US3766764A

US3766764A - Automatic pipe bender

Info

Publication number: US3766764A
Application number: US00187099A
Authority: US
Inventors: B Ross; J Limon
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-10-06
Filing date: 1971-10-06
Publication date: 1973-10-23
Anticipated expiration: 1990-10-23

Abstract

A system for automating a pipe bender of the type having a bending ram movable with a forward stroke towards back shoes for holding a pipe to be bent including a plurality of depth-of-bend dials for programming the depth required for sequential bends, a sequencing circuit for sequentially operating the depth-of-bend dials, a detector for determining the position of the bending ram during the forward stroke and a control circuit for comparing the position of the bending ram with the setting of the depth-of-bend dials in order to control the bending ram to stop the forward stroke after a desired bend has been formed in the pipe.

Description

United States Patent 1191 Ross et al.

[ AUTOMATIC PIPE BENDER [75] Inventors: Bernard D. Ross, 2710 Emmick St.,

. Toledo; Jose P. Limon, 209 Beech St., Rossford, both of Ohio [731 Assignee: said Ross by said Limon 22 Filed: Oct. 6, 1971 [2]] Appl. No.: 187,099

[ 1 Oct. 23, 1973 Primary ExaminerCharles W. Lanham Assistant Examiner-M. J. Keenan Att0rneyLeonard W. Sherman [57] ABSTRACT A system for automating a pipe bender of the type having a bending ram movable with a forward stroke towards back shoes for holding a pipe to be bent including a plurality of depth-of-bend dials for programming the depth required for sequential bends, a sequencing circuit for sequentially operating the depthof-bend dials, a detector for determining the position of the bending ram during the forward stroke and a control circuit for comparing the position of the bending ram with the setting of the depth-of-bend dials in order to control the bending-ram to stop the forward stroke after a desired bend has been formed in the pipe.

8 Claims, 7 Drawing Figures AUTOMATIC PIPE BENDER BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention pertains to automatic pipe benders and more particularly to such pipe benders which may be programmed to automatically effect a predetermined sequence of bends in a pipe in accordance with a set program.

2. Discussion of the Prior Art In order to stock pipes for use with various pieces of equipment and for packing applications, it is normally necessary to keep on hand a number of pipes thereby requiring great storage area and further requiring a large investment in inventory, which inventory investment is desirably reduced to a minimum.

This problem is particularly acute for those establishments which provide tail pipes for automobiles and other vehicles in that the tail pipes for various makes and models are different. That is, the bends in the various tail pipes are different and, therefore, require a great amount of stock to be maintained. The term tail size includes exhaust pipes and connector pipes as well as tail pipes utilized in exhaust systems; While storing tail pipes for more popular vehicles may be feasible due to the quantity sold, this is not necessarily the case for those models which are not so popular such as specialty and foreign automobiles.

It is important that an establishment specializing in the provision of mufflers and tail pipes have on hand the material to replace a customers tail pipe or muffler while he waits; and thus, it will be appreciated that investment inventory is extremely high. Of course, those establishments which do not specialize in the replacement of tail pipes and'mufflers are economically precluded from providing these services in that the investment inventory is extremely high and out of proportion to the amount of business generated.

In the past pipe benders have been provided in order to permit the stock of only straight pieces of'pipe which may be cut to a required length and selectively bent in accordance with the required configuration of the tail pipe to be installed. However, such pipe benders must be manually operated in accordance with a program or schedule provided according to the make of the-vehicle, and'the final bent tailpipe issubject to inaccuratebends due to normal human error. Furthermore, a skilled technician is required to make such bends thereby raising labor costs.

. Attempts to provide, automatic pipe benders have thus far not been economically and technologically acceptable in that such automatic pipe benders have either been extremely complex thereby increasing equipment costs and requiring training of an operator or such systems have not provided accurate bends and have not provided the flexibility required in such syspensively produced, is not complex, does not require skill in operation and is compatible with conventional type pipe benders in order to permit normal operation thereof.

The present invention is generally characterized in a system for automating a pipe bender of the type having a bending ram movable with the forward stroke toward back shoes for holding a pipe to be bent including a plurality of depth-of-bend adjustment means, sequencing means connected with the depth-of-bend adjustment and operable in response to bend commence means to sequentially operate consecutive ones of the depth-of-bend adjustment means, detector means providing a signal corresponding to the position of the bending ram during the forward stroke, and control means for comparing the position of the bending ram with the setting of a corresponding depth-of-bend adjustment means to control the stopping of the forward stroke of the bending ram when the position of the bending ram corresponds with the setting of the depthof-bend adjustment means.

