GB2227199A

GB2227199A - A machine with driven tool support

Info

Publication number: GB2227199A
Application number: GB8918038A
Authority: GB
Inventors: Roger Henry Regan; Kevin John Geraghty
Original assignee: PROFILE CUTTING MACHINES LIMIT
Current assignee: PROFILE CUTTING MACHINES LIMIT
Priority date: 1988-08-06
Filing date: 1989-08-07
Publication date: 1990-07-25
Also published as: GB8818718D0; GB8918038D0

Abstract

A machine comprises a slide 17 on one end of which is supported a tool such as a flame cutting tool 23 and main slideway 11. The slide 17 is movable by a stepper motor 20 in a direction transverse to the main slideway 11 and is movable along the main slideway 11 by a stepper motor 14. The stepper motors 14, 20 ensure that movement of the flame cutting too, is vibratory which results in a smoother finish to the cut. The slide 17 is demountable from the slideway 11 and can be arranged alongside the main slideway 11 which includes a carrying handle 15 at each end such that the entire machine can be lifted for transport or storage in a compact form. Pipework 25 is provided for feeding suitable gases to the flame cutting tool 23 and a supply is thus simply connected to the machine at one end of the main slideway 11. <IMAGE>

Description

A M HINZ The invention relates to a machine and is particularly, but not exclusively concerned with a flame cutting machine.

With prior flame cutting machines, problems have arisen with the production of a smooth cut which, to a certain extent are due to the way in which the flame is moved over the material being cut. If the flame nozzle is moved at a slow steady speed then the flame tip will tend to stick? in a position until the flame nozzle has moved a certain distance further on when it will jump to catch up with the steadily moving nozzle. One object of the present invention is to provide a machine which is suitable for flame cutting and which provides a smoother cut.

According to one aspect of the invention there is provided a tool, a workpiece and drive means for moving one of the tool and workpiece relative to the other, the drive means being arranged to impart drive in a vibratory or pulse-like manner.

According to another aspect of the invention, there is provided a machine comprising a support for a tool which is movable by drive means, the drive means being arranged to impart drive to the support in a vibratory or pulse-like manner.

Where the machine is of a flame cutting type, the pulsating drive has been found to provide a smoother form of cut thereby avoiding the disadvantages of the prior machines.

The drive means may include a stepper motor.

Preferably, the drive means transmits its drive to, e.g., the support through a backlash-free transmission such as a reduction gear. The reduction gear may include a rack and pinion system.

The support may include a slide which is mounted in a slide nay for, e.g., linear movement by the drive means. Preferably the slide is movable in the slideway on a linear bearing to reduce any stress on the drive means.

The support may be arranged to carry a tool in the at one end. The tool may be a flame cutting head or e.g., a plasma cutter.

The support may comprise a first support of an arrangement comprising first and second supports, the first support being movable by the drive means in one direction and the second support being movable in a transverse direction on the second support.

The movement of the first support along the second support means may be effected by a second drive means which, again, preferably transmits drive thereto in a pulse-like or vibratory manner. The second drive means preferably includes a stepper motor type which may transmit its drive through a backlash free transmission such as a reduction transmission. The transmission may include a rack and pinion system.

Cutting machine are known in which a cutting tool is mounted on an elongate support which is movable in a slideway by a drive motor, the elongate support being movable transversely on a transversely arranged slide. The transversely arranged slide is mounted on a cutting bed in the form of a large rectangular framework with cross pieces on which a workpiece can be supported so that it can be cut.

According to a further aspect of the invention, there is provided a machine comprising a first support for a tool and a second support, the first support being movable by first drive means in one direction and the first support being movable in a transverse direction on the second support, the first support being demountable from the second support such that the first support can be arranged along the side of the second support.

In this way, the machine can be compactly stowed away when it is not in use and the framework for supporting workpieces can be used for other purposes or partially dismantled.

The first support preferably includes a slide which is mounted in a slideway for movement in said one direction and the first support may be demountable from the second support by removal of the slide from the slideway Preferably, a removable stop is provided for preventing accidental removal of the slide from the slideway.

The first support is preferably arranged to be secured to the second support so that the machine is portable and thus can be removed from a cutting bed.

