GB1570064A

GB1570064A - Bending machine

Info

Publication number: GB1570064A
Application number: GB17128/78A
Authority: GB
Original assignee: Buxton Ltd R & A
Current assignee: Buxton Ltd R & A
Priority date: 1978-04-29
Filing date: 1978-04-29
Publication date: 1980-06-25

Description

(54) BENDING MACHINE (71) We, R. & A. BUXTON, LIMITED a British Company of Salop Street, Bradley, Bilston, West Midlands do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be par tictilarly described in and by the following statement: This invention relates to a machine of the kind, hereinafter called the kind specified, comprising a pair of support rolls mounted side by side to define a gap between them and a bending roll mounted for movement towards and away from said gap, each roll being supported for rotation about a respective axis by a respective pair of bearings which are spaced apart along the roll and the roll axes being under at least scone conditions of use, parallel to each other.

Machines of the kind specified are used primarily for bending metal plates into cylindrical or other curved forms. A plate which is to be bent is inserted from one side of the machine with one face of the plate presented towards the support rolls and an opposite face of the plate presented towards the bending roll. Leading and trailing edges of the plate may be bent by use of an anvil. Subsequently the plate is rolled between the bending roll on the one hand and the support rolls on the other, the bending roll being moved towards or into the gap between the support rolls to form the plate to the required curvature. Usually, a motor is provided for rotating the support rolls and the bending roll is rotated by movement of the plate. The plate is curved around the bending roll and, in a case where the plate is formed into a cylinder, the cylinder must be removed from the bending roll at one end thereof.

Accordingly, it is known to mount removably in a carrier a bearing which supports the bending roll at one end thereof, called herein the discharge end. The carrier and bearing can be separated so that a formed cylinder can be moved off the bending roll and the bearing at the discharge end thereof. When this bearing is separated from its carrier, the bending roll is no longer supported at its discharge end and an abutment is arranged to prevent upward movement of an opposite end of the bending roll and thereby prevent the discharge end of the bearing roll falling when the carrier is separated from the bearing. In practice the abutment is normally used to depress said apposite end of the bending roll slightly and thereby relieve the carrier of the load which it usually bears so that separation of the bearing from the carrier is facilitated.

In certain known machines of the kind specified the abutment is adjustable so that it can be brought into engagement with the bending roll at all positions of the bending roll relative to the support rolls. This has a serious disadvantage. If, whilst the bending roll is in some position between the limits of its travel towards and away from the gap between the support rolls, the abutment is moved into engagement with the bending roll to relieve the carrier at the discharge end of its load and the abutment is not withdrawn as far as possible from the bending roll when the carrier is once more engaged with its bearing, it is possible by raising the bending roll away from the support rolls to subject the bending roll to a severe bending load between the two associated bearings and the abutment. This can result in serious damage being caused to the machine.

Other known machines have a fixed abutment which becomes operative to relieve the carrier if its load only when the bending roll is in its uppermost position. This does not avoid the risk of serious damage being caused by subjecting the bending roll to a severe bending load between its two bearings and the abutment, since the bearings are usually movable independently of each other at least to some degree, to enable the bending roll to be tilted relative to the support rolls. Such tilting is useful in certain circumstances. If the bending roll is tilted so that its discharge end is lower than its opposite end and the bending roll is then raised, said opposite end will engage the abutment before the bearings reach their highest positions. Continued movement of the bearings is likely to damage the machine.

Aocording to the invention, there is provided a marine of the kind specified comprising an abutment for exerting a downwards force on an end portion of the bending roll remote from the discharge end thereof wherein the abutment is movable between an inoperative position and a sole operative position with respect to the bending roll, the abutment exerting said force on the roll only when the abutmen is in its operative position and said end portion is in the limit position which it occupies when the bending roll is at the limit of its travel in a direction away from the gap between the support rolls and the bending roll axis is parallel to the support roll axes.

