GB1583456A

GB1583456A - Marking of workpieces

Info

Publication number: GB1583456A
Application number: GB49015/77A
Authority: GB
Original assignee: Hoesch Werke AG
Current assignee: Hoesch Werke AG
Priority date: 1976-11-30
Filing date: 1977-11-24
Publication date: 1981-01-28
Also published as: IT1091094B; FR2372032A1

Description

(54) IMPPROVEMENTS IN OR RELATING TO THE MARKING OF WORKPIECES (71) We, HOESCH WERKE AKTIBN GESELLSCHAFT, of Eberhardstrasse 12, 4600 Dortmund, Germany, a German Company 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 particularly described in and by the following statement: The invention relates to an apparatus for marking a workpiece.

It is the general practice to mark a series of characters on large workpieces manually with paint by the use of brushes or spray guns. In the case of cold workpieces stencils are also used in the operation of applying the identifying characters. It is also known to apply numbering or lettering by means of assemblies each comprising seven guns, of which each one produces one component stroke of a character. In the event of failure of individual spray guns there is the risk that faulty characters will be applied. Added to this is the fact that the streams of colouring matter are liable to have a marked spreading effect thus rendering the characters meaningless or hardly legible. The difficulties are not eased if unitary spots are used, instead of strokes, to compose the stylized characters, or if powdered colour instead of liquid is sprayed on. Moreover the colour rapidly dries when marking hot workpieces, and not least the operating personnel are exposed to considerable heat stress.

The invention accordingly provides an apparatus for marking a workpiece with a plurality of characters, the apparatus comprising a frame mounting a stencil member having a plurality of characters formed therein and a spray nozzle operable to spray marking material, first means for moving the stencil member relative to the spray nozzle for character selection, second means for moving the stencil member and the spray nozzle together with respect to the frame into a position for marking the workpiece with a selected character, and third means for moving the frame relative to the workpiece for marking the workpiece with a selected character at a second location.

The invention can readily be embodied in apparatus by which large workpieces, such as coiled strip, slabs, castings, and the like may be rapidly and reliably marked with a series of clearly legible, sharp-edged alpha-numeric or other characters without subjecting the operation personnel to undue heat or other stress, and by which the marking can be applied not only to the curved peripheral surface of a coiled strip but also if required to the upper surface of the coil.

In a preferred apparatus embodying the invention, a first piston and cylinder unit is centrally arranged within a frame provided with wheels, and upon the piston of this piston and cylinder unit there is arranged a rising table carrying the second piston and cylinder unit. According to a further feature of this apparatus, the piston and cylinder unit, which is arranged in a cavity in the rising table, is covered by a support plate accommodating the shafts of deflecting or guide rollers. A convenient arrangement is one in which three deflecting rollers are provided at the corners of a tringle the rollers having teeth at their upper and lower peripheries meshing with perforations provided in an endless strip constituting the stencil member, one o the rollers is provided with driving means.

Advantageously there are provided, between the deflecting rollers which lie nearest to the workpiece to be marked, a colour spraying devive pivotable about a horizontal axis, and below this colour spraying device there is arranged a tank charged with a cleaning liquid. Between that deflecting roller which is provided with the driving means, and each of the two other deflecting rollers there may be located a tank filled with a cleaning liquid and provided with cleaning brushes for cleaning the stencil strip.

For the purpose of achieving precise positioning of the apparatus according to the invention with respect to the workpiece which is to be marked, it is advantageous to provide upon the support plate, and situated opposite to the workpiece, a feeler for adjusting the clearance from the workpiece, and a further feeler for adjusting the height of the colour spraying device with respect to the workpiece.

Where the apparatus is required to mark workpieces having, for example, a rounded surface, then the wheels are advantageously arranged to travel, together with the entire marking device, along a circular track, the centre point of which is defined by the centre point of the workpiece. It is of particular advantage to provide the drive for the deflecting rollers and the drive for the wheels of the marking device in each case in the form of an electrical stepping motor with a hydraulic torque amplifier.

