CA1170965A - Incremental bending method and apparatus - Google Patents
Incremental bending method and apparatusInfo
- Publication number
- CA1170965A CA1170965A CA000365216A CA365216A CA1170965A CA 1170965 A CA1170965 A CA 1170965A CA 000365216 A CA000365216 A CA 000365216A CA 365216 A CA365216 A CA 365216A CA 1170965 A CA1170965 A CA 1170965A
- Authority
- CA
- Canada
- Prior art keywords
- bend
- bending
- article
- incremental
- machine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D7/00—Bending rods, profiles, or tubes
- B21D7/02—Bending rods, profiles, or tubes over a stationary forming member; by use of a swinging forming member or abutment
- B21D7/024—Bending rods, profiles, or tubes over a stationary forming member; by use of a swinging forming member or abutment by a swinging forming member
Abstract
INCREMENTAL BENDING METHOD AND APPARATUS
Abstract of the Disclosure Small gauge metal tubing is bent into required configuration by a repeated bend-shift-bend method in which the tubing is advanced intermittently through a bend head which operates to put an incremental bend portion of controlled angular extent into the tubing.
The method determines the final configuration of the tubing as a function (i) of the number and/or angular extent of the incremental bend portions, and (ii) of the extent of translation of the tubing between successive incremental bend portions. The method also envisages rotation of the tubing for determining the plane of the incremental bends. A bending machine for performing the method comprises a powered carriage (3) movable within a channel track (38) under control of a motor (13) and carrying a lazy-tongs type clamping arrangement (8) which is rotatable by a motor (44) for axially rotating a clamped tube (1) being bent. The carriage (3) moves the clamped tubing intermittently and by controlled amounts through a bending head (4) which comprises a hydraulically operated die and former arrangement wherein the die and former are relatively movable to put an incremental bend portion into that part of the tubing which is engaged with the bending head. The bending, translating and rotating movements in the machine can be computer controlled.
Abstract of the Disclosure Small gauge metal tubing is bent into required configuration by a repeated bend-shift-bend method in which the tubing is advanced intermittently through a bend head which operates to put an incremental bend portion of controlled angular extent into the tubing.
The method determines the final configuration of the tubing as a function (i) of the number and/or angular extent of the incremental bend portions, and (ii) of the extent of translation of the tubing between successive incremental bend portions. The method also envisages rotation of the tubing for determining the plane of the incremental bends. A bending machine for performing the method comprises a powered carriage (3) movable within a channel track (38) under control of a motor (13) and carrying a lazy-tongs type clamping arrangement (8) which is rotatable by a motor (44) for axially rotating a clamped tube (1) being bent. The carriage (3) moves the clamped tubing intermittently and by controlled amounts through a bending head (4) which comprises a hydraulically operated die and former arrangement wherein the die and former are relatively movable to put an incremental bend portion into that part of the tubing which is engaged with the bending head. The bending, translating and rotating movements in the machine can be computer controlled.
Description
g6~5 INCREMENTAL BENDING METHOD AND APPARATUS
This invention relates to bending, in particular but not exclusively to bending metal tubes already nutted and flared such as automotive brake pipes.
There are many applications which make it desirable to have a machine capable of providing successive bends of different configuration in articles such as metal strip, wire, rod or tubing, without the necessity to adjust the machine between bends. One such application is in the manu-facture of automotive brake pipes where a complexity of bends may be required which varies from model to model.
Economic considerations make it preferable that a single machine should be capable of providing these complex curva-tures and also be readily adjustable to bend work-pieces to different formations.
At present brake tubes are bent by use of manual jigs employing concial formers which have grooves of vary-ing radii around which the tubes are bent. Such a bending operation is labour intensive and imprecise, and further-more the jigs are bulky.
An aspect of the invention is as follows:
A method of producing a bend in an article whichcomprises translating intermittently and by controlled amounts relative to a bending station a section of said article which section will provide said bend, and mean-while performing at said station a plurality of inter-mittent bending operations alternating with the transla-tions of the article relative to said station, whereby said bend is gradually generated and the configuration of said bend is determined (i) by the number of said operations and the angular deformation produced by each of said operations in said section and (ii) by the extent of translation between successive said operations.
Other aspects of the invention are as follows:
~17~ 5
This invention relates to bending, in particular but not exclusively to bending metal tubes already nutted and flared such as automotive brake pipes.
There are many applications which make it desirable to have a machine capable of providing successive bends of different configuration in articles such as metal strip, wire, rod or tubing, without the necessity to adjust the machine between bends. One such application is in the manu-facture of automotive brake pipes where a complexity of bends may be required which varies from model to model.
Economic considerations make it preferable that a single machine should be capable of providing these complex curva-tures and also be readily adjustable to bend work-pieces to different formations.
At present brake tubes are bent by use of manual jigs employing concial formers which have grooves of vary-ing radii around which the tubes are bent. Such a bending operation is labour intensive and imprecise, and further-more the jigs are bulky.
