSE When the function switch is placed in its reverse position, the reverse bend counter 106 is engaged, and the forward and reverse motor control coils 96 and 98 are interchanged in function. The sequence of control function is the same as described under the heading Single Bend except that the directions are reversed.

7 EMERGENCY OFF SWITCH The emergency off switch 138 is connected in the output of the control power transformer and operating removes all control power. This stops the apparatus 10 in any portion of a cycle. When the emergency switch 138 is released, the turntable 38 will return to its initial position.

From the foregoing, it will be apparent that there has been provided a bending apparatus 10 which is adapted to repetitively form precision bends, each of which is precisely controlled in the degree of bend. Moreover, the sequence of bends may be repetitive of the same bend, or a sequence of up to three different bends may be formed in the same length of reinforcing bar. The bending operation is semi-automatic, and requires only that the counters be preset, the proper adjustment and selection be made of the pin 60, sleeve 68, cramping member 54, and stop member 42, and the reinforcing bar be advanced by the operator as each bend is made.

Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention or the scope of the following claims.

What is claimed is:

1. Bending apparatus for semi-automatically forming successive bends of predetermined degree in a length of reinforcing bar or the like, said apparatus comprising:

a frame;

a turntable rotatabl carried by said frame and adapted to support a reinforcing bar;

drive means coupled to said turntable and operable for rotating said turntable, said drive means being adapted for connection to a source of electrical energy, and including a motor controller having first means energizable to rotate said turntable in a forward direction, and second means energizable to rotate said turntable in a reverse direction upon de-energization of said first means;

stop means on said frame and on said turntable for bending said reinforcing bar upon rotation of said turntable;

and a control unit coupled to and operable by said drive means and including a plurality of electrically coupled delay counters, each said delay counter having circuit means electrically coupled to said first means for rotating said turntable in said forward direction, said delay counter being actuatable after a predetermined interval of operation of said control unit by said drive means, as predetermined by presettable counter means associated with each delay counter, to decouple said circuit means to deenergize said first means whereby said second means effects rotation of said turntable in said reverse direction, said control unit further including switching means for successively actuating said delay counters to successively energize said first means for successive intervals to achieve said successive bends in said reinforcing bar.

2. Bending apparatus according to claim 1 and including switch means in circuit with said motor controller and having portions on said drive means and on said frame engageable in a starting position of forward rotation of said turntable to actuate said first means to operate said drive means, and re-engageable after reverse rotation of said turntable to de-energize said second means.

3. Bending apparatus according to claim 1 and including foot switch means in circuit with said motor controller and foot-operated in one direction to energize said first means to operate said drive means and rotate said turntable in a forward direction, said foot switch means being foot operable in an opposite direction of rotation of said turntable to de-energize said first means whereby said second means is energized for rotating said turntable in a reverse direction.

4. Bending apparatus according to ciaim 3 and including holding means in circuit with said foot switch means and operative to maintain the circuit to said means closed despite release of said foot switch.

5. Bending apparatus according to claim 3 and including jog control means in circuit with said first means and said motor controller and operative in one position to interrupt said circuit whereby said foot switch means is operative only to energize said first means for rotating said turntable in one direction.

6. Bending apparatus according to claim 1 wherein said switching means of said control unit includes a sequencing means for successivel connecting said plurality of delay counters in circuit with said first means.

7. Bending apparatus according to claim 1 and including function switch means in circuit with said control unit and said motor controiler, said function switch means being operative to eifectively reverse the circuit connections to said first means and said second means whereby actuation of one of said delay counters effects rotation of said turntable in said reverse direction.

8. Bending apparatus according to claim 1 and including normally closed emergency switch means in the circuit of said motor controller and a source of power and operative to open said circuit whereby operation of said drive means is immediately terminated.

9. Bending apparatus for semi-automatically forming successive bends of predetermined degree in a length of reinforcing bar or the like, said apparatus comprising:

a frame;

a turntable rotatably carried by said frame and adapted to support a reinforcing bar;

drive means coupled to said turntable and actuable for rotating said turntable in first one direction and then in the opposite direction;

stop means on said frame and on said turntabie for bending said reinforcing bar upon rotation of said turntable;

and a control unit including counter means coupled to said drive means for registering the rotated position of said turntable, said control unit further including a plurality of setting means, each presettable to register a desired rotated position of said turntable, said counter means being operable upon coincidence of said rotated positions as registered by said counter means and as registered by one of said setting means to halt actuation of said drive means for rotation of said turntable in one direction and to enable actuation of said drive means for rotation of said turntable in the opposite direction, said counter means being successively operable by successive ones of said plurality of setting means for initiating successive actuations of said drive means to provide said successive bends in said reinforcing bar.

10. Bending apparatus according to claim 9 and including limit switch means in circuit with said drive means and having portions on said drive means and on said frame engaged in the starting position of said turntable, disengaged on rotation of said turntable in one direction, and re-engageable subsequent rotation of said turntable in the opposite direction to render said drive means inoperative.

References Cited UNITED STATES PATENTS 3,145,746 8/1964 Hill 72-22 3,192,750 7/ 1965 Richardson 72-22 3,299,681 l/ 1967 Hautau T 72-7 CHARLES W. LANHAM, Primary Examiner M. J. KEENAN, Assistant Examiner