Another object ofthe present invention is to provide an automatic system for use with a pipe b'enderthat does not inhibit manual operation of the pipe bender.

A further object of the present invention is to provide an automated system for use with pipe benders that automatically controls the forward-stroke of a bending ram for sequential bends. I

The present invention has another object in that an automated'system for use with a pipe bender may be simply programmed to automatically effect predeter mined sequential bends in a pipe, count the bends to commence the cycle of sequential bends for another pipe and count the number of completed bent pipes.

Yet another object of the present invention is to provide apparatus for supporting and guiding movement of a pipe to be bent with an automated pipe bender.

Some of the advantages of the present invention over the prior art are that the automating system of the pres ent invention may be permanently connected with a conventional pipe bender without inhibiting normal operation thereof in order to permit manual operation of the pipe bender without removing the system, thesys- ,tem can be programmed to provide any depth or degree of bend between 0 and 180, any bend within the programmed sequence of operation for the system may be by-passed o'r overridden during operation without nance and repair.

tems to permit easy transfer from automatic to manual modes of operation or to permit precise bend selection. Furthermore, prior art automatic pipe benders have the disadvantages of inhibiting normal manual operation of a conventional pipe bender after connection thereto, of limiting the number of bends which can be made at any specific angle and do not permit manual override of the automatic mode when a bend is in process.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an automatic pipe bender that may be inexadversely affecting the continuing sequence, any number of bends maybe formed at the same depth, and the system is provided in'a single unit to facilitate mainte- Other objects and advantages of the present invention will become apparent from the'follow'ing description of the preferred embodiment taken in conjunction with the accompanying drawings.

. BRIEF DESCRIPTION OF THE DRAWINGS FIG.-1 is a perspective view of a panel housing the au-" an indexing assembly of FIG. 1. I

FIG. 4 is a broken perspective of the detector of FIG. 1 for determining the position of the bending ram.

FIGS. 5a, 5b and 5c are schematic diagrams of the automating system of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The pipe bender automating system of the present invention is illustrated in FIG. 1 as utilized with a conventional pipe bender, such as models 1700 and 2007 manufactured by I-Iuth Manufacturing Corporation. As is conventional, the pipe bender basically includes a hydraulically operated bending ram movable during a forward stroke toward a pair of

back shoes

12 and 14 which are mounted to pivot under the force from the stroke of the bending ram. The pipe to be bent is received in arcuate channels formed in the head of the bending ram and the back shoes such that the pipe may be firmly held by the back shoes during the bending operation. No further detailed description is provided rel ative to the structure and operation of such pipe benders since they are well known; and, it will be appreciated that the automating system of the present invention may be utilized with any conventional pipe bender.

The automating system of the present invention is supported within a housing 18 having a panel 20 angularly disposed at the top thereof. Ten depth-of-

bend adjustment dials

22, 24, 26, 28, 30, 32, 34, 36, 38 and 40 are disposed in two rows at the top of panel 20, and each of the depth-of-bend dials includes a knob attached to a pointer that may be moved over a scale from 0 to 180 such that by rotation of the knob, the pointer may be set on the specific angle of bend to be effected. A bend selector 42 is disposed in a lower corner of panel 20 and includes a knob with a pointer which may be set to any number of desired bends to be made in sequence. For exemplary purposes, 10 positions are shown for the bend selector 42; however, it

will be appreciated that any number of sequential bends may be made in a pipe in accordance with the present invention by increasing the number depth-ofbend dials and correspondingly increasing the number of positions for the pointer of bend selector 42.

A pipe selector 44 is disposed on the face of panel 20 in the lower right hand corner and includes'a knob movable to set a pointer at a position corresponding to the number of pipes to be bent with the sequential program set by the depth-of-bend dials and the bend selector. That is, the numberof pipes to be bent with the sequential bends programmed into the vdepth-of-bend dials and the bend selector is set by turning the knob of pipe selector 44 such that the sequence of bends may be repeated for consecutivepipes duplicating the bends thereof.