An aspect of the invention is as follows:
A method of producing a bend in an article whichcomprises translating intermittently and by controlled amounts relative to a bending station a section of said article which section will provide said bend, and mean-while performing at said station a plurality of inter-mittent bending operations alternating with the transla-tions of the article relative to said station, whereby said bend is gradually generated and the configuration of said bend is determined (i) by the number of said operations and the angular deformation produced by each of said operations in said section and (ii) by the extent of translation between successive said operations.
Other aspects of the invention are as follows:
~17~ 5
-2 ~
A machine for producing a bend in an article, compri-sing a bending station operable to form an incremental bend portion in a section of said article which section will provide said bend, and a movable carriage for translating the article towards and through the bending station, the bending station and the movable carriage being operable alternately such that said section has formed therein a plurality of incremental bend portions to provide said bend and -that the configuration of said bend is determined (i) by the number and the angular deformations of the incremental bend portions and (ii~ by the extents of translation of the carriage between the successive incremental bending operations.
A method of producing a bend in an articlet which com-prises, over a period of time, performing at a bending device a plurality of intermittent bending operations on respective small amounts of a section of said article which section will provide said bend, and, during that period of time, producing relative translation between said section and said bending device, whereby said bending is gradually generated.
A machine for producing a bend in an article compri-sing a bending member for forming an incremental bend portion in a section of said article which section will pro-vide said bend, supporting means for supporting said article, drive means arranged to produce relative translation between said member and said supporting means and thereby relative translation between said member and said article, and relative bending movements between said member and said article on respective small amounts of said section, whereby said bend is graduall~ generated.
By way of added explanation, a machine for bending an elongate article such as a brake pipe may comprise a bend head such as for example a die and former arrangement operable to put a controlled angular extent of bend into a short length of the article, and means operable in sequence ~"'~35 with operation of the die and former arrangement for advan-cing the article through the die and former arrangement by a controlled amount to present a further length for bending.
i5 -2a-The die may be controlled to rock repeatedly over the former so as to put identical incremental bend portions into the article in each bending operation, or alternatively the angu-lar deformation extend of each bend portion may be control-led within an available range by control of the extent ofrelative movement between the die and former in each bend-ing operation. Means may furthermore be provided whereby the article may be rotated about its longitudinal axis by a controlled amount in sequence with its advancement through the die and former arrangement so that the plane of the bend may be varied as required. Work-piece extraction after bend-ing may be achieved by arranging for the die and the former to be pivotable away from one another once a locking means, which is engaged during bending, has been disengaged.
A powered carriage movable by a controllable amount is most conveniently provided for effecting intermittent longitudïnal feed of the article to the bending head, the carriage carrying a clamp, preferably of a pivot lever link-age type, for securing one end of the work-piece to the carriage.
The operating movements of the bend head, which determine the angular extent of each bend portion, .
1171D~5 and the transl~tional and/or axial rotational movements of the article to be bent, which determine respectively the linear and angular distance between successive bend portions, can most readily be controlled by means of a microprocessor or similar data processing apparatus.
In order that the invention might be well understood, a presently preferred embodiment of the invention will hereinafter be described-by way of example only with reference to the accompanying drawings in which: .
Figure 1 shows three typical forms of bent tube;
Figure 2 shows an embodiment of the invention comprising a tube bending machine;
Figure 3 shows a carriage and clamp system for the machine of Figure 2;
Figure 4 i5 a perspective view of *he clamp and carriage of Figure 3;
Figures 5a and 5b are schematic diagrams of the clamp of Figure 3 shown closed and open respectively;
Figures 6a and 6b are perspective views of the bend head of ~igure 2, Figure 6b illustrating the interfitting of the parts in exploded view;
Figure 7 is a sectional view of the inter-fitting parts of the bend head; and Figure 8 shows the bend head opened for work-piece extraction.
The.mar}line in the described embodiment is designed to bend tubes such as hydraulic brake tubes of, typically, 3-13mm diameter metal tubing. These ~ubes are provided to the machine already nutted and flared ancl so the machine is de.~igned to accept and release the nuts, although similar bending techniques .
~17~ i5 and apparatus could be applied to plain tubing, strip ¦ or wire. Figure 1 shows three tubes depicting rvr,ical forms WhiCIl can be produced: the tubes 1 are each provided with end nuts 2.
The general method of bendins consists of a procedure in which the tube is fed through a bending head which engages only a small length of the tube and when operated forms an incremental bend portion of predetermined constant angular extent of for example 5 to 7 , in this small length. The bend head is then disengaged from the tube which is fed through the head by a chosen amount and then a further bend made at another point alons its length. Repetition of the bend-feed-bend procedure can produce different overall curvatures in the tube dependent on the extent of trans-lation, or feed, of the tube between incremental bends_ The minimum radius possible is determined by the degree of bend provided by the bend head and is obtained when the tube is fed by a.length equal to the length over which the bend head acts. For larger radii of curvature the feed length between incremental bends is increased.
