WO2012019220A1

WO2012019220A1 - A sheet support assembly

Info

Publication number: WO2012019220A1
Application number: PCT/AU2011/000999
Authority: WO
Inventors: Paul Robert Mccleary
Original assignee: Paul Robert Mccleary
Priority date: 2010-08-13
Filing date: 2011-08-05
Publication date: 2012-02-16

Abstract

There is firstly disclosed herein a mobile sheet support assembly including: a base having a cover to be positioned, in use, adjacent a press, the press having a hydraulic cylinder to urge a tool towards a die; a head having means to support a substantially planar sheet of material; a link assembly connecting said head to said base, said link assembly adapted to move said sheet material in a horizontal and vertical direction so that in use a portion of said sheet material is locatable between said tool and die; and a motor to move said link assembly upon operation of said press cylinder.

Description

A SHEET SUPPORT ASSEMBLY

Field of the Invention

The present invention relates to a sheet support assembly and in particular to a method and apparatus for supporting a sheet of material to be bent by a sheet folding (press) machine or the like.

Background of the Invention

It is common for solid sheets of material such as steel sheets, aluminum sheets, polymer sheets or the like to be bent or folded to a particular shape. When folding large or heavy sheets of material, for example, numerous operators are required to support the sheet while being folded and then take all the weight of the sheet after folding as it is brought back to a level plane. The operators will typically need to support the sheet in both vertical and horizontal directions. Such support can cause serious arm, shoulder and back injuries to the operators.

Accordingly, powered machines have been developed incorporating a scissor mechanism or the like to assist the operator by supporting some of the weight of the sheet. These types of machines are typically operated via electro, hydraulic or pneumatics using positional feed-back from a CNC control or the like.

The existing lifter machines have a number of disadvantages. For example, some lifters require a rail to be fitted to the press machine to support the lifter. This means that unless the press was designed for a lifter, it cannot be retrofitted as most presses do not have a clear face to slide a lifter. Also, lifters that are controlled via their own CNC have a lot of wiring to connect to the press on set up. This significantly complicates assembly and inhibits the lifter being moved between presses or other machines located around a factory floor.

Many existing lifters are also limited by their weight and large size capacity. If the thickness or size of the sheet material increases, many lifters would not operate.

A number of existing lifters also have a follower support plate which drags (slides) on the sheet material. This causes scratches as it is not pivoting around the die point, but set back from the true pivot point. Because of this, the material being supported is not synchronized with the folding press machine and causes the material to not be controlled on the downstroke which becomes a safety concern as the material being supported jumps and moves around. Further existing lifters are large or fixed and therefore can not be easily moved about a factory or work environment.

Accordingly, there is a need for a mobile compact sheet support assembly that incorporates a simple installation and can be simply moved between machines.

Object of the Invention

It is an object of the present invention to substantially overcome or at least ameliorate one or more of the disadvantages of the prior art, or to at least provide a useful alternative.

Summary of the Invention

There is firstly disclosed herein a mobile sheet support assembly including: a base having a cover to be positioned, in use, adjacent a press, the press having a hydraulic cylinder to urge a tool towards a die;

a head having means to support a substantially planar sheet of material;

a link assembly connecting said head to said base, said link assembly adapted to move said sheet material in a horizontal and vertical direction so that in use a portion of said sheet material is locatable between said tool and die;

a motor to move said link assembly upon operation of said press cylinder; and wherein said assembly is adapted to be moved about a surface upon which said assembly rests in use.

Preferably, including a pump operatively associated with said motor to move said link assembly.

Preferably, said link assembly includes a first arm and a second arm, the first arm having a first end pivotally attached to a link housing and a second end pivotally attached to said second arm, said second arm having a first end pivotally attached to said first arm and a second end attached to said head.

Preferably, said head is pivotally attached to said second end.

Preferably, said support means is a flat steel plate.

Preferably, said support means includes sensors.

Preferably, said second end of said first arm is pivotable about said first end. Preferably, said motor includes a motor housing substantially surrounding said link housing.

Preferably, said motor includes a hydraulic cylinder. Preferably, said motor includes a guide surrounding said cylinder and movable with respect to said cylinder.

Preferably, said motor includes a winch and cable.

Preferably, said motor includes a fixed gear slide.