In the known machines with adjustable abutments hereinbefore described, the abutrents have an infinite number of operative positions corresponding to the various positions in which the bending roll can be set; whereas a machine in accordance with the invention has a sole operative position which corresponds to the position of the bending roll at the limit of its travel in a direction away from the gap between the support rolls. When the bearing which supports the discharge end of the bearing roll is to be separated from its carrier, the bending roll is moved to this position. During this movement of the bending roll, the abutment is maintained in its inoperative position so that even if the bending roll is moved whilst it is tilted relative to the support rolls, the abutment will not exert a significant force on the bending roll. Only when the movement of the bending roll has been completed is the abutment moved to its operative position.

The invention will now be described, by way of example, with reference to the accompany- ing drawings wherein: FIGURE 1 shows a perspective view of a machine in accordance with the invention, a bending roll of the machine having been pivoted to a discharge position, FIGURE 2 shows a partial end elevation of the machine on the arrow II of Figure 1, certain parts being broken away, FIGURE 3 shows a part of an opposite end elevation of the machine, an end cover being omitted.

FIGURE 4 shows a side elevation of the parts shown in Figure 3, and FIGURE 5 shows a plan view ob the parts shown in Figure 3.

The machine comprises a pair of support rolls 1 and 2 which are mounted side by side to define a gap between them, the width of the gap being sornewhat less than the diameter of the support rolls. The roll 1 is supported for rotation about a horizontal axis 3 by a par of bearings 4 and 5 situated near to opposite ends of the roll and carried by a base 6 of the machine. The roll 2 is similarly supported for rotation about an axis 7 which is parallel to the axis 3, the bearings associated with the roll 2 being fixed with respect to the bearings 4 and 5.

The machine further comprises a bending roll 8 which, in its working position (not fully illustrated), lies above the gap between the support rolls 1 and 2 with its axis 9 lying in a vertical plane between the axes 3 and 7.

When in its working position, the bending roll is supported by bearings 10 and 11 which lie adjacent to the bearings 4 and 5 respectively.

The bearing L1 is releasably mounted in a carrier 12 which is illustrated in Figure 2. The bearing 10 is mounted in a further carrier 13 which may be similar to the carrier 12. The carriers 12 and 13 are mounted on the base 6 for adjustment relative thereto about a common horizontal axis 14 which is parallel to the axes 3 and 7 but is offset laterally therefrom. When the bending roll 8 is in its working position, movement of the carriers 12 and 13 about the axis 14 moves the bending roll towards and away from the gap between the support rolls 1 and 2. The range of possible movement extends from an uppermost position to a lowermost position in which the bending roll is partly disposed in the gap between the support rolls.

The bearings 10 and 11 are so constructed that the outer race of each bearing can be inclined to the axis 9. Thus, if the bearing 11 is released from the carrier 12, the roll 8 can pivot about a vertical pivot axis 15 passing through or near to the bearing 10 to the discharge position illustrated in Figure 1. When the roll 8 is in the discharge position, the bearing 11 is separated from the carrier 12 and a cylindrical workpiece can be removed from the roll over the end thereof adjacent to the bearing 1X1, which is called the discharge end of the roll.

The carriers 12 and 13 can be moved independently about the axis 14 by adjusting means composing respective hydraulic motors (not shown). The positions of the carriers are indicated at a control panel 16. By independent movement of the carriers 12 and 13, the roll 8 can be tilted relative to the support rolls 1 and 2 sothat either the discharge end or an opposite end of the bending roll is uppermost.

Such tilting moves the axis 9 out of coincidence with the axes of the outer races of the bearings 10 and L1.

On an end portion of the bending roll 8 remote from the discharge end thereof, there is mounted a roller 17 which is rotatable about the axis 9 relative to the roll. There is provided for cboperation with the roller 17 an abutment 18 which is used to exert a downwards force on the bending roll and so prevent the discharge end of the bearing roll falling when the bearing 11 is separated from the carrier 12. As shown in Figure 3, the abutment is in the form of an elongate plate pivoted adjacent to one of its ends for move ment about a horizontal axis 19 which is parallel to the axis 3. There is pivotally connected to an opposite end portion of the plate 18 a first arm 20 of a toggle linkage which also comprises a shorter arm 21. By means of the toggle linkage, the plate 18 can be pivoted about the axis 19 from the operative position shown in Figure 3 in full lines to the inoperative position shown in Figure 3 by a broken line.