~eeding without operation of the bend head enables straight lengths to be left in the tube. Bends in different planes as shown ~ Figure la are obtained by rotation of the tube between bends, whilst a continuously varying plane, such as a helix shown in Figure lb, can be obtained by axially rotating the tube by a few degrees in synchronism with the feed of the tube between succes-sive bends. Variation in the curvature by progressively
A machine for producing a bend in an article, compri-sing a bending station operable to form an incremental bend portion in a section of said article which section will provide said bend, and a movable carriage for translating the article towards and through the bending station, the bending station and the movable carriage being operable alternately such that said section has formed therein a plurality of incremental bend portions to provide said bend and -that the configuration of said bend is determined (i) by the number and the angular deformations of the incremental bend portions and (ii~ by the extents of translation of the carriage between the successive incremental bending operations.
A method of producing a bend in an articlet which com-prises, over a period of time, performing at a bending device a plurality of intermittent bending operations on respective small amounts of a section of said article which section will provide said bend, and, during that period of time, producing relative translation between said section and said bending device, whereby said bending is gradually generated.
A machine for producing a bend in an article compri-sing a bending member for forming an incremental bend portion in a section of said article which section will pro-vide said bend, supporting means for supporting said article, drive means arranged to produce relative translation between said member and said supporting means and thereby relative translation between said member and said article, and relative bending movements between said member and said article on respective small amounts of said section, whereby said bend is graduall~ generated.
By way of added explanation, a machine for bending an elongate article such as a brake pipe may comprise a bend head such as for example a die and former arrangement operable to put a controlled angular extent of bend into a short length of the article, and means operable in sequence ~"'~35 with operation of the die and former arrangement for advan-cing the article through the die and former arrangement by a controlled amount to present a further length for bending.
i5 -2a-The die may be controlled to rock repeatedly over the former so as to put identical incremental bend portions into the article in each bending operation, or alternatively the angu-lar deformation extend of each bend portion may be control-led within an available range by control of the extent ofrelative movement between the die and former in each bend-ing operation. Means may furthermore be provided whereby the article may be rotated about its longitudinal axis by a controlled amount in sequence with its advancement through the die and former arrangement so that the plane of the bend may be varied as required. Work-piece extraction after bend-ing may be achieved by arranging for the die and the former to be pivotable away from one another once a locking means, which is engaged during bending, has been disengaged.
A powered carriage movable by a controllable amount is most conveniently provided for effecting intermittent longitudïnal feed of the article to the bending head, the carriage carrying a clamp, preferably of a pivot lever link-age type, for securing one end of the work-piece to the carriage.
The operating movements of the bend head, which determine the angular extent of each bend portion, .
1171D~5 and the transl~tional and/or axial rotational movements of the article to be bent, which determine respectively the linear and angular distance between successive bend portions, can most readily be controlled by means of a microprocessor or similar data processing apparatus.
In order that the invention might be well understood, a presently preferred embodiment of the invention will hereinafter be described-by way of example only with reference to the accompanying drawings in which: .
Figure 1 shows three typical forms of bent tube;
Figure 2 shows an embodiment of the invention comprising a tube bending machine;
Figure 3 shows a carriage and clamp system for the machine of Figure 2;
Figure 4 i5 a perspective view of *he clamp and carriage of Figure 3;
Figures 5a and 5b are schematic diagrams of the clamp of Figure 3 shown closed and open respectively;
Figures 6a and 6b are perspective views of the bend head of ~igure 2, Figure 6b illustrating the interfitting of the parts in exploded view;
Figure 7 is a sectional view of the inter-fitting parts of the bend head; and Figure 8 shows the bend head opened for work-piece extraction.
The.mar}line in the described embodiment is designed to bend tubes such as hydraulic brake tubes of, typically, 3-13mm diameter metal tubing. These ~ubes are provided to the machine already nutted and flared ancl so the machine is de.~igned to accept and release the nuts, although similar bending techniques .
~17~ i5 and apparatus could be applied to plain tubing, strip ¦ or wire. Figure 1 shows three tubes depicting rvr,ical forms WhiCIl can be produced: the tubes 1 are each provided with end nuts 2.
The general method of bendins consists of a procedure in which the tube is fed through a bending head which engages only a small length of the tube and when operated forms an incremental bend portion of predetermined constant angular extent of for example 5 to 7 , in this small length. The bend head is then disengaged from the tube which is fed through the head by a chosen amount and then a further bend made at another point alons its length. Repetition of the bend-feed-bend procedure can produce different overall curvatures in the tube dependent on the extent of trans-lation, or feed, of the tube between incremental bends_ The minimum radius possible is determined by the degree of bend provided by the bend head and is obtained when the tube is fed by a.length equal to the length over which the bend head acts. For larger radii of curvature the feed length between incremental bends is increased.