Preferably, including a plate operatively associated with said guide and first arm, so that, in use, upon operation of said motor cylinder said guide contacts said plate rotating said first arm about said first end.

Preferably, said link assembly includes a third arm and a fourth arm, said third arm is pivotally connected to said fourth arm at a first end and said link housing at a second end; said fourth arm is pivotally connected to said first arm at a first end and said head at a second end.

Preferably, said second arm attaches to said head at a side remote said press and said fourth arm attaches to said head at a side adjacent said press.

Preferably, including a cylinder to move in use said link housing horizontally with respect to a floor surface.

Preferably, including a ram to move in use said motor housing vertically with respect to a floor surface.

Preferably, said motor in use is energized by receipt of fluid from said pump.

Preferably, said motor in use is energized by a battery.

Preferably, said motor in use is energized by application of an external power source.

Preferably, said pump is operated by the movement of said press tool towards and away from said die.

Preferably, the movement of the arms is governed by a distance the press tool moves towards or away from the die compressing or decompressing the pump.

Preferably, in a stored position said arms are located within said cover.

Preferably, during use a portion of said arms extend from said cover.

Preferably, said cover includes an opening through which said head and second arm can extend during use.

Preferably, including wheels securable to the base and adapted to permit movement of said assembly about said surface in use.

Preferably, wherein the assembly is 900 mm high, 300 mm wide and 700 mm long in a stored position. Brief Description of the Drawings

A preferred embodiment of the present invention will now be described, by way of an example only, with reference to the accompanying drawings wherein:

Figure 1 is a side elevation of the support assembly shown in a start position with the adjacent folding machine;

Figure 2 is a side elevation of the support assembly shown during use with the adjacent folding machine;

Figure 3 is an end elevation showing the interaction between the pump and cylinder of the present invention;

Figures 4 and 5 are side elevations of the support assembly shown without the housing;

Figure 6 is Detail B of Figure 5;

Figure 7 is Detail D of Figure 3;

Figure 8 is Detail A of Figure 4;

Figure 9 is Detail C of Figure 5;

Figure 10 is a hydraulic layout for an embodiment of the present invention; Figure 1 1 is a photograph of a support assembly of the present invention in a stored position;

Figure 12 is a side view of parts of the support assembly of Figure 1 1 ;

Figure 13 is a detailed view of parts of Figure 12;

Figure 14 is a partial parts view of the assembly of an embodiment of the present invention;

Figure 15 is an alternate partial parts view of the assembly of an embodiment of the present invention;

Figure 16 is a cut-away view of Figure 15;

Figure 17 is a side elevation of an alternate support assembly of an embodiment of the present invention; and

Figure 18 is a side elevation of an alternate support assembly of an embodiment of the present invention.

Detailed Description of the Preferred Embodiments

Referring to Figures 1 to 18 there is shown a mobile compact sheet support assembly 1 in the form of a sheet lifter or the like having a base 2 including a cover 3 to be positioned in use adjacent a press 5, folding machine, or other such manufacturing machine. The assembly 1 being adapted to be moved about a surface 100 upon which the assembly 1 rests in use. The press 5 in the preferred form would have a hydraulic press cylinder (not shown) or other motor means to urge a tool 7 held in a tool holder 8 towards a die 9 being supported by a die support 10.

The assembly 1 includes a head 12 having means 13 to support a substantially planar sheet of material 15. A link assembly 16 connects the head 12 to the base 2. The link assembly 16 is adapted to move the sheet material 15 in a horizontal and vertical direction with respect to a floor surface 100 so that a portion of said sheet material 15 in use is locatable between said tool 7 and die 9 as shown in Figure 6, for example. The link assembly 16 is moved by a motor 17 which is best seen in Figures 8 and 9. In the embodiment of Figure 1 to 16, a pump 20 (as best seen in Figures 3 and 7) is operatively associated with the motor 17 to move the sheet material 15 into and out of position between said tool 7 and die 9 upon operation of the press cylinder (not shown). In the preferred embodiment of Figures 17 and 18, as later discussed, the sheet material 15 is moved by other means. This will allow the sheet material 15 to be easily loaded and unloaded from the press 5 and bent to the required shape.