Preferably, handles are provided adjacent each end of the second support and the machine is sufficiently light that it can be lifted by two people.

The machine need not be used with a cutting bed but preferably is arranged to be secured to a cutting bed, for example, by clamps, in use.

In the known flame cutting machine described, the flame cutting tool on the elongate support is eupplied with gas for burning via flexible tubes which commonly extend from the supply up to a position above the machine, e.g., in the rafters of a workshop and dawn from a position substantially above the tool to the tool itself The lines must therefore be arranged carefully before use of the tool to ensure that they can be pulled to the furthest position in which the tool should cut and to ensure that they will not become caught in the machine.

According to a still further aspect of the invention, there is provided a machine comprising a first support for a flame cutting tool and a second support, the first support being movable by first drive means in one direction and the first support being movable in a transverse direction on the second support, and supply lines for supplying gas between the tool and connectors for connecting the supply lines to a supply, the connectors being provided on t part of the machine which is static in use.

In this way. a supply can simply be connected to the machine and the machine is ready for use.

The connectors may be provided in any suitable position but preferably are provided on the second support, for example, at one end o the second support. Preferably, the supply lines are prevented from becoming caught in the machine by guide means.

The guide means in relation to the first support may comprise a guide channel and in relation to the second support may comprise a cable chain.

Where the machine is in the form of a flame cutting machine. the flame may be arranged to cut the predetermined pattern in a particular material and another object of the invention is to provide a device suitable for following the pre-determined pattern to enable the tool to be guided appropriately.

According to yet another aspect of the invention there is provided a device for sensing a path comprising means for effecting relative movement between a sensor and the path, the sensor including means for sensing portions of the path during said relative movement, and control means for controlling the means for effecting said relative movement in response to a signal resulting from the sensing of said path.

Preferably, the sensor is arranged to ionic portions of the path and an area immediately adjacent the path, Preferably, the sensor is arranged to sense the portions of the path and the area immediately adjacent the path alternately.

Where the sensor senses portions of the path and the area Immediately adjacent the path the sensor is able to produce different signals which can be utilised to determine the position of the sensor in relation to the path.

The sensor may include means for receiving a signal reflected from the portions of the path sensed or, in the case where the sensing means senses portions of the path and an area immediately adjacent the path, the sensor receives signals reflected from the path and the said area. Preferably, the signals are light signals which may be produced by a light source directed towards the path.

Focusing means may be arranged to receive the reflected signals and focus them onto the sensor.

Where the signals are derived from a light source, the focusing means may be a lens.

The focusing means may be arranged for rotation in such a way that it focuses the signals from the portions of the pzth and the immediately adjacent area alternately on the sensor.

Means may be provided for effecting relative movement between a tool and a workpiece in response to the relative movement between the sensor and the path.

If desired, the relative movement between the path and the sensor is recorded in a memory device which can be used subsequently to control the relative movement between the tool and the workpiece to enable repeated patterns to be followed by the tool.

The tool may be arranged in a machine in accordance with the first aspect of the invention.

A machine in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which: Fig.1 is a schematic perspective view of a flame cutting machine in accordance with the invention, Fig.2 is a schematic view of a sensing arrangement for sensing a path to be followed by a flame cutting head of the machine in Fig.1, Fig.3 is a plan view of a path in the form of a letter V.

A main slideway 11 is supported on a base 10 having main slideway 11 (constituting the aforesaid second support) thereon. The slideway includes spaced rails 12 and a rack 13 in mesh with a pinion (not shown) of a drive 14. The main slidoway 11 is provided with handles 15 at its end. to enable it to be lifted off the base and carried to another location.

The main slideway 11 supports an auxiliary slideway 16 on which is slidably mounted a slide 17 constituting the aforesaid first support means. The slide 17 is provided with a rack 18 which meshes with a pinion 19 drivable by a stepper motor 20 through a backlash-free transmission indicated generally at 22.

The drive 14 is of a similar construction.

The slide 17 supports a flame cutting head 23 at one end which is directed downwardly towards the base 10 which is used to support a suitable workpiece 24, e.g., a steel plate. Pipework 25 is provided for feeding suitable gases to the flame cutting head.