A reset switch 46 in the form of a push button combined with a red light RL is positioned on panel 20 and may be depressed in order to provide manual reset of the various programming dials and selectors on the panel, and a cycle start switch 48 is provided on the panel in order to initiate a bending cycle. A cycle control switch 50 is disposed between the reset and cycle switches and includes a knob for setting the cycle operation to provide either manual operation of the pipe bender in which case an amber light 52 will be energized or automatic operation in which case a green light 53 will be energized. On the face of the housing 18 are provided an on-off power switch 54 which, when placed on the on condition, will energize a red light 56, a start switch 58 for the hydraulic pump within the pipe bender and a stop switch 60 for the hydraulic pump. A foot switch 62 is disposed at the bottom of the housing 18 in order to permit foot control to start a bending cycle in the same manner as cycle start switch 48.

An elongated guide bench 64 is supported on stands 65 and 66 in alignment with the arcuate channels in

back shoes

12 and 14 in order to support and guide a straight length of pipe P to be bent as is illustrated in FIGS. 1 and 2. Bench 64 includes an elongated horizontal base plate 68 secured to a vertical member 70 which has a plurality of longitudinal slots 72 extending therethrough. An elongated measuring ledge 74 is secured to member 70 on the opposite side from base plate 68 and is positioned between the level of base plate 68 and slots 72. Ledge 74 carries a scale 75 thereon indicating the distance from the bending point of the pipe bender, which scale 75 may be permanently formed on the ledge or may be removably carried thereby. A plurality of guide pins 76 are slidably disposed in slots 72, and each of guide pins 76 is adapted to be secured in place by means ofa flange 77, a washer 78 and a nut 79 engaging a threaded end 80 of each pin. The number of guide pins required is determined by the total number of bends capable of being formed in a single sequence.

A pipe support and indexing assembly for engagement with a pipe P to be bent and cooperation with guide bench 64 is illustrated in FIGS. 1 and 3 and includes a clamp bar 82 having an externally threaded post 84 at one end thereof adapted to engage a plug 86 for attachment to the trailing end of a pipe P to be bent. Clamp bar 82 includes a large diameter rod 87 having a dowel 88 extending therethrough adjacent post 84, and an externally threaded post 89 extends from the other end of rod 87. A key 90 is formed at an annular shoulder 91 adjoining post 89 and rod 87 and cooperates with a keyway 92 formed in a central bore 93 of an indexing disc 94.

Indexing disc 94 is received on post 89 with key 90 mating with keyway 92 and is held in place by an internally threaded sleeve 95 which is screwed onto post 89 and has a dowel 96 extending therethrough to provide a tightening grip. Indexing disc 94 carries markings indicating the sequential bends to be formed in a pipe including sequential numbers for the bends, distancesbement with the arcuate channels in the back shoes of the pipe bender. v g

The parts of guide bench .64 are preferably made of a suitable metal with base plate 68, vertical member 70 and ledge 74 secured in any conventional manner such as by welding or bolting. Clamp bar 82 and sleeve 95 are, similarly, desirably made of a suitable'metal', and plug 86 and indexing disc 94 are desirably made of nylon. Plug 86 has a frusto-conical configuration in order to provide afriction fit in the open trailing end of the pipe P to be bent, and an internally threaded bore 97 is centrally disposed in plug 86 to receive post 84 of clamp bar 82. i

A detector for determining the position of bending ram 10 is illustrated in FIGS. 1 and 4 and includes an arcuate resistor 98 having a'tap 99 movable thereac'ross with pivotal movement of back shoe 12 during the forward stroke of bending ram 10. Wires A, B and C are connected to the ends of variable resistor 98 and top 99, respectively, in order to provide an electrical signal corresponding to changing resistance as the bending ram is moved.

The automating system of the present invention is schematically illustrated in FIGS. 5a, 5b and 5c and includes a motor M for operating a hydraulic pump and which is connected to an AC source 100 through normally open contacts MR1 and MR2. The AC signal from source 100 is supplied to the primary winding of a transformer 102 through the on-off power switch 54. Also connected to receive the AC signal from source 100 are a forward stroke control solenoid FS and a reverse stroke control solenoid RS through normally open contacts CR3-1 and CR4-1, respectively. A forward foot switch FF S and a reverse foot switch RF S are connected in parallel with normally open contacts CR3-1 and CR4-1, respectively, in order to permit normal manual operation of the pipe bender. Switches FPS and RFS and solenoids FS and RS are provided on conventional pipe benders in order to operate valves controlling hydraulic force to the bending ram such that when solenoid FS is energized, the bending ram is provided with a forward stroke and when solenoid RS is energized the bending ram is provided with a reverse stroke.