Where in an apparatus according to the invention the stencil member has the form of a ring of angular cross-section the ring is preferably connected to a bearing pin secured upon an arm, which arm is provided with means for both lateral and height adjustment in the form of respective piston and cylinder units. The spraying nozzle is then positioned vertically above the flange portion of the angle section ring upon the outer end of the arm, and a second, horizontal, spraying nozzle is arranged on the lower end of the bearing pin, so as to be pivotable about a horizontal axis within the cylindrical portion of the angle section ring.

Furthermore means are preferably provided in the form of further piston and cylinder units for dipping the spray nozzles into tanks filled with a colour solvent medium. According to a preferred practical form of the construction the horizontal spray nozzle is arranged to be pivotally connected to the piston and cylinder unit which is connected to the bearing pin and the vertical spray nozzle is connected for up and down motion with the piston and cylinder unit, which is connected by way of a driven pivoting arm to the bearing pin.

For achieving frictionless functioning there is provided at the underside of the arm a driven cleaning brush positioned above the flange portion of the angle section ring, and a further driven cleaning brush is carried upon the bearing pin within the cylindrical portion of the angle section ring.

The adjustability of the marking apparatus relative to the workpiece to be marked is advantageously achieved by providing upon an extension of the arm projecting beyond the bearing pin, a feeler arranged to operate, through end switches, upon the piston and cylinder unit, which, by the action of its piston, controls the height adjustment, and by further feeler on an arm carried by the bearing pin arranged to operate through end switches to influence the piston and cylinder unit which effects the lateral adjustment.

The invention is further explained below by way of example with reference to the accompanying drawings, in which: Figure 1 is a side view partly in cross section of a first apparatus embodying the invention; Figure 2 is a plan view of the apparatus of figure 1; Figure 3 is a side view partly in crosssection of a second apparatus embodying the invention; and Figure 4 is a plan view of the apparatus of figure 3.

As shown in figures 1 to 4, a workpiece 2 in the form of a steel sheet wound into a coil is supported upon a conveyor 1 or the like, for example for transportation within a rolling mill from a windh to a coil storage site. A track 4 provided upon a foundation 3 extends externally of and alongside the conveyor 1 and upon this track a marking apparatus 5 described below can travel by means of driven wheels 6.

The wheels 6 are carried by a frame 7, within which there is centrally arranged a piston and cylinder unit 8, upon the piston 9 of which there is supported a lifting table 10 so that the table can be raised and lowered by the piston. The wheels 6 are driven by a driving unit 6a, seen in figures 2 and 4, which preferably comprises an electrical stepping motor with an hydraulic torque amplifier.

Also as seen in figure 1, the lifting table 10 is provided with a cavity 11, which is covered by a support plate 12. Within the cavity 11, and directed at right angles to the axis of the track 4 is a further piston and cylinder unit 13, the piston 14 of which is coupled to a skirt portion 15 of the support plate 12. Thus by operation of the piston and cylinder unit 13, the support plate 12 can be moved towards and away from the coil 2. In the marking apparatus 5 of figures 1 and 2, a feeler 16 is arranged at a point of the skirt portion 15 of the support plate 12 positioned opposite the outermost turn of the coil 2 so that when contact is made between the feeler and the coil 2 the horizontal motion of the piston 14 is arrested by means of an end switch (not shown).

In the support plate 12 there are journalled the shafts 17 of three deflecting rollers 18 situated at respective corners of an equilateral triangle, the rollers being provided at their upper and lower peripheries with teeth meshing with a cooperatingly perforated endless stencil strip 19, which passes around the rollers. The deflecting roller 18 which is situated at the greatest distance from the material to be marked, that is, the coil 2, is driven by a driving unit 20, preferably comprising an electrical stepping motor with an hydraulic torque amplifier.