Conveniently, part of the pipework is housed within a channel 26 along the upper edge of the slide 17 and from there it passes, in part, through a cable chain 27. The cable chain runs parallel with the main slideway 11 and the pipework therein is connected to inlets 28 at one end of the main slideway.

The stepper motors for driving the auxiliary slideway 16 and slide 17 are preferably controlled by a programmable control device (not shown) which enables the flame cutting head 23 to be moved in a desired manner The stepper motors effect a pulsing or vibratory motion to the auxiliary slideway 16 and the slide 17 which causes the flame cutter to produce a very smooth cut in the workpieee 24.

If desired, the path to be followed by the flame cutting head can be entered into the memory of the programmable device by using a sensing device shown schematically in Fig.2. The sensing device can be attached to the slide 17 and a suitable pattern to be followed, e.g., the letter V as shown in Fig.3, placed on the base 10. The sensing device comprises a mounting 29 for attachment to the slide 17, a light beam sensor 30 on the mounting and a lens 32 which is inclined and mounted for rotation on the mounting 29 by means of a motor 33 via a transmission 34.

As shown in Fig.3, a light source 35 is arranged to direct light onto the pattern indicated at 36 and the lens 32 is arranged to focus reflected light onto the sensor 30.

The sensor 30 is arranged over an edge of the pattern 36 such that when the lens 32 is rotated, the sensor 30 will detect alternate portions 36a of the pattern 36 and 37a of an irmediately adjacent area 37. The contrast between the two areas 36a, 37a may be improved by arranging the pattern 36 on a sheet of material of substantially different colouring from that of the pattern.

Output from the sensor 30 is used to control the stepper motors of the drives to move the senior relative to the pattern. Provided that the sensor 30 detects a constant ratio between the light reflected from the portions 36a, 37 during movement, the sensor is following the edge of the pattern.

However, any change in the ratio will provide an indication that the sensor is moving off course and the ratio change will be used to control either or both stepper motors to bring the sensor back on course so as to follow the pattern precisely. All of the movements of the stepper rotors are recorded by the programmable device so that when the pattern has been fully scanned, the complete movement will be recorded in the memory device to enable the flame cutting head 23 subsequently to cut the material to that shape.

If desired, the programmable device may be arranged with a simple to operate control member such as a joystick to enable the stepper motors to be controlled manually which may be useful in certain situations.

The programmable device may also be programmed to provide simple shapes on the entering of certain information. For example the device may be programmed to cut a circle given the intended centre point and a point on the circumference. Also, if a required spacing between two such shapes is entered the device may be programmed to repeat the shape at that spacing.

The invention is particularly useful in that its portability enables it to be used in locations where it would be virtually impossible to place known types of profile cutting machines which are large and nonportable. For example, the machine could be transported easily for use on a building site1 bridge, ship or the like without any difficulty. Ease of portability is increased by detaching the auxiliary slideway 16 from the main slideway 11.

Claims

1. A machine comprising a support for a tool which is movable by drive means, the drive means being arranged to impart drive to the support in a vibratory or pulse-like manner.

2. A machine as claimed in Claim I, wherein the drive means includes a stepper motor.

3. A machine as claimed in Claim 1 or 2, wherein the drive means transmits its drive to the support through a backlash-free transmission.

4. A machine as claimed in Claim 3, wherein the transmission is a reduction gear.

5. A machine as claimed in Claim 4, wherein the reduction gear includes a rack and pinion system.

6. A machine as claimed in any preceding Claim, wherein the support includes a slide which is mounted in a slide way for movement by the drive means.

7. A machine as claimed in Claim 6, wherein the slide is movable in the slideway on a linear bearing.

8. A machine as claimed in any preceding Claim, wherein the support is arranged to carry a tool at one end.

9. A machine as claimed in any preceding Claim wherein the support comprises a first support of an arrangement comprising first and second support, the first support being movable by the drive means in one direction and the first support being movable in a transverse direction on the second support.

10. A machine as claimed in Claim 9, wherein the movement of the first support means along the second support means is effected by a second drive means which is arranged to input drive thereto in a pulselike or vibratory manner.

11. A machine as claimed in Claim 10, wherein the second drive means includes a stepper motor.

12. A machine as claimed in Claim 11 wherein the second drive means transmits its drive to the second support through a backlash free transmission.