~eeding without operation of the bend head enables straight lengths to be left in the tube. Bends in different planes as shown ~ Figure la are obtained by rotation of the tube between bends, whilst a continuously varying plane, such as a helix shown in Figure lb, can be obtained by axially rotating the tube by a few degrees in synchronism with the feed of the tube between succes-sive bends. Variation in the curvature by progressively
3~ changing the feed lengths between incremental bends gives rise to a 'snail' form as shown in Figure lc. ~ince each incremental bend may be formed in the same or a different plane from the adjacent bends, the only con-straints on the shape and curvature of bent tubing formed 1~7`~ 5 according to the invcntion are those of minimum bend radius as dictated by the bend head construction, and spatial limitations imposed by the machine itself obstructing the bent tube.
Figure 2 shows the bending machine which consists of a carriage and clamp, indicated generally as 3 and a bend head 4. The bending machine is shown free standing but it may be suspended from a wall or ceiling or be mounted on an arm or gimbal. An important feature of the machine is its compactness, which enables the tube to be bent back on itself through large angles and minimises the aforementioned limitation of the machine bulk restricting the ranse of curvature.
Figures 3 and 4 show the carriage which com-prises a cylindrical body 5 containing a double acting hydraulic cylinder 6 which is attached to an ac*ivating member 7 of a pull type lazy-tongs clamp mechanism shown generally as 8. The cylindrical body 5 is provided with lateral wheels 9 which enable it to run in a channel 38 which extends to the bend head 4. The nut at the end of the tube workpiece is accommodated by the clamp 8 and the tube extends forwardly through the bend head 4. A
toothed belt 10, which may be seen in Figure 2, extends from pulleys 11 at the base of the machine and around pulleys 12 on the bend head. This belt is driven by a motor 13 and engages with slots on e~h side of the carriage to transport the carriage upwards (as viewed) and feed tube 1 into the bend head 4. Bent workpieces are removed and new workpieces inserted when the carriage abuts the bend head. Once a new workpiece has been received, belt 10 reverses the carriage 3 away from the bend head back to its starting p~sition to commence transport of the new workpiece into the bend head.
A frame 22 is journalled as shown in Fisure 3 within the cylindrical body 5 and is connected through ~7~ 5 01 gearing 40, 42 ~ith an electric motor 44 mounted on the cylindrical body 5. The motor 44, preferably a stepping motor, serves for rotating frame 22 and the clamp 8 and the engaged tube by controlled amounts dependent upon signals applied to the motor 44 so that the tube can be bent in various planes. Frame 22 is not translatable with respect to body 5, but actuator 7 is longitudinally translatable by a small amount within the frame under control of hydraulic cylinder 6.
Figure Sa and 5b show schematically the clamp system 8, which consits of actuator 7, links 14 and 15 and jaws 16 and 17. Links 14 and 15 are pivotally connected to the actuator by pivot pin 18, link 14 is pivoted by pin 19 to upper jaw 17, link 15 is pivoted by pin 20 to lower jaw 16, and jaws 16 and 17 are pivotally connected by pin 21. Lower jaw 16 is bifur-cated to accommodate upper jaw 17 and link 15 between the bifurcations (see Figure 4), and links 14 and 15 are slotted to fit around actuator 7 at their mutual pivotal connection. Upper jaw 17 is bifurcated in order to accommodate link 14 and the end portion of frame 22 between the bifurcations.
Jaws 16 and 17 are separated by actuator 7 moving to the left under the influence of hydraulic cylinder 6, from the position~as viewed in Figure 5a to the position shown in Figure 5b. This causes links 14 and 15 and hence jaws 16 and 17 to move apart.
Closure of the jaws is accomplished by retraction of the actuator 7 back to the position shown in Figure 5a which moves links 14 and 15, and hence jaws 16 and 17 back together. The bushing for pivot pin 21 is elongated in the direction of movement of the actuator 7, and this elongation enables the movement of the actuator to translate the lever linkage of the clamp 8 a small 3L1'7~ 5 distance in the same direction as the actuator movement for a purposc explained hereinafter.
Frame 22 is recessed to accommodate a mandrel insert 23 (Figure 3) on which the end of the tube 1 and nut 2 can be located. Mandrel 23 is interchan5e-able so that different types of nut may be accommodated.
In order to enable rapid interchange of mandrels~ the mandrel may be magnetically located and/or 'snap' fitting.
When a new workpiece is inserted into the open jaws, the ends of the nut 2 and tube are engaged by the mandrel.
The actuator 7 then causes the jaws to close and lastly the lever linkage is translated due to the abovementioned bushing elongation which draws the nut 2 back again~i the mandrel. On removal of the workpiece from the clamp 8, the translation of the linkage in the opposite direction first pulls the nut away from the base of the mandrel, --and then the jaws open.