In Figures 1 to 16, the pump 20 is compressed or decompressed as the tool support 8 and die support 10 move towards or away from each other. However, the pump 20 could be located in other locations about the press 5 to obtain the necessary force load to activate the pump 20. That is, the motor 17 in use is energized by receipt of fluid from the pump 20 as best seen in Figures 3 and 10. The motor 17, however, could be energized in other ways as seen in Figures 17 and 18 discussed later. The fluid proceeds along tube 46 between the pump 20 and cylinder 40 as the tool support 8 and die support 10 move towards or away from each other.

The link assembly 16 as best seen in Figures 4 and 5 includes a first arm 30 and a second arm 32. The first arm 30 includes a first end 30A pivotally attached to a link housing 31 as best seen in Figure 12 and a second end 30B pivotally attached to the second arm 32 as best seen in Figure 13. The second arm 32 has a first end 32A pivotally attached to the first arm 30 and a second end 32B connected to the head 12. The link assembly 16 further includes a third arm 60 and a fourth arm 70. The third arm 60 is pivotally connected to the fourth arm 70 at 60B and the link housing 31 at the other end. The fourth arm 70 is pivotally connected to the first arm 30 at 70A and the head 12 at 70B. The support means 13 could include a flat plate as shown, gripping devices, suction pads or any other means to secure or support a sheet of material 15. Head 12 is preferably pivotally attached to the link assembly 16. In particular, the second arm 32 attaches to the head 12 at a side remote the press 5 (as seen in Figure 4 the right side of the head 12) and the fourth arm 70 attaches to the head 12 at a side adjacent the press 5 (as seen in Figure 4 the left side of the head 12). In the upright position the sheet material 15 will be supported in the die 9 as shown in Figure 6.

The motor 17 in the embodiment of Figures 1 to 16 includes a hydraulic cylinder 40 located within a motor housing 33 best shown in Figure 13. The link housing 31 is substantially "U" shaped with a flat base extending from each bottom side 51. A cylinder 81 (or other means of motion) is located below the bottom side 51 and actuated by an operator to move the link housing 31 horizontally relative to the flat surface 100. A ram 42 (or other means of motion) is located adjacent the base 2 and is adapted to move the motor housing 33 in a generally vertical direction relative to the flat surface 100.

As best seen in Figures 8, 9 and 14 the motor 17 further includes a guide 90 acting in cooperation with said cylinder 40 and movable thereto. The cylinder 40 moves the guide 90 vertically upon receipt of fluid from said pump 20. The guide 90 upon activation contacts plate 45 to pivotally rotate the first arm 30. Upon rotation of the first arm 30, the second end 30B moves vertically away from the base 2.

Referring to Figures 15 and 16 a further embodiment of the assembly 1 is shown. In this embodiment and as best seen in Figure 15 the guide 90 includes a bearing assembly 93 which is locatable within a slot 94 positioned at the first end 30A of the first arm 30. In effect therefore, the plate 45 has been replaced by a bearing assembly 93. As the cylinder 40 actuates and moves guide 90 the bearing assembly 93 moves along the slot 94 to pivot the arm 30 about the pivot end 30A. A cross section of that arrangement is shown in Figure 16.

As best seen in Figure 1 , in a stored position the arms 30, 32, 60, 70 are located substantially within the cover 3. You will note that in the embodiment shown there are two covers 3. Any number of covers 3 could be utilized. This provides a safe working environment. During use, a portion of one or more of the arms 30, 32, 60, 70 extend from the covers 3. To facilitate such movement the main cover 3 secured to the base 2 includes an opening 68 through which the head 12 and second arm 32 can extend during use.

In use, the movement of the arms 30, 32, 60, 70 in the embodiment of Figures 1 to 16 is governed by the distance the tool 7 (or tool support 8) moves towards the die 9 (or die support 10) compressing or decompressing the pump 20. The present invention 1 therefore in use utilises a linkage assembly 16 where one of the arms 30, 32, 60, 70 is used to control movement of the sheet material 15 about a pivot 80. The cylinder 40 moves a guide 90 vertically (either by way of plate 45 or bearing assembly 93) which pivots and lifts the arm 30 about pivot point 30a, by the distance that the guide 90 travels. The guide 90 travel distance is controlled by the distance that the folding press machine 5 has travelled into or out of the die 9 shown on Figure 6 as X. This distance is translated by movement of the cylinder 40 and thereby guide 90. The edge 71 of the die 9 is where the sheet material 15 is bent around and forms the pivot 80. The first arm 30 is set to this same distance of the pivot point 80 of the die 9. If the folding press machine 5 moves 10 mm down, so does the guide 90 by the same amount. It should be noted that the hydraulic control system could be replaced with other linear motion devices that operate along the same principle. For example, pneumatic control similar to the above, a mechanical pivot or linear motion to replicate motion or an electrical means using motors which are synchronized or the like as shown in the later embodiments herein.

The arms 30, 32, 60, 70 are shaped as shown in the drawings to allow the link assembly 16 to come out of the opening 68 in the cover 3 to prevent operators getting fingers caught in the control mechanism and to meet OH&S requirements. Due to the design of the arms 30, 32, 60, 70 it is possible for the assembly 1 to go through an arc of 90 degrees from the horizontal. The assembly 1 is also designed to support the bent material 15 coming down back to a level plane. Point 80 shown in Figure 1 is the theoretical pivot point of the assembly 1. If the pivot point 80 is in a different location due to differences with die 9 or height of the tool 7, then the assembly 1 can be positioned prior to folding by the link housing 31 horizontally or the motor housing 33 vertically. If the folding press machine 5 only folds a little, the assembly 1 only moves a little. This is because the assembly 1 is directly controlled from the folding press machine 5. Figure 6 shows the pivot point 80 on the die 9, and the sheet material 15 prior to being bent and after being bent. The striking distance to the pivot point is shown as Y on Figure 6. The folding press machine 5 has to travel the distance X on Figure 6. In Figure 8 distance Z is set to the same distance as Y on Figure 6. When the material 15 is folded the stroke of the pump 20 is the same as the distance P on Figure 9 of the cylinder 40, and the offset distance is the same Y so the assembly 1 works in synchronisation with the folding press machine 5. The main control arm 30 now moves the same angle as the material 15 being folded. The other arms also move with the cylinder 40 movement as they are pivotally connected at one end to the first arm 30. Simply stated, the pivot point off the assembly 1 is set to pivot around the die 9 and the stroke from the folding press machine 5 governs the angle of the assembly 1 to support the material 15.

Referring now to Figure 10, the pump 20 is self primed to remove air from the circuit utilising a tank reservoir feed 90. The folding press machine 5 pushes against the pump 20 and the displaced oil goes to the cylinder 40 which moves guide 90 and the striker 45. If there is another assembly 1 the first cylinder 40 of the first assembly 1 for striker 45 is a franking cylinder 1 10 which displaces oil to another cylinder 1 10 on another assembly (not shown). A combination of any number of cylinders could be utilised. Once the down movement of the assembly 1 occurs the speed is controlled through a speed control valve 95 until such time as the oil has been displaced back to the tank 90. The maximum travel valve 96 is there to protect the assembly 1 from an over travel situation. It operates by holding the assembly 1 at maximum upward position by proportionally dumping oil back to the tank 90 until such time as the movement is back to a downward motion.

In simplistic terms, the present invention in the embodiment of Figures 1 to 16, fits any press brake, provides a greater angle of movement than other devices, utilizes a guide 90 and striking plate 45 cooperating with a pump 20 for motion. The assembly 1 includes a hydraulic actuation follower and uses no individual power source. The assembly 1 allows a safety light curtain or the like to pass through and can be easily moved between machines and about a factory as it is compact and light. The assembly pivots around a fixed point 80 in space, the weight carrying capacity exceeds most and provides safety around the assembly 1 by way of the housing 3.

Figures 17 and 18 shows another way of controlling the sheet support assembly 1 by using a pair of sensors 200, 202. When a material sheet or plate 15 is placed on the assembly 1 , a signal from the press brake or folder 5 activates the follower (assembly 1). The follower 1 does not move until the material 15 starts lifting off the support 13. The first sensor 200 measures the distance to the material 15 and outputs power to the servo motor 17 depending on distance measured. The servo motor 17 is attached to a gearbox 203 and has a winch drum 205 attached to it which raises the lower lever 30 by way of cable 210 which in turn moves the support plate 13. The speed of motion of the support plate 13 is proportional to the distance measured by sensor 200. If sensor 200 measures a small distance to the material 15 being bent, the lever 30 motion adjusts its speed to maintain a supported condition. The faster the material 15 is bent the sheet support 13 automatically adjusts its speed and rotation to suit. Once the material 15 is fully bent and thus the follower 1 is up (see Figure 5), the press 5 releases an activate signal and the sheet following device 1 brings the material 15 back to a horizontal plane at a controlled safe speed.

A second sensor 202 detects whether a piece of material 15 is placed on the sheet support 13 warrants needing supporting. If there is no material 15 placed over the second sensor 202, then the sheet follower 1 does not activate during folding.

In another embodiment the means of motion for the main movement of the sheet support assembly 1 is provided by a gear 250 that is fixed to the side of the base 2, with a servo motor 17 and gearbox 203 climbing up the fixed gear 250. Upon obtaining the activate signal, if the sheet following device 1 is attached to a modern press brake or folder 5 that has a software switch within it's own control, this signal is used to make the sheet follower 5 active or not.

In another embodiment the activate signal is obtained by placing a roller switch, proximity switch or similar (not shown) that becomes active when the press brake or folder 5 reaches the pinch point. The pinch point is the ideal place to have the sheet follower's 5 active as the material 15 being bent is fixed between the tooling of the machine and thus the operator can not move the material 15 being bent. This switch as described is placed on a slide (not shown) where when the switch is under tension during the down stroke of the press brake or folder 5. Once the upward motion of the press 5 occurs the switch is released and thus the sheet follower 1 looses the activate signal, so that the sheet follower 1 brings the sheet material 15 down. Thus, it is activated like the pump of Figures 1 to 16.

Yet another way of obtaining an activate signal is to use a relay lock (not shown). From the press brake or folder 5 we need a signal at the mute point or pinch point. All press brakes 5 have a mute point as it is used to turn off the light guards protecting the press brake or folder 5 from the operator. The signal is taken and sent through a locking relay. This locking relay signal is sent to the sheet follower 1 as the activate signal. This locking relay is de-activated when the up relay is activated.

Obviously the above could be done with switches mounted to the press brake or folder 5, via a PLC or the like.

Another means of control is to not use the sensor 200, but control the sheet follower 1 by following the same angle as that of the press brake or folder 5. To make the sheet follower 1 work when materials 15 cannot be measured by sensor 201 , we need to control the follower 1 in a different way. We need to take from the press beam 8 the linear signal of the downward movement. This can be a LVDT (linear variable differential transformer) or similar. In the example of the LVDT, we receive a variable voltage depending on the position of the press beam 8. We can use sensor 202 as the activate signal, where the material 15 being supported lifts off the sheet follower device 1. At this point we take the LVDT voltage and run a calculation through a PLC, PC or the like to convert this linear measurement to an angular motion. Sensor 202 during the motion can be used to confirm the speed set to the servo 203 is either too fast or too slow. Once the LVDT changes direction the servo 203 controls the sheet follower 1 to bring the bent material 15 down in a controlled manner.

If a gap occurs between the sheet follower 1 and the material 15 being supported in the upward motion it is of no great concern as the press brake or folder 5 is supporting the material 15. When coming down we need control of the support 13, as the press brake or folder 5 cannot do a controlled move down with the bent material 15.

Another means of control is to take the press beam 8 movement (which is linear) and transpose this to a dummy lever (not shown). This could be done electrically or mechanically via a push-pull cable (not shown). The dummy lever would move through the same arc as the sheet follower device 1. Attached to the dummy lever at it's pivot is a rotary encoder (not shown) which moves the sheet follower device 1 by follower control. (If an encoder moves 10 degrees so does the servo 203). The feedback for the servo motor 203 is not placed on the motor 17 which is typical but actually on the main lower pivot 30a within the sheet follower device 1. The motion of the sheet follower device 1 would be as described above.

Another means of control is to have a linear encoder mounted on the press beam 8 and another mounted on the lower lever 30 inside the sheet follower device 1 (where the hydraulic cylinder 81 was fitted previously). Again the servo motor 203 feedback would come from the linear encoder.

Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms. For example, the assembly 1 can include one or more link assemblies 16. In Figure 13 two link assemblies are shown side-by-side having two sets of arms 30, 32, 60, 70. The base 2 could be located on wheels (not shown), tracks (not shown) or the like to move the assembly 1 about the surface 100. A brake (not shown), stop means or the like could be utilised to stop the assembly 1 moving relative to the surface 100. The assembly 1 could also include one or more parts being automated or programmable by an operator. In the preferred form the assembly 1 is compact having a size of 900 mm high, 300 mm wide and 700 mm long in the stored position. Upon expansion the assembly 1 extends to 1200 mm high, 300 mm wide and 800 mm long. In another embodiment, the assembly 1 would proportionably be a little larger however will always remain compact. The assembly 1 could also include over travel stops 75 as shown in Figure 12 or the like. The motors 17 could be energized by any means including manual, a pump, battery, solar, external mains power supply or the like.

Claims

CLAIMS:

1. A mobile sheet support assembly including:

a base having a cover to be positioned, in use, adjacent a press, the press having a hydraulic cylinder to urge a tool towards a die;

a head having means to support a substantially planar sheet of material;

a link assembly connecting said head to said base, said link assembly adapted to move said sheet material in a horizontal and vertical direction so that in use a portion of said sheet material is locatable between said tool and die; and

2. The sheet support assembly according to claim 1 , including a pump operatively associated with said motor to move said link assembly.

3. The sheet support assembly according to claim 1, wherein said link assembly includes a first arm and a second arm, the first arm having a first end pivotally attached to a link housing and a second end pivotally attached to said second arm, said second arm having a first end pivotally attached to said first arm and a second end attached to said head.

4. The sheet support assembly according to claim 1 , wherein said head is pivotally attached to said second end.

5. The sheet support assembly according to claim 1, wherein said support means is a flat steel plate.

6. The sheet support assembly according to claim 1 , wherein said support means includes sensors.

7. The sheet support assembly according to claim 1, wherein said second end of said first arm is pivotable about said first end.

8. The sheet support assembly according to claim 1, wherein said motor includes a motor housing substantially surrounding said link housing.

9. The sheet support assembly according to claim 1, wherein said motor includes a hydraulic cylinder.

10. The sheet support assembly according to claim 1 , wherein said motor includes a guide surrounding said cylinder and movable with respect to said cylinder.

1 1. The sheet support assembly according to claim 1 , wherein said motor includes a winch and cable.

12. The sheet support assembly according to claim 1, wherein said motor includes a fixed gear slide.

13. The sheet support assembly according to claim 1 , including a plate operatively associated with said guide and first arm, so that, in use, upon operation of said motor cylinder said guide contacts said plate rotating said first arm about said first end.

14. The sheet support assembly according to claim 1, wherein said link assembly includes a third arm and a fourth arm, said third arm is pivotally connected to said fourth arm at a first end and said link housing at a second end; said fourth arm is pivotally connected to said first arm at a first end and said head at a second end.

15. The sheet support assembly according to claim 1, wherein said second arm attaches to said head at a side remote said press and said fourth arm attaches to said head at a side adjacent said press.

16. The sheet support assembly according to claim 1, including a cylinder to move in use said link housing horizontally with respect to a floor surface.

17. The sheet support assembly according to claim 1, including a ram to move in use said motor housing vertically with respect to a floor surface.

18. The sheet support assembly according to claim 1, wherein said motor in use is energized by receipt of fluid from said pump.

19. The sheet support assembly according to claim 1 , wherein said motor in use is energized by a battery.

20. The sheet support assembly according to claim 1 , wherein said motor in use is energized by application of an external power source.

21. The sheet support assembly according to claim 1 , wherein said pump is operated by the movement of said press tool towards and away from said die.

22. The sheet support assembly according to claim 1 , wherein the movement of the arms is governed by a distance the press tool moves towards or away from the die compressing or decompressing the pump.

23. The sheet support assembly according to claim 1, wherein in a stored position said arms are located within said cover.

24. The sheet support assembly according to claim 1, wherein during use a portion of said arms extend from said cover.

25. The sheet support assembly according to claim 1, wherein said cover includes an opening through which said head and second arm can extend during use.

26. The sheet support assembly according to claim 1, including wheels securable to the base and adapted to permit movement of said assembly about said surface in use.

27. The sheet support assembly according to claim 1, wherein the assembly is 900 mm high, 300 mm wide and 700 mm long in a stored position.