13. A machine as claimed in Claim 12, wherein the transmission is a reduction gear.

14. A machine as claimed in Claim 13, wherein the reduction gear includes a rack and pinion system.

15. A machine as claimed in any of Claims 9 to 14 wherein the first support is demountable from the second support such that the first is demountable from the second support such that the first support can be arranged alongside the second support.

16. A machine comprising a first support for a tool and a second support, the first support being movable by first drive means in one direction and the first support being movable in a transverse direction on the second support, the first support being dcmountable from the second support such that the first support can be arranged alongside the second support.

17. A machine as claimed in Claim 15 or Claim 16, wherein the first support includes a slide which is mounted in a slideway for movement in said one direction and the first support is demountable from the second support by removal of the slide from the slideway.

18. A machine as claimed in Claim 17, wherein a removable step is provided for preventing removal of the slide from the slidoway.

19. A machine as claimed in any of Claims 15 to 18, wherein the first support is arranged to be secured to the second support so that the machine is portable.

20. A machine as claimed in Claim 19, wherein handles are provided adjacent each end of the second support.

21. A machine as claimed in any of Claims 9 to 20, wherein the machine is arranged to be secured to a cutting bed for support a workpiece for use.

22. A machine as claimed in Claim 21, wherein clamps are provided for securing the machine to a cutting head.

23. A machine as claimed in any of Claims 9 to 22, wherein the tool is a flame cutting tool.

24. A machine as claimed in Claim 23, wherein the machine includes supply lines for supplying gas between the tool and connectors for connecting the supply lines to a supply, the connections being provided on a part of the machine which is static in use.

25. A machine comprising a first support for a flame cutting tool and a second support, the first support being movable by a first drive weans in one direction and the first support being movable in a transverse direction on the second support, and supply lines for supplying gas between the tool and connectors for connecting the supply lines to a supply, the connectors being provided on a part of the machine which is static in use.

26. A machine as claimed in Claim 24 or Claim 25, wherein the connectors are provided In the second support.

27. A machine as claimed in Claim 24, 25 or 26, wherein guide means are provided for preventing the supply lines from becoming caught in the machine.

28. A machine as claimed in Claim 27, wherein the guide means in relation to the first support comprises a guide channel.

29. A machine as claimed in Claim 27 or 28, wherein the guide means in relation to the second support comprises a cable claim.

30. A machine substantially as described herein with reference to the accompanying drawings.

31. A device for sensing a path comprising means for effecting relative movement between a sensor and the path, the sensor including means for sensing portions of the path during said relative movement, and control means for controlling the means for effecting said relative movement in response to a signal resulting from the sensing of said path.

32. A device as claimed in Claim 31, wherein the sensor is arranged to sense portions of the path and an area immediately adjacent the path.

33. A device as claimed in Claim 32, wherein the sensor is arranged to sense the portions of the path and the area immediately adjacent the path alternately.

34. A device as claimed in Claim 32 or 33, wherein the sensor is able to produce different signals, from sensing portions of the path and the area immediately adjacent the path which can be utilised to determine the position of the sensor in relation to the path.

35. A device as claim in any of Claims 31 to 34 wherein the sensor receives a reflected signal.

36. A device as claimed in Claim 35, wherein the device includes focusing means arranged to receive the reflected signals and focus them onto the sensor.

37. A device as claimed in Claim 36, wherein the signals are derived from a light source, the focusing means is a lens.

38. A device as claimed in Claim 36 or 37, wherein the focusing means is arranged for rotation in such a way that it focuses the signals from the portions of the path and the immediately adjacent area alternatively on the sensor.

39. A device as claimed in any of Claims 31 to 38 wherein means is provided for effecting relative movement between a tool and a workpiece in response to the relative movement between the sensor and the path.

40. A device as claimed in Claim 39, wherein the relative movement between the path and the sensor is recorded in a memory device which can be used subsequently to control the relative movement between the tool and the workpiece to enable repeated patterns to be followed by the tool.

41. A device as claimed in Claim 39 or 40, wherein the tool is arranged in u machine as claimed in any of Claims 1 to 30.

42. A device substantially as described herein with reference to the accompanying drawings.