Centrally arranged between the two deflecting rollers 18 which lie nearest to the coil 2, there is a spraying device 21 with a spray nozzle for spraying liquid or powdered marking material which may be coloured or black or white. The device 21 is tiltable about a horizontal axis 22.

After the completion of a marking operation the spraying device 21 is tilted about this axis 22, so that its spray nozzle is dipped, and thereby cleaned, in a tank 23 charged with cleaning liquid and arranged underneath the device.

Between the one deflecting roller 18 provided with the driving unit 20 and each of the other two deflecting rollers 18, there is provided a tank filled with cleaning liquid and having brushes 24 for cleaning the stencil strip 19.

So that the stencil strip 19, which is formed with numerals and letters, shall always remain at a constant height with respect to the upper edge of the coil 2 during its movements whilst the workpiece is being marked, a further feeler 26 is provided, which upon making contact with the upper edge of the coil 2 arrests the movement of the piston and cylinder unit 8 by means of an end switch, (not shown).

The workpiece which is advanced upon the conveyor 1, or other suitable transportation device, such as a conveyor chain or walking beam, is marked in the following manner.

The conveyor 1 operates intermittently, that is to say it is held stationary at certain time intervals, between which it advances for a predetermined time. The. coil 2 which is to be marked is always maintained with its centre at the same point "b". At the same time the stencil strip 19 is rotated through such a distance by the driving unit 20 that the desired first character is positioned opposite the spray device 21. Thereupon the spray device 21, which is positioned in alignment with the point "b" is advanced by means of the piston and cylinder unit 13 towards the coil 2 until the feeler 16 makes contact with the outermost surface of the coil and causes the movement of the piston 14 to be arrested by means of an end switch.

In a similar manner the height of the marking with reference to the upper edge of the coil 2 is adjusted by means of the piston and cylinder unit 8 and the feeler 26. The first digit or the first letter is now applied to the area of the coil 2 indicated by the reference "a" (compared figure 2), by operating the colour spray device 21, because this corresponding digit or letter in the stencil strip 19 has been brought into position opposite the spray device.

After the application of the first digit or letter, the apparatus 5 is advanced upon the curved track 4, whose centre point coincides with the centre point "b" of the coil 2, through a distance corresponding to one digit or character, whilst simultaneously the following digit or the following letter upon the stencil strip 19 is placed in front of the colour spray device 21. This operation is repeated until the entire desired sequence of digit and/or letters has been applied to the coil 2. After each marking sequence, the colour spray device 21 is lowered about the horizontal pivot axis 22 into the tank 23 and is thereby cleaned by the liquid in this tank 23. After the completion of the marking operation of the workpiece 2, the apparatus 5 returns to its starting position by travelling along the rails 4.

The marking apparatus 5 shown in figures 3 and 4 differs from the marking device 5 of figures 1 and 2 in that upon the skirt portion 15 of the support plate 12 there is secured an arm 27, in which is secured the upper end of a bearing pin 28. In a position underneath the arm 27 there is mounted upon the bearing pin 28 an angle section ring 29, having a flange portion 30 and a cylindrical portion 31.

This cylindrical portion 31 of the angle section ring 29 is provided with a series of characters 30a, in the form of perforations through the portion, which have the function of applying the required marking to the outer surface of the workpiece 2. In a similar way the flange portion 30 of the angle section ring 29 is provided at its periphery with a series of characters 30a as perforations therethrough, whereby it is also possible to apply a marking to the upper side of the coil workpiece 2.

Above the flange portion 30 of the angle section ring 29, a vertical spray nozzle 32 is positioned at the outer end of the arm 27. A horizontal spray nozzle 33 is located outside the cylindrical portion 31 of the ring and opposite the characters 30a formed therein, this nozzle being supported upon the lower end of the bearing pin 28 and arranged to be tiltable about a horizontal pivot axis 33a.