The secondary winding of transformer 102 is connected at one terminal to a bus 104 and at another terminal through normally closed hydraulic pump stop switch 60 and an emergency stop switch 106, which is disposed within easy reach of an operator on either panel or the-pipe bender, to a bus 108. The lamp 56 indicating that power is being transmitted to the system is connected across the secondary winding of transformer 102 such that when the transformer receives current to provide a supplyv voltage to the circuit, the lamp 56 is energized. The hydraulic pump start switch 58 is connected in series with a motor control relay MR between buses 104 and'l0'8, and a-pair of normally open holding contacts --MR3 are connected in parallel in FIG. 5a,'a relay CR1 will be adapted to be connected between

buses

104 and 108 and in its manual state,.

mally open contacts CR3-3.

amber lamp 52 is adapted to be connected between

buses

104 and 108. Connected in parallel with relay with relay CR1 through a pair'of normally .open con tacts CR2-l are reset switch46 and a reset relay CR2 in series and the red reset lamp RL forming-the buttontype depression actuator for switch 46. The junction of switch 58, normally-opencontacts MR3 and relay" MR is connected 'with a bus 112 through a pair of normally open contacts-CRl-l, and relay CR2 is connected between bus 104 and bus-112 through a stepping switch SS1 which has an armature controlled by astepping relay SC2 and has its tenth contact connected with reset switch 46 and lamp L.

An interlocking relay CR3 is connected in series with normally closed contacts CR4-2, cycle-start switch 48 and normally closed contacts CR2-2 and CR1 l-l across

buses

104 and 112, and normally open contacts CR3-2 and CR7-l are connected in series across foot cycle-start switch 62 which is connected in parallel As illustrated in FIG. Sb, a stepping relay SCl, which is operative to count completed bends and provide sequential control of the depth-of-bend dials, is connected across

buses

104 and 112 through normally open contacts CR8-1, normally closed contacts SCI-1, normally closed contacts SC 1-2 and a diode D1 and a resistorRl. A holding capacitor C1 is connected in parallel across stepping relay SCl. Lead 116 is connected with the junction of normally closed contacts SCI-1 and SCI-2 through normally closed contacts CR6-1. A stop relay CR6 is connected between

buses

104 and 112 through normally closed contacts CR8-2 and CR4-2 and the parallel combination of normally open contacts SCI-3 and CR6-2. A pulsing relay CR7 is connected between bus 104 and lead 114 by means of a diode D2 and a resistor R2.

A stepping switch SS2, which has an armature controlled by stepping relay SCI, is connected between

buses

104 and 112 through a plurality of lamps L1 through L10, and a stepping switch SS3, which'has an armature controlled by stepping relay SCI, is connected-with bus 112 through normally closed-contacts CR5-2. The contacts of stepping switch SS3 are each connected through a diode and a lead 118 to the junction between diode D2 and resistor R2. Each of the contacts of stepping switch SS3 is also connected with a corresponding contact of bend selector 42 which is connected through a reset relay CR8. to bus 104. Relay CR8 is, also connected to contacts CR'5-2 through normally closed contacts SCI-4 and the parallel combination-of normally open contacts CR8-3 and reset switch Stepping relay SC2, which has a holding capacitor C3 in parallel therewith, receives the output from bend selector 42 through normally-closed contacts CR9-1 and;

SC2-1, diode D3 and resistor R3. The junction between contacts CR9-1 and SC2-1 is connectedto bus 112 through normally open contacts CR10-1 and normallyclosed contacts SC2-2..A relay CR9 is connected between buses 1 04 and 112 through normally closed contacts CR4-3 and the parallel combination of normally open co tacts CR9-2 and SC2-3. A stepping switch SS4 has an a mature controlled by stepping 'relay SC2 and is conne:cted to bus 112 through normally'closed com; .tac'ts' CR5-3 and SC2-4, and each of the contacts of stepping switch SS4, is connected'to a corresponding contact of pipe selector 44. The output of pipe selector 44 isconnected through a clear relay CR10 to bus 104, and. stepping switch SS4 and pipe selector 44 are bypassed'by a pair of normally open holding contacts CR10-2.