When the plate 18 is in its inoperative position, it remains dear of the roller 17 even if the carrier 13 is pivoted upwardly to the limit of its travel whilst the bending roll 8 is so tilted that its discharge end is lowermost. If, when the carriers 12 and 13 are both in their uppermost positions, the roller 17 then being in the limit position shown in Figures 3 and 4, the plate 18 is pivoted into its operative position, it exerts on the bending roll 8 via the roller 17 a downwards force which is sufficiently great to relieve the carrier 12 of the load nonnally imposed thereon by the bearing 11.

As shown, provision is made for making small adjustments of the operative position of the plate 18 during manufacture of the machine so that the required downwards force can be established. The operative position of the plate is clearly defined by the toggle linkage and the toggle linkage does not allow the plate to move below its operative position.

The machine further comprises pivot control means which prevents pivoting of the bending roll 8 about the pivot axis 15 from the working position to the discharge position unless the plate 18 is in its operative position and the bending roll is in its uppermost position so that the required downwards force is exerted on the bending roll by the abutment plate. The pivot control means comprises a stop member 22 having a curved edge 23 which normally lies very close to or just touches the roller 17.

The edge 23 is an arc of a circle centered on the axis 14 so that when the bending roll 8 is in its working position and is moved towards and away from the gap between the rolls 1 and 2, the roller 17 moves along the edge 23. The stop member 22 lies at the side of the bending roll 8 towards which the roller 17 moves when the bending roll is pivoted to its discharge position. Accordingly, the stop member nor mally obstructs pivoting of the bending roll to its discharge position and maintains the bend ing roll in its working position.

Except when the bending roll 8 is in its uppermost position, the stop member 22 is maintained close to or in engagement with the roller 17 by a guide element 24. The guide element is rigidly secured to the stop member 22 and has a marginal portion 25 which is received in a peripheral groove 26 defined by the roll 8 adjacent to the roller 17. Whilst the marginal portion 25 is within the groove 26, the edge 23 of the stop member is constrained to lie adjacent to the periphery of the roller 17. A boundary of the groove 26 remote from the roller 17 is formed by a disc 27. A sector of a circle having a diameter slightly greater than that of the disc 27 is cut from the marginal portion 25 of the guide element, the arrangement being such that when the bending roller 8 is in its uppermost position, no part of the guide element lies within the groove 26.

The stop member 22 can then swing about a vertical axis 28 to move the edge 23 of the stop member away from the roller 17 past the disc 27 to the position indicated by a broken line in Figure 5. When the stop member has been moved to this position and the bearing 11 has been released from the carrier 12, the bending roll 8 can be pivoted to its discharge position.

Whilst the bending roll remains in its discharge position, the disc 27 obstructs return of the stop member 22 to its normal position indicated in full lines in Figure 5.

For operating the toggle linkage 20 and 21 and for operating the pivot control means, there is provided a common operating member in the form of a handle 29. The handle is mounted on a bracket 30 carried by an arm 31 which can pivot about a horizontal axis 32.

The shorter arm 21 of the toggle linkage also moves about the axis 32 and is rigidly connected with the arm 31 by a horizontal shaft.

The handle 29 is further guided for movement about the axis 32 by a ball bearing 33, an outer race of which rolls along an arcuate portion 34 of a track which is fixed with respect to the base 6. At one end ob the arcuate portion 34, there is a part 35 of the track which extends generally towards the axis 32.

When the outer race of the bearing 33 is disposed in the part 35 of the track, the handle 29 can be rocked relative to the bracket 30 about a pivot 36 to move the stop member 22 away from the periphery of the roller 17. The handle 29 is connected with the stop member 22 by links 39a to 39g. If the marginal portion 25 of the guide element is within the groove 26, these links prevent pivoting of the handle about the pivot 36 relative to the bracket 30.