A resilient bias, for instance applied between pivot pins 19 and 20 biasing jaws 16 and 17 together, may be provided to ensure that the bushins travel is ; taken at.the correct instant with respect to the opening and closure of the jaws to facilitate reception or ejection of the nut 2 on the end of the workpiece.
The bend head 4 is shown in perspective in Figure 6a; Figure 6b is an exploded perspective view of the die, former and frame of the bend head, and Figure 7 is a sectional view showing how these parts interfit. The bend head comprises a die consisting of a bending portion 24 and an actuating portion 25, 30 a former 26 and a frame 27. A double acting ram 28 is linked to the actuating portion 25 of the die for rocking this so as to cause the connected bending portion 2~ of the die to rock over the former 26 thereby to bend a tube 1 which is engaged in shaped recesses in ~ 7L~S
the former 26 and bending portion 24 of the die. Ram 28 may have a variable stroke ampli*ude ~hich is controlled in conjullctioll~Yith the required curvature of the tube, e.g. a larger amplitude may be used when a small radius of curvature is desired and vice versa.
Bendins portion 24 is connected to actuating portion 25 of the die by a cylindrical extension 24a which passes through a bore 25a in the actuating portion 25. Former 26 has a hollow cylindrical extension 26c 10 which extends through bores 27c in the frame 27 and bore 25c in the actuating portion of the die to secure the die and former to the frame 27. The bending portion 24 of the die is rotatable axially about exten-sion 24a journalled in bore 25a of the actuating portion 25, and former 26 is rotatable axially about extension 26c journalled in bores 27c and 25c. When the head is being used for bending, two locking pins 29 and 30 are inserted, pin 30 passing along the centre of hollow cylindrical extension 26c and into recess 24c in the bending portion 24 of the die, and pin 29 passing through bores 27b in frame 27, through bore 25b in the actuating portion of the die and into recess 26b in former 26.
Insertion and withdrawal of these pins is controlled by a solenoid 31. When ram 28 is operated, the die 24 is roc~ed over former 26, with pin 30 acting as a pivot.
In order to permit this rocking motion the bore 25b in the actuated portion 25 of the die is arcuate in cross-section.
When the bending of a workpiece is finished the 3 nut 2 held in the clamp 8 of the carriage is relcased, and in order that the workpiece can be rcmoved from the bend head the solenoid 31 withdraws the pins 29 and 30 from their pOSitiOlIS locking the bending portion 2~ of tl-e die and the former 26, and these parts are ~7~ 5 pushed open to the positions shown in Figure 8 by the nut 2 as it is pulled through the bend head. As the bending portion 24 of the die rotates upwards about its cylindrical extension 24a, it rotates lever 32 upwards taking one arm of a pivotally connected crank 33 with it. The other arm of crank 33 is pivotally con-nected to a lever 34 which is in turn connected to the cylindrical extension 26c of the former 26. This lever linl;age ensure that both the bending portion 24 of the die and the former 26 open if only one is pushed.
A small amount of lost motion is provided in the linkage to accommodate the rocking movement of the die during a bending operation.
The open position of the bend head shown in Figure 8 is maintained by the over centre action of a spring 35 so that a new workpiece can be inserted into the jaws of the clamp 8 situated immediately behind the bend head. A loading mechanism for the new work-piece can be arranged to push the bend head back to 20 the closed position, e.g. by a member pushing the bending portion 24 of the die so that the lever linkage 32, 33, 34 causes the former to follow. The locking pins 29 and 30 can then be inserted and the carriage 3 retracted to its starting position to commence bending 25 the new workpiece.
A microprocesAsor or othor computer control unit shown at 50 in Figure 2 may advantageously be used to synchronise and control the feed and ro*ation of the tube and operation of the bend head. The microprocessor 30 can be programmed to ensure that~ after the last bend, the jaws of the clamp o are rotated ~so that they are correctly aligned for opening without becoming ob-structed by the bend hcad.
In nn alternative arrangement for the machine, :1~7~ ;5 -- 10 _ the bend head and carriage are mounted on the end le~er of an articulated lever arm. The worlcpiece is loadcd so that the nut on its first end is resting on a support, the nut at the second end being held in the clamp. As the bent tube emerges from the bend 'head the articulated arm moves so that the emergent tube is balanced on the support. Computation of the instantaneous centre of gravity of the emergent tube and the relative movement of the arm may be performed by the microprocessor.
.. . .
Ii
Figure 2 shows the bending machine which consists of a carriage and clamp, indicated generally as 3 and a bend head 4. The bending machine is shown free standing but it may be suspended from a wall or ceiling or be mounted on an arm or gimbal. An important feature of the machine is its compactness, which enables the tube to be bent back on itself through large angles and minimises the aforementioned limitation of the machine bulk restricting the ranse of curvature.