A stepping switch SS5 is connected across

buses

104 and 112 and has an armature controlled by stepping relay SCI. The contacts of stepping switch SS5 are connected to bus 104 through windings B1 through B10 BC10, respectively. The sets of contacts BCl through BC10 are connected in series with depth-of-bend dials 22 through 40, respectively, as illustrated in FIG. 4c. A control relay CR11 is connected across

buses

104 and 112 through a diode D4 and an SCR 120. Also connected between

buses

104 and 112 is the primary winding 122 of a transformer 124 that has its secondary winding 126 connected across a voltage divider network including variable resistor 98, one of the depthof-bend dials and a resistor R4. A capacitor C3 and a resistor R5 are connected in parallel with resistor R6, and the gate of SCR 120 is connected through a resistor R6 such that the gate and cathode of the SCR are connected across the parallel combination of resistors R4 and R5 and capacitor C3. Wire A from variable resistor 98 is connected with secondary winding 126 through a resistor R7.

When it is desired to bend a straight length of pipe P to provide a specific configuration such as for use as a tail pipe for a sepcific make of automobile, an operator will select an indexing disc 94 having indicia thereon corresponding to the required configuration for the tail pipe. The indexing disc 94 is placed on clamp bar 82 with key 90 mating with keyway 92, and sleeve 95 is screwed onto post 89 to secure the indexing disc. Thus, indexing disc 94 is secured on the clamp bar 92 so as to be neither rotatably nor longitudinally movable.

Plug 86 is inserted in the open trailing end of the pipe P to be bent to provide a friction fit therewith such that the pipe and the plug move as a unit. Post 84 of clamp bar 82 is then screwed into bore 97 in plug 86 such that the pipe support and indexing assembly is securely mounted on the pipe to be bent. The pipe is then positioned with its leading edge adjacent the pipe bender within the arcuate channel provided by back shoe 14, and indexing disc 94 has its peripheral edge resting on base plate 68 such that the pipe P is linearly aligned with the arcuate channels in the back shoe. Guide pins 76 are then positioned within the slots 72 along member 70 corresponding to the distances between bends in the pipe P. The adjustment of the pins 76 is facilitated by their extension over the scale 75 carried on ledge 74, and the pins 76 extend sufficiently to permit alignment of indexing disc 92 therewith during the bending operation. With the guide pins so positioned, the operator merely moves the pipe P after each bend to align the indexing disc 94 with the next guide -pin which will provide the pipe with bends accurately spaced. The clamp bar 92 may be rotated by means of dowel 88 in accordance with the indicia on indexing disx 94 to properly rotate the pipev in accordance with the angle of the required bend.

In order to place the system in condition for operation power switch 54 is actuated to supply voltage to transformer 102, and hydraulic pump start switch 58 is depressed to energize relay MR which closes contacts MR1 and MR2 to start motor M and place the hydraulic pump in operating condition. Holding contacts MR3 are closed by energization of, relay MR; and, accordingly, relay MR is latched in its energized state. If the system is to be utilized in the automatic mode of operation, relay CR1 will be energized along with relay MR due to the position of switch 50. That is, the manualautomatic switch 50 is utilized to either permit the energization of relay CR1 and lamp 54 in the automatic mode or to permitthe energization of lamp 52 indicating that the system is in the manual mode of operation.

If the system is placed in the manual mode of operation, movement of bending ram 10 may be controlled by switches FPS and RFS as is conventional, and the automating system of the present invention in no way inhibits or adversely affects such manual operation.

If relay CR1 is energized to provide automatic operation, normally open contacts CR1-1 will be closed to energize the automating portion of the circuitry via

buses

112 and 104. In order to program the automating system of the present invention for the automatic mode of operation, the number of total bends to be formed in each pipe is set by proper positioning of bend selector 42 and the angle or depth-of-bend required during each bending operation is set by movement of dials 22 through 40. That is, if for example five bends were to be formed in the pipe P, the bend selector 42 would be set to five and the first five depth-of-bend dials 22, 24, 26, 28 and 30 would be set to the required angle for each consecutive bend. That is, dial 22 may be set such that the first bend is 10 and dials 24, 26, 28 and 30 may be similarly set to any desired angle, which may be the same or different from any of the other angles set in the dials. The number of pipes to be produced having this specific confirguation is determined and pipe selector 44 is set to represent the number of pipes to be bent.