Also, when the stop member 22 is held in the position indicated by the broken line in Figure 5, the handle 29 is retained in the radial part 35 of the track and cannot be moved along the arcuate portion 34 of the track in a direction to move the plate 18 to its inoperative position. Thus, there is no risk of the discharge end of the bending roll being permitted to fall whilst the roll is in its discharge position.

It will be noted that as the discharge roll 8 is pivoted about the axis 15, the roller 17 rolls across the undersurface of the plate 18. To facilitate operation of the toggle mechanism by the handle 29, the plate 18 is counterbalanced by a spring 37. A limit switch 38 is mounted in a position such that it is actuated by the plate 18 when the latter is moved into its operative position. This limit switch is so connected in control circuits of the machine that movement of the carriers 12 and 13 about the axis 14 is prevented whilst the plate 18 is in its operative position.

Turning now to the arrangement of the carrier -12 which is illustrated in Figure 2, this comprises a main carrier body 41 which is connected with a pillar 42 for movement relative thereto about the axis 14, the pillar being rigidly secured to the base 6. For receiving the bearing 11, the body 41 is formed with a recesss defined by a semi-cylindrical surface 43. One end of a link 44 is hingedly connected with the body 41 and the opposite end of the link 44 is hingedly connected with a further link 45, the hinge axes being parallel to the axis 14. As shown in Figure 2, a free end portion of the link 45 can be releasably clamped to the body 41 at a position above the recess therein by a damping device 46. The links 44 and 45 present part-cylindrical surfaces which when the link 45 is clamped to the body 41 form with the surface 43 a substantially continuous cylindrical surface which embraces the bearing 11. As shown in Figure 1, when the clamping device 46 is released from the link 45, the links 44 and 45 and the clamp 46 can be moved away from the bearing 111 to permit the bearing to be withdrawn from the recess in the body 41.

The damping device 46 comprises a fork 47 having two parallel limbs which are connected together by a pivot pin 48. The pin extends through apertures in the limbs of the fork adjacent to corresponding ends of those limbs and is rigidly secured to the fork. The ends of the limbs remote from the pivot pin 48 are rigidly connected together by a block 49 in which there is formed a screw threaded bore.

A screw 50 can be screwed along this bore to engage the free end portion of the link 45 and clamp same to the body 41 in the manner shown in Figure 2.

The pivot pin 48 extends through a bore formed in the carrier body 41. This bore is intersected by a cross bore 51 in which a plunger 52 is mounted for sliding movement along the cross bore. The plunger has a larger diameter portion 53 which is a sliding fit in the cross bore 51 and a smaller diameter portion 54. An end portion 55 of the plunger protrudes from the cross bore 5-1 towards the pillar 42. On the pillar there is provided an adjustable stop 56 which is engageable with the end portion 55 of the plunger when the carrier 12 is moved to the uppermost position illustrated in Figures 1 and 2.

When the carrier is moved towards this position, but before the uppermost position is reached, the stop 56 engages the end portion 55 and thereby prevents further movement of the plunger 52 about the axis 14. Continued movement of the carrier body 41 into its uppermost position results in the pivot pin 48 being brought into a position underlying the smaller diameter portion 54 of the plunger.

This smaller diameter portion is just clear of the pivot pin 48 so that rotation of the pivot pin and of the fork 47 is not impeded.

A spring 57 which is disposed within the larger diameter portion 53 of the plunger 52 and bears against the blind end of the cross bore 51 urges the plunger along the cross bore in a direction away from the blind end thereof towards a locking position (not illustrated) in which the larger diameter portion 53 lies directly above the pivot pin 48. Movement of the plunger along the cross bore under the action of rhe spring 47 is limited. There is formed in the pivot pin 48 to receive the larger diameter portion 53 of the plunger a partcylindrical groove which is presented towards the cross bore 51 only when the fork 57 is in the position shown in Figure 2 in which the link 45 can be clamped to the body 41. During use of the machine to bend metal plate, the larger diameter portion 53 of the plunger occupies this groove and so prevents separation of the bearing 11 from the carrier 12 even if the screw 50 is withdrawn from the link 45.

The bearing can be removed from the carrier only after the carrier has been moved into its uppermost position to cause relative movement of the plunger 52 and carrier body 41 to the position shown in Figure 2. If the carrier 12 is moved to its uppermost position but the carrier 13 is somewhat below its uppermost position so that the bending roll 8 is tilted, the marginal portion 25 of the guide element 24 remains partly within the groove 26 so that the stop member 22 cannot be moved away from the periphery of the roller 17. This prevents the bending roll 8 being pivoted about the axis 15 to its discharge position until the carrier 13 also is moved to its uppermost position.

Whilst we prefer to mount the roller 17 on a part of the bending roll 8 which is integral with that part of the bending roll extending between the bearings 10 and 11, it would be within the scope of the invention for the roller to be mounted on a structurally separate extension incorporated in the bending roll and rigidly secured to that part of the bending roll which extends between the bearings.

WHAT WE CLAIM IS: 1. A machine of the kind specified compris ing an abutment for exerting a downwards force on an end portion of the bending roll remote from the discharge end thereof wherein the abutment is movable between an inopera tive position and a sole operative position with respect to the bending roll, the abutment exerting said force on the roll only when the abutment is in its operative position and said end portion is in the limit position which it occupies when the bending roll is at the limit of its travel in a direction away from the gap between the support rolls and the bending roll axis is parallel to the support roll axes.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. connected in control circuits of the machine that movement of the carriers 12 and 13 about the axis 14 is prevented whilst the plate 18 is in its operative position. Turning now to the arrangement of the carrier -12 which is illustrated in Figure 2, this comprises a main carrier body 41 which is connected with a pillar 42 for movement relative thereto about the axis 14, the pillar being rigidly secured to the base 6. For receiving the bearing 11, the body 41 is formed with a recesss defined by a semi-cylindrical surface 43. One end of a link 44 is hingedly connected with the body 41 and the opposite end of the link 44 is hingedly connected with a further link 45, the hinge axes being parallel to the axis 14. As shown in Figure 2, a free end portion of the link 45 can be releasably clamped to the body 41 at a position above the recess therein by a damping device 46. The links 44 and 45 present part-cylindrical surfaces which when the link 45 is clamped to the body 41 form with the surface 43 a substantially continuous cylindrical surface which embraces the bearing 11. As shown in Figure 1, when the clamping device 46 is released from the link 45, the links 44 and 45 and the clamp 46 can be moved away from the bearing 111 to permit the bearing to be withdrawn from the recess in the body 41. The damping device 46 comprises a fork 47 having two parallel limbs which are connected together by a pivot pin 48. The pin extends through apertures in the limbs of the fork adjacent to corresponding ends of those limbs and is rigidly secured to the fork. The ends of the limbs remote from the pivot pin 48 are rigidly connected together by a block 49 in which there is formed a screw threaded bore. A screw 50 can be screwed along this bore to engage the free end portion of the link 45 and clamp same to the body 41 in the manner shown in Figure 2. The pivot pin 48 extends through a bore formed in the carrier body 41. This bore is intersected by a cross bore 51 in which a plunger 52 is mounted for sliding movement along the cross bore. The plunger has a larger diameter portion 53 which is a sliding fit in the cross bore 51 and a smaller diameter portion 54. An end portion 55 of the plunger protrudes from the cross bore 5-1 towards the pillar 42. On the pillar there is provided an adjustable stop 56 which is engageable with the end portion 55 of the plunger when the carrier 12 is moved to the uppermost position illustrated in Figures 1 and 2. When the carrier is moved towards this position, but before the uppermost position is reached, the stop 56 engages the end portion 55 and thereby prevents further movement of the plunger 52 about the axis 14. Continued movement of the carrier body 41 into its uppermost position results in the pivot pin 48 being brought into a position underlying the smaller diameter portion 54 of the plunger. This smaller diameter portion is just clear of the pivot pin 48 so that rotation of the pivot pin and of the fork 47 is not impeded. A spring 57 which is disposed within the larger diameter portion 53 of the plunger 52 and bears against the blind end of the cross bore 51 urges the plunger along the cross bore in a direction away from the blind end thereof towards a locking position (not illustrated) in which the larger diameter portion 53 lies directly above the pivot pin 48. Movement of the plunger along the cross bore under the action of rhe spring 47 is limited. There is formed in the pivot pin 48 to receive the larger diameter portion 53 of the plunger a partcylindrical groove which is presented towards the cross bore 51 only when the fork 57 is in the position shown in Figure 2 in which the link 45 can be clamped to the body 41. During use of the machine to bend metal plate, the larger diameter portion 53 of the plunger occupies this groove and so prevents separation of the bearing 11 from the carrier 12 even if the screw 50 is withdrawn from the link 45. The bearing can be removed from the carrier only after the carrier has been moved into its uppermost position to cause relative movement of the plunger 52 and carrier body 41 to the position shown in Figure 2. If the carrier 12 is moved to its uppermost position but the carrier 13 is somewhat below its uppermost position so that the bending roll 8 is tilted, the marginal portion 25 of the guide element 24 remains partly within the groove 26 so that the stop member 22 cannot be moved away from the periphery of the roller 17. This prevents the bending roll 8 being pivoted about the axis 15 to its discharge position until the carrier 13 also is moved to its uppermost position. Whilst we prefer to mount the roller 17 on a part of the bending roll 8 which is integral with that part of the bending roll extending between the bearings 10 and 11, it would be within the scope of the invention for the roller to be mounted on a structurally separate extension incorporated in the bending roll and rigidly secured to that part of the bending roll which extends between the bearings. WHAT WE CLAIM IS:

1. A machine of the kind specified compris ing an abutment for exerting a downwards force on an end portion of the bending roll remote from the discharge end thereof wherein the abutment is movable between an inopera tive position and a sole operative position with respect to the bending roll, the abutment exerting said force on the roll only when the abutment is in its operative position and said end portion is in the limit position which it occupies when the bending roll is at the limit of its travel in a direction away from the gap between the support rolls and the bending roll axis is parallel to the support roll axes.

2. A machine according to Claim 1 wherein

a bearing which supports the bending roll at a position remote from its discharge end is arranged to permit pivoting of the bending roll from a working position to a discharge position about a pivot axis which passes through or adjacent to said bearing, the axis of the bending roll remaining parallel to a plane containing the axes of the support rolls during the pivoting of the bending roll and the machine comprising pivot control means which prevents movement of the bending roll about the pivot axis from the working position unless the abutment is in its operative position and said end portionofthe bending roll is in the limit position.

3. A machine according to Claim 2 wherein the pivot control means is arranged to maintain the abutment in its operative position whilst the bending roll is out of its working position.

4. A machine according to Claim 3 wherein there is provided a single operating member for use by an operator to move the abutment between its operative and inoperative positions and to operate the pivot control means.

5. A machine according to any preceding claim comprising bending roll adjusting means for moving the bending roll towards and away from the gap beteen the support rolls and means to prevent operation of said adjusting means when the abutment is in the operative position.

6. A machine according to any preceding claim wherein a bearing which releasably supports the bending roll at a position adjacent to the discharge end thereof is releasably supported by a carrier, the bearing being separable from the carrier only when the bearing is at the limit of its travel in a direction away from the gap between the support rolls.

7. A machine according to Claim 1 wherein a bearing which supports 'the bending roll at a position remote from its discharge end is arranged to permit pivoting of the bending roll from a working position to a discharge position about a pivot axis which passes tough or adjacent to said bearing, the axis of the bending roll remaining parallel to a plane containing the axes of the support rolls during pivoting of the beading roll, and the machine further comprising means which constrains the abutment against movement from its operative position to its inoperative position whilst the bending roll is in its discharge position.

8. A machine of the kind specified substantially as herein described with reference to and as shown in the accompanying drawings.