Figures 3 and 4 show the carriage which com-prises a cylindrical body 5 containing a double acting hydraulic cylinder 6 which is attached to an ac*ivating member 7 of a pull type lazy-tongs clamp mechanism shown generally as 8. The cylindrical body 5 is provided with lateral wheels 9 which enable it to run in a channel 38 which extends to the bend head 4. The nut at the end of the tube workpiece is accommodated by the clamp 8 and the tube extends forwardly through the bend head 4. A
toothed belt 10, which may be seen in Figure 2, extends from pulleys 11 at the base of the machine and around pulleys 12 on the bend head. This belt is driven by a motor 13 and engages with slots on e~h side of the carriage to transport the carriage upwards (as viewed) and feed tube 1 into the bend head 4. Bent workpieces are removed and new workpieces inserted when the carriage abuts the bend head. Once a new workpiece has been received, belt 10 reverses the carriage 3 away from the bend head back to its starting p~sition to commence transport of the new workpiece into the bend head.
A frame 22 is journalled as shown in Fisure 3 within the cylindrical body 5 and is connected through ~7~ 5 01 gearing 40, 42 ~ith an electric motor 44 mounted on the cylindrical body 5. The motor 44, preferably a stepping motor, serves for rotating frame 22 and the clamp 8 and the engaged tube by controlled amounts dependent upon signals applied to the motor 44 so that the tube can be bent in various planes. Frame 22 is not translatable with respect to body 5, but actuator 7 is longitudinally translatable by a small amount within the frame under control of hydraulic cylinder 6.
Figure Sa and 5b show schematically the clamp system 8, which consits of actuator 7, links 14 and 15 and jaws 16 and 17. Links 14 and 15 are pivotally connected to the actuator by pivot pin 18, link 14 is pivoted by pin 19 to upper jaw 17, link 15 is pivoted by pin 20 to lower jaw 16, and jaws 16 and 17 are pivotally connected by pin 21. Lower jaw 16 is bifur-cated to accommodate upper jaw 17 and link 15 between the bifurcations (see Figure 4), and links 14 and 15 are slotted to fit around actuator 7 at their mutual pivotal connection. Upper jaw 17 is bifurcated in order to accommodate link 14 and the end portion of frame 22 between the bifurcations.
Jaws 16 and 17 are separated by actuator 7 moving to the left under the influence of hydraulic cylinder 6, from the position~as viewed in Figure 5a to the position shown in Figure 5b. This causes links 14 and 15 and hence jaws 16 and 17 to move apart.
Closure of the jaws is accomplished by retraction of the actuator 7 back to the position shown in Figure 5a which moves links 14 and 15, and hence jaws 16 and 17 back together. The bushing for pivot pin 21 is elongated in the direction of movement of the actuator 7, and this elongation enables the movement of the actuator to translate the lever linkage of the clamp 8 a small 3L1'7~ 5 distance in the same direction as the actuator movement for a purposc explained hereinafter.
Frame 22 is recessed to accommodate a mandrel insert 23 (Figure 3) on which the end of the tube 1 and nut 2 can be located. Mandrel 23 is interchan5e-able so that different types of nut may be accommodated.
In order to enable rapid interchange of mandrels~ the mandrel may be magnetically located and/or 'snap' fitting.
When a new workpiece is inserted into the open jaws, the ends of the nut 2 and tube are engaged by the mandrel.
The actuator 7 then causes the jaws to close and lastly the lever linkage is translated due to the abovementioned bushing elongation which draws the nut 2 back again~i the mandrel. On removal of the workpiece from the clamp 8, the translation of the linkage in the opposite direction first pulls the nut away from the base of the mandrel, --and then the jaws open.
A resilient bias, for instance applied between pivot pins 19 and 20 biasing jaws 16 and 17 together, may be provided to ensure that the bushins travel is ; taken at.the correct instant with respect to the opening and closure of the jaws to facilitate reception or ejection of the nut 2 on the end of the workpiece.
The bend head 4 is shown in perspective in Figure 6a; Figure 6b is an exploded perspective view of the die, former and frame of the bend head, and Figure 7 is a sectional view showing how these parts interfit. The bend head comprises a die consisting of a bending portion 24 and an actuating portion 25, 30 a former 26 and a frame 27. A double acting ram 28 is linked to the actuating portion 25 of the die for rocking this so as to cause the connected bending portion 2~ of the die to rock over the former 26 thereby to bend a tube 1 which is engaged in shaped recesses in ~ 7L~S
the former 26 and bending portion 24 of the die. Ram 28 may have a variable stroke ampli*ude ~hich is controlled in conjullctioll~Yith the required curvature of the tube, e.g. a larger amplitude may be used when a small radius of curvature is desired and vice versa.