The angle section ring 29 is preferably driven by means of a gear motor 34 flanged to the arm 27 and operating through a stepping mechanism 35 so that at each revolution of the stepping mechanism 35 the angle section ring 29 is racked through a distance of one character division.

Each time a marking operation has been completed spray nozzles 32, 33 are cleaned by dipping them in respective tanks 36, 36' charged with the colour solvent medium to prevent the drying up, in or upon the spray nozzles 32, 33, of the colour used in the marking operation so that the next marking operation can begin at the required time.

For this purpose a piston and cylinder unit 37 is secured to the bearing pin 28 in a position above the spray nozzle 33, which is pivotally connected thereto, so that by pivoting about the axis 33a the spray nozzle 33 can have its aperture submerged in the tank 36'.

Likewise the spray nozzle 32 is connected to a piston and cylinder unit 38, by means of which it can be lifted and lowered. The piston and cylinder unit 38 is arranged upon a pivot arm 39, which can be swung about the bearing pin 28 by means of a driving unit 40.

After the raising of the spray nozzle 32 by means of the piston and cylinder unit 38 and swinging of the pivot arm 39 by means of the drive unit 40 located upon the arm 27, the spray nozzle 32 can be immersed in the tank 36.

For the purpose of cleaning the characters 30a formed in the flange portion 30 of the angle section ring 29, there is provided at the underside of the arm 27 a cleaning brush 42 driven by means of a motor 41 to effect the cleaning operation from above the flange portion. Likewise, for the purpose of cleaning the characters machined in the cylindrical portion 31 of the angle section ring 29, a cleaning brush 44 is provided, which is supported upon the bearing pin 28 and piston 9 of the piston and cylinder unit 8.

In a similar manner the horizontal sideways movement of the piston 14 of the piston and cylinder unit 13 is arrested through the action of a further end switch (not shown). This takes place when a further feeler 46, which is secured to an arm 47 carried upon the bearing pin 28, makes contact with the outermost turn of the coil 2.

The colouring matter used for the marking operation, which is contained in a tank 48 carried upon the arm 27, is pumped to the spray nozzles 32, 33 by means of a pump 49 through hose connections (not shown).

The track 4 is designed for the marking of round or cylindrical workpieces, such as the coil shown in the drawings, and is therefore laid out in circular form, as shown, with the centre point of the coil 2 coincident with the centre of the arc formed by the track 4, so that the marking apparatus 5 can travel on the wheels 6 in a circular path about the coil.

WHAT WE CLAIM Is 1. An apparatus for marking a workpiece with a plurality of characters, the apparatus comprising a frame mounting a stencil member having a plurality of characters formed therein and a spray nozzle operable to spray marking material, first means for moving the stencil member relative to the spray nozzle for character selection, second means for moving the stencil member and the spray nozzle together with respect to the frame into a position for marking the workpiece at a particular location with a selected character, and third means for moving the frame relative to the workpiece for marking the workpiece with a selected character at a second location.

2. An apparatus as claimed in claim 1 in which the stencil member and spray nozzle are movable by the second means both vertically and laterally, on the frame.

3. An apparatus as claimed in claim 2 in which the stencil member and spray nozzle are carried on a support movable laterally on a table movable vertically.

4. An apparatus as claimed in claim 3 in which the second means comprises a first piston and cylinder unit located within the frame, the table being located on the piston of the first piston and cylinder unit, and a- second piston and cylinder unit carried by the table, the support being-connected to the piston of the second piston and cylinder unit.

5. An apparatus as claimed in claim 4 in which the second piston and cylinder unit is located in a cavity in the table covered by the support.

6. An apparatus as claimed in claim 2, 3, 4 or 5 in which the stencil member comprises an endless strip.

7. An apparatus as claimed in claim 6 as dependent on claim 3, 4 or 5 in which the support mounts shafts of guide rollers for the stencil member.