The operator moves the pipe P to align the indexing disc 94 at a pre-selected position, as described above, and a bending cycle is initiated by depressing either of cycle-start switches 48 or 62. The depressing of the cyole-start switches energizes relay CR3 which closes contacts CR3-1 to energize lead 114, and with relay CR7 energized, contacts CR7-1 will be closed to latch relay CR3 in its energized state.

Relay CR5 is energized. at this time due to the closure of contacts CR7-2 and CR3-5, and stepping relay SC 1 is energized through the closing of contacts CR3-3 and lead 116 to move stepping switches SS2, SS3 and SS5 one step to accordingly energize lamp L1 to indicate that the first bend is in progress and to energize winding B1 which closes contacts BCl to connect the variable resistance controlled by dial 22 in circuit with the voltage dividing network including variable resistor 98. Thus, stepping relay SCl provides sequencing control for the automating system and permits counting .of bends by stepping switch SS2.

Relay CR6 is energized in response to the energizetion of stepping relay SC1 and is latched in this state by the closure of holding contacts CR6-2, and contacts CR6-l are opened to limit stepping relay SC1 to a single step.

At the beginning of the forward stroke of bending ram 10 the resistance presented by variable resistor 98 in the voltage divider network is high and the voltage across resistor R4 is not sufficient to trigger SCR 120. As the forward stroke of the bending ram continues, however, the resistance presented by variable resistor 98 decreases; and, when the voltage across resistor R4 reaches a sufficient value, SCR 120 will be triggered to energize relay CR1 1. It will be appreciated, of course,

that the movement of bending ram 10 is thus effectively controlled by the resistance provided by the setting of dial 22; and, accordingly, dial 22 is calibrated such that the movement of bending ram 10 provides a bend having a specific depth in accordance with the setting of the depth-of-bend dials.

Once relay CRll is energized, relay CR3 will be deenergized due to the opening of normally closed contacts CRll-l; and, thus, forward stroke solenoid FS will be deenergized to stop the forward stroke of the bending ram by the opening of contacts CR3-1. With relay CR3 deenergized, relay CR4 is energized through limit switch LS1 andcontacts CRS-l to initiate a return stroke of the bending ram by closing contacts CR4-1 and energizing reverse stroke solenoid RS.

Once the bending ram returns to its initial position limit switch LS1 will be momentarily opened in order to return the system to its cycle initiation state in order to permit the forming of a second bend.

The operator accordingly properly positions pipe P with respect to rotation and longitudinal movement for the second programmed bend and thereafter depresses one of the cycle-start switches 48 or 62 to initiate a second bending cycle as described above. As each bending operation is completed, stepping relay SCI will step switch SS2 to indicate by means of lamps Ll through L10 which bend is in progress, will step switch SS3 to count the number of completed bends and will step switch SS5 to sequentially energize the depth-of-bend dials such that the angle or depth of each bend is sequentially controlled by' the dials 22 through 40.

Once the programmed number of bends, as set in bend selector 42, is completed, connection will be provided between stepping switch SS2 and bend selector 42 to energize reset relay CR8 which is latched in its energized state by contacts CR8-3. With relay CR8 energized, stepping relay SCI will be energized through contacts CR8-1 to return stepping switches SS2, SS3 and SS5 to their initial states in order to permit a second pipe to be sequentially bent in the manner as described above.

Once a circuit is completed between stepping switch SS3 and bend selector 42, stepping relay SC2 is energized to step switches SS1 and SS4 one step. The energization of stepping relay SC2 energizes relay CR9 which islatched by holding contacts CR9-2 and opera tive to open contacts CR9-1 to assure that stepping relay SC2 is energized to provideonly a single step. Thus, after the bends have been completed in each pipe, stepping switch. SS4 will be moved one step'to count the number of pipes which have beencompleted; and once the number of completed pipesequals the number set in pipe selector 44, a circuit will be completed through stepping switch SS4 and pipe selector 44 to energizerelayCRlO whichis operativethrough closure of contact CRlO-l to drive stepping relay SC2 to return stepping switches SS1 and SS4 to their initial position. Thus, it will be seen that at the endof a completed operation, the automatic system of the present invention will be returned to its initial state to provide automatic bending operation for other pipes to be bent.

If at any time during the operation of the automating system of the present invention it is desired to, for any reason, manually control the forward stroke of the bending ram, the manual-automatic switch'50 may be placed in the manual position to dee'nergize the automating circuitry and permit control of the forward and reverse stroke solely by means of foot switches F F S and RFS, respectively. The manual override of the automating system is accomplished by moving switch after the light indicating the bend to be started is energized such that once the manual-automatic switch 50 is returned to its automatic position, the stepping switches will be positioned to permit the sequential bending operation to continue.

The automatic system may be reset at any time by depressing reset button 46 and energizing relay CR8 to return stepping switches SS2, SS3 and SS4 to their initial states. Once stepping switch SS1 has been rotated to its tenth position, relay CR2 will be energized to prevent further operation of the system until reset switch 46 is depressed.

From the above it can be seen that the automating system and apparatus of the present invention permits automatic operation of a pipe bender without inhibiting manual operation thereof, override of the automatic operation to permit manual bending within a programmed sequence, and setting of the desired number of bends and pipes to be bent to more fully automate operation. The apparatus for supporting and guiding a pipe to be bent facilitates movement of the pipe by an operator due to the relationship between the indexing disc and the guide bench as well as maintaining the pipe in a straight configuration prior to bending.

While the automating system of the present invention has been described above utilizing relay circuitry, it will be appreciated that any electrical or electronic circuitry could be utilized to provide the required operation within the scope of the present invention.

. Inasmuch as the present invention is subject to many variations, modifications and changes in detail, his intended that all matter described above or shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense.

What is claimed is: v

1. A system for automating a pipe bender of the type having a bending ram movable with a forwardstroke toward back shoes for holding a pipe to be bent, said system comprising a plurality of depth-of-bend adjustment means;

actuating means for starting and stopping the forward stroke of the bending ram; sequencing means connected with each of said depth-of-bend adjustment means; 1 t bend commence means operable to actuate said actuating means to start'the forwardstrokeof the -bending -ram and a to energize said-sequencing means to sequentially operate consecutive ones of said depth-of-bend adjustment means; detector means providinga signal corresponding to the position of the bending ram during the forward stroke;

control means for comparing the position of the bending ram with the setting of said operating one of said depth-of-bend adjustment means and controlling said actuation 'means to stop the forward stroke of the bending ram when the position of the bending ram corresponds with the settinggof said operating one of said depth-of-bend; adjustment means;

first countermeans responsive to said sequencing means to count the number of bends made by the forward strokes of the bending ram;

bend selector means adapted to be set to a predeterpre-determined number of bends set in said bend selector means;

second counter means responsive to said reset means to count the number of pipes having said predetermined number of bends formed therein;

pipe selector means adapted to be set to a predetermined number of pipes to be bent; and

clear means responsive to said pipe selector means and said second counter means to indicate the bending of said predetermined number of pipes when the number of pipes having said predetermined number of bends therein equals the predetermined number of pipes set in said pipe selector means.

2. A system for automating a pipe bender of the type having a bending ram movable with a forward stroke toward back shoes for holding a iipe to be bent, said system comprising a plurality of depth-of-ben'd adjustment means each including a variable resistor adjustable to present a resistance corresponding to the depth of a bend to be formed;

actuating means for starting and stopping the forward stroke of the bending ram;

sequencing means connected. with each of said depth-of-bend adjustment means;

bend commence means operable to actuate said actuating means to start the forward stroke of the bending ram and to energize said sequencing means to sequentially operate consecutive ones of said depth-of-bend adjustment means;

detector means providing a signal corresponding to the position of the bending ram during the forward stroke; and

control means for comparing the position of the bending ram with the setting of said operating one of said depth-of-bend adjustment means and controlling said actuation means to stop the forward stroke of the bending ram when the position of the bending ram corresponds with the setting of said operating one of said depth-of-bend adjustment means, said control means including resistance means having a resistance varying with movement of the bending ram,

said sequencing means including means for sequentially connecting said variable resistors in circuit with said resistance means to form a voltage divider, and said control means including means for sensing voltage across a portion of said voltage divider for controlling said actuating means to stop the forward stroke of the bending ram when the sensed voltage reaches a predetermined value.

3. The system as recited in claim 2 and further comprising counter means responsive to said sequencing means to count the number of bends made by the forward strokes of the bending ram.

4. The system as recited in claim 3 and further comprising bend selector means adapted to be set to a predetermined number of bends, and reset means responsive to said. bend selector means and said counter means to indicate the completion of bends in a pipe and to reset said counter means when the number of bends made by the forward strokes of the bending rarn equals the predetermined number of bends set in said bend selector means.

5. The system as recited in claim 4 and further comprising second counter means responsive to said reset means to count the number of pipes having said predetermined number of bends formed therein.

6. The system as recited in claim 5 and further comprising pipe selector means adapted to be set to a predetermined number of pipes to be bent, and clear means responsive to said pipe selector means and said counter means to indicate the bending of said predetermined number of pipes when the number of pipes having said predetermined number of bends therein equals the predetermined number of pipes set in said pipe selector means.

7. The system as recited in claim 2 wherein said resistance means includes an arcuate resistor disposed adjacent one of the back shoes, and a tap carried by said one of the back shoes and engaging said resistor.

8. The apparatus as recited in claim 2 wherein said control means includes a controlled rectifier having gate and cathode electrodes for sensing voltage across said portion of said voltage divider, said controlled rectifier being triggered when the sensed voltage reaches said predetermined value to operate said actuating means to stop the forward stroke of the bending ram.

Claims

1. A system for automating a pipe bender of the type having a bending ram movable with a forward stroke toward back shoes for holding a pipe to be bent, said system comprising a plurality of depth-of-bend adjustment means; actuating means for starting and stopping the forward stroke of the bending ram; sequencing means connected with each of said depth-of-bend adjustment means; bend commence means operable to actuate said actuating means to start the forward stroke of the bending ram and to energize said sequencing means to sequentially operate consecutive ones of said depth-of-bend adjustment means; detector means providing a signal corresponding to the position of the bending ram during the forward stroke; control means for comparing the position of the bending ram with the setting of said operating one of said depth-of-bend adjustment means and controlling said actuation means to stop the forward stroke of the bending ram when the position of the bending ram corresponds with the setting of said operating one of said depth-of-bend adjustment means; first counter means responsive to said sequencing means to count the number of bends made by the forward strokes of the bending ram; bend selector means adapted to be set to a predetermined number of bends; reset means responsive to said bend selector means and said first counter means to indicate the completion of bends in a pipe and to reset said first counter means when the number of bends made by the forward strokes of the bending ram equals the pre-determined number of bends set in said bend selector means; second counter means responsive to said reset means to count the number of pipes having said predetermined number of bends formed therein; pipe selector means adapted to be set to a predetermined number of pipes to be bent; and clear means responsive to said pipe selector means and said second counter means to indicate the bending of said predetermined number of pipes when The number of pipes having said predetermined number of bends therein equals the predetermined number of pipes set in said pipe selector means.

2. A system for automating a pipe bender of the type having a bending ram movable with a forward stroke toward back shoes for holding a pipe to be bent, said system comprising a plurality of depth-of-bend adjustment means each including a variable resistor adjustable to present a resistance corresponding to the depth of a bend to be formed; actuating means for starting and stopping the forward stroke of the bending ram; sequencing means connected with each of said depth-of-bend adjustment means; bend commence means operable to actuate said actuating means to start the forward stroke of the bending ram and to energize said sequencing means to sequentially operate consecutive ones of said depth-of-bend adjustment means; detector means providing a signal corresponding to the position of the bending ram during the forward stroke; and control means for comparing the position of the bending ram with the setting of said operating one of said depth-of-bend adjustment means and controlling said actuation means to stop the forward stroke of the bending ram when the position of the bending ram corresponds with the setting of said operating one of said depth-of-bend adjustment means, said control means including resistance means having a resistance varying with movement of the bending ram, said sequencing means including means for sequentially connecting said variable resistors in circuit with said resistance means to form a voltage divider, and said control means including means for sensing voltage across a portion of said voltage divider for controlling said actuating means to stop the forward stroke of the bending ram when the sensed voltage reaches a predetermined value.

4. The system as recited in claim 3 and further comprising bend selector means adapted to be set to a predetermined number of bends, and reset means responsive to said bend selector means and said counter means to indicate the completion of bends in a pipe and to reset said counter means when the number of bends made by the forward strokes of the bending ram equals the predetermined number of bends set in said bend selector means.