Bendins portion 24 is connected to actuating portion 25 of the die by a cylindrical extension 24a which passes through a bore 25a in the actuating portion 25. Former 26 has a hollow cylindrical extension 26c 10 which extends through bores 27c in the frame 27 and bore 25c in the actuating portion of the die to secure the die and former to the frame 27. The bending portion 24 of the die is rotatable axially about exten-sion 24a journalled in bore 25a of the actuating portion 25, and former 26 is rotatable axially about extension 26c journalled in bores 27c and 25c. When the head is being used for bending, two locking pins 29 and 30 are inserted, pin 30 passing along the centre of hollow cylindrical extension 26c and into recess 24c in the bending portion 24 of the die, and pin 29 passing through bores 27b in frame 27, through bore 25b in the actuating portion of the die and into recess 26b in former 26.
Insertion and withdrawal of these pins is controlled by a solenoid 31. When ram 28 is operated, the die 24 is roc~ed over former 26, with pin 30 acting as a pivot.
In order to permit this rocking motion the bore 25b in the actuated portion 25 of the die is arcuate in cross-section.
When the bending of a workpiece is finished the 3 nut 2 held in the clamp 8 of the carriage is relcased, and in order that the workpiece can be rcmoved from the bend head the solenoid 31 withdraws the pins 29 and 30 from their pOSitiOlIS locking the bending portion 2~ of tl-e die and the former 26, and these parts are ~7~ 5 pushed open to the positions shown in Figure 8 by the nut 2 as it is pulled through the bend head. As the bending portion 24 of the die rotates upwards about its cylindrical extension 24a, it rotates lever 32 upwards taking one arm of a pivotally connected crank 33 with it. The other arm of crank 33 is pivotally con-nected to a lever 34 which is in turn connected to the cylindrical extension 26c of the former 26. This lever linl;age ensure that both the bending portion 24 of the die and the former 26 open if only one is pushed.
A small amount of lost motion is provided in the linkage to accommodate the rocking movement of the die during a bending operation.
The open position of the bend head shown in Figure 8 is maintained by the over centre action of a spring 35 so that a new workpiece can be inserted into the jaws of the clamp 8 situated immediately behind the bend head. A loading mechanism for the new work-piece can be arranged to push the bend head back to 20 the closed position, e.g. by a member pushing the bending portion 24 of the die so that the lever linkage 32, 33, 34 causes the former to follow. The locking pins 29 and 30 can then be inserted and the carriage 3 retracted to its starting position to commence bending 25 the new workpiece.
A microprocesAsor or othor computer control unit shown at 50 in Figure 2 may advantageously be used to synchronise and control the feed and ro*ation of the tube and operation of the bend head. The microprocessor 30 can be programmed to ensure that~ after the last bend, the jaws of the clamp o are rotated ~so that they are correctly aligned for opening without becoming ob-structed by the bend hcad.
In nn alternative arrangement for the machine, :1~7~ ;5 -- 10 _ the bend head and carriage are mounted on the end le~er of an articulated lever arm. The worlcpiece is loadcd so that the nut on its first end is resting on a support, the nut at the second end being held in the clamp. As the bent tube emerges from the bend 'head the articulated arm moves so that the emergent tube is balanced on the support. Computation of the instantaneous centre of gravity of the emergent tube and the relative movement of the arm may be performed by the microprocessor.
.. . .
Ii
Claims (16)
1. A method of producing a bend in an article which comprises translating intermittently and by controlled amounts relative to a bending station a section of said article which section will provide said bend, and mean-while performing at said station a plurality of inter-mittent bending operations alternating with the trans-lations of the article relative to said station, whereby said bend is gradually generated and the configuration of said bend is determined (i) by the number of said operations and the angular deformation produced by each of said operations in said section and (ii) by the extents of translation between successive said opera-tions.
2. A method as claimed in claim 1 wherein identical incremental bend portions are formed in the respective intermittent bending operations.
3. A method as claimed in claim 1 wherein different incremental bend portions are formed in the respective intermittent bending operations, these portions having different angular deformation extents controllable by an operator.
4. A method as claimed in claim 1, and further comp-rising rotating the article about a longitudinal axis thereof through a controllable angular extent to deter-mine different bend planes.
5. A machine for producing a bend in an article, comp-rising a bending station operable to form an incremental bend portion in a section of said article which section will provide said bend, and a movable carriage for translating the article towards and through the bending station, the bending station and the movable carriage being operable alternately such that said section has formed therein a plurality of incremental bend portions to provide said bend and that the configuration of said bend is determined (i) by the number and the angular deformations of the incremental bend portions and (ii) by the extents of translation of the carriage between the successive incremental bending operations.
6. A machine as claimed in claim 5 wherein the bending station is adapted to form an incremental bend portion of predetermined constant angular deformation extent in each bending operation.
7. A machine as claimed in claim 5 wherein the bending station comprises a bending head including relatively movable die and former components operated by means of a powered actuator.
8. A machine as claimed in claim 7 wherein the die and former components of the bending head are movable out of operative relationship with one another for disengaging a finished article, and solenoid operated locking pins are provided for securing the die and form-er components in operative relationship during bending operations, the solenoid being controllable by an operator for determining the operational condition of the bending head.