8. An apparatus as claimed in claim 7, in which each guide roller has teeth at its upper and lower periphery meshing with perforations provided in the stencil member.

9. An apparatus as claimed in claim 7 or 8 having three of the guide rollers located at respective corners of a triangle, the first means being arranged to drive one of the rollers.

10. An apparatus as claimed in claim. 9 in which the first means comprises an electric stepping motor with a hydraulic torque amplifier.

11. An apparatus as claimed in claim 9 or 10 having a colour spraying device including the spray nozzle positioned between the two guide rollers located to be nearer to the workpiece to be marked.

12. An apparatus as claimed in claim 11 in which the spraying device is pivotable about a substantially horizontal axis, a tank for containing cleaning liquid being located below the colour spraying device.

13. An apparatus as claimed in claim 11

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. operation can begin at the required time. For this purpose a piston and cylinder unit 37 is secured to the bearing pin 28 in a position above the spray nozzle 33, which is pivotally connected thereto, so that by pivoting about the axis 33a the spray nozzle 33 can have its aperture submerged in the tank 36'. Likewise the spray nozzle 32 is connected to a piston and cylinder unit 38, by means of which it can be lifted and lowered. The piston and cylinder unit 38 is arranged upon a pivot arm 39, which can be swung about the bearing pin 28 by means of a driving unit 40. After the raising of the spray nozzle 32 by means of the piston and cylinder unit 38 and swinging of the pivot arm 39 by means of the drive unit 40 located upon the arm 27, the spray nozzle 32 can be immersed in the tank 36. For the purpose of cleaning the characters 30a formed in the flange portion 30 of the angle section ring 29, there is provided at the underside of the arm 27 a cleaning brush 42 driven by means of a motor 41 to effect the cleaning operation from above the flange portion. Likewise, for the purpose of cleaning the characters machined in the cylindrical portion 31 of the angle section ring 29, a cleaning brush 44 is provided, which is supported upon the bearing pin 28 and piston 9 of the piston and cylinder unit 8. In a similar manner the horizontal sideways movement of the piston 14 of the piston and cylinder unit 13 is arrested through the action of a further end switch (not shown). This takes place when a further feeler 46, which is secured to an arm 47 carried upon the bearing pin 28, makes contact with the outermost turn of the coil 2. The colouring matter used for the marking operation, which is contained in a tank 48 carried upon the arm 27, is pumped to the spray nozzles 32, 33 by means of a pump 49 through hose connections (not shown). The track 4 is designed for the marking of round or cylindrical workpieces, such as the coil shown in the drawings, and is therefore laid out in circular form, as shown, with the centre point of the coil 2 coincident with the centre of the arc formed by the track 4, so that the marking apparatus 5 can travel on the wheels 6 in a circular path about the coil. WHAT WE CLAIM Is

1. An apparatus for marking a workpiece with a plurality of characters, the apparatus comprising a frame mounting a stencil member having a plurality of characters formed therein and a spray nozzle operable to spray marking material, first means for moving the stencil member relative to the spray nozzle for character selection, second means for moving the stencil member and the spray nozzle together with respect to the frame into a position for marking the workpiece at a particular location with a selected character, and third means for moving the frame relative to the workpiece for marking the workpiece with a selected character at a second location.

13. An apparatus as claimed in claim 11

or 12 having a tank for containing a cleaning liquid and associated with cleaning brushes located in each run of the stencil member between the said two guide rollers and the third roller.

14. An apparatus as claimed in any one of claims 2 to 13 having first and second feelers responsive to engagement of the workpiece thereby to stop the vertical and the lateral movement respectively of the stencil member and the spray nozzle toward the workpiece.

15. An apparatus as claimed in claim 1, 2, 3, 4 or 5 in which the stencil member comprises a ring having a cylindrical portion and a flange portion, each portion having characters formed therein.

16. An apparatus as claimed in claim 15 as dependent on claim 3, 4 or