9. A machine as claimed in claim 5 wherein the carr-iage is movable towards and away from the bending station along a predetermined fixed path under control of a motor and carries a clamping means adapted for clamping and holding one end of an elongate article to be bent.
10. A machine as claimed in claim g wherein the clamp-ing means is of the lazy-tongs type and incorporates an actuator operable for opening and closing the clamping means.
11. A machine as claimed in claim 9 wherein the carri-age further comprises means for controllably rotating said clamping means for rotating an elongate article held therein about a longitudinal axis of said article so as to determine the bending plane of the incremental bend portions.
12. A machine as claimed in claim 5, 6, or 9, adapted and arranged to be coupled with a data processing apparatus and to receive from the data processing apparatus control signals such as to determine the operation of the bending machine so as to obtain the required article configuration.
13. A method of producing a bend in an article, which comprises, over a period of time, performing at a bending device a plurality of intermittent bending operations on respective small amounts of a section of said article which section will provide said bend, and, during that period of time, producing relative translation between said section and said bending device, whereby said bend is gradually generated.
14. A method according to claim 1, wherein said relative translation comprises a plurality of relative translations alternating with the intermittent bending operations.
15. A method according to claim 14, wherein, prior to the production of said bend, gripping means advances to an advanced position, there grips a nearer end zone of said article, retracts with said article to a retracted position, and begins to advance towards said advanced position, and, after the production of said bend, said gripping means releases said article.
16. A machine for producing a bend in an article comprising a bending member for forming an incremental bend portion in a section of said article which section will provide said bend, supporting means for supporting said article, drive means arranged to produce relative translation between said member and said supporting means and thereby relative translation between said member and said article, and relative bending movements between said member and said article on respective small amounts of said section, whereby said bend is gradually generated.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7940638 | 1979-11-23 | ||
| GB7940638 | 1979-11-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1170965A true CA1170965A (en) | 1984-07-17 |
Family
ID=10509393
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000365216A Expired CA1170965A (en) | 1979-11-23 | 1980-11-21 | Incremental bending method and apparatus |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0029694A1 (en) |
| JP (1) | JPS56131015A (en) |
| AU (1) | AU6450180A (en) |
| CA (1) | CA1170965A (en) |
| ZA (1) | ZA807292B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH089063B2 (en) * | 1985-10-21 | 1996-01-31 | 臼井国際産業株式会社 | Bending unit device in automatic pipe bender |
| NZ564570A (en) * | 2007-12-18 | 2010-02-26 | Scott Technology Ltd | Metal folding apparatus |
| DE102014108079A1 (en) * | 2014-06-06 | 2015-12-17 | Kottmann Und Berger Gmbh | bending machine |
| CN107811347B (en) | 2016-09-13 | 2022-06-10 | 梅姆布拉恩安全解决方案公司 | Method and system for vending collapsible bicycle helmets |
| US11864617B2 (en) | 2016-09-13 | 2024-01-09 | memBrain Safety Solutions, LLC | Machine vendible expandable helmet and manufacture of same |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3493016A (en) * | 1967-06-16 | 1970-02-03 | Lear Siegler Inc | Wire bending machine |
| DE1982791U (en) * | 1967-09-13 | 1968-04-04 | Rigobert Dipl Ing Schwarze | NUMERICALLY CONTROLLED, AUTOMATIC TUBE BENDING MACHINE WITH PRESSURE FEED. |
| US3662575A (en) * | 1970-02-26 | 1972-05-16 | Oldberg Mfg Co | Method and apparatus for bending tubing |
| US3958440A (en) * | 1974-12-09 | 1976-05-25 | Frank Sassak | Universal tube bending machine |
| US3986381A (en) * | 1975-05-05 | 1976-10-19 | Vladimir Nikolaevich Shubin | Bending head for a tube bending machine |
| US4052878A (en) * | 1976-08-02 | 1977-10-11 | Connelly Dennis E | Tube bending apparatus |
| US4131003A (en) * | 1977-06-07 | 1978-12-26 | The Boeing Company | Semiautomatic control system for tube bending machine |
| DE2746721C3 (en) * | 1977-10-18 | 1981-03-19 | Schwarze, Rigobert, Dipl.-Ing., 5000 Köln | Tube bending machine |
-
1980
- 1980-11-18 EP EP80304123A patent/EP0029694A1/en not_active Withdrawn
- 1980-11-19 AU AU64501/80A patent/AU6450180A/en not_active Abandoned
- 1980-11-21 CA CA000365216A patent/CA1170965A/en not_active Expired
- 1980-11-21 ZA ZA00807292A patent/ZA807292B/en unknown
- 1980-11-25 JP JP16576780A patent/JPS56131015A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| EP0029694A1 (en) | 1981-06-03 |
| ZA807292B (en) | 1981-11-25 |
| JPS56131015A (en) | 1981-10-14 |
| AU6450180A (en) | 1981-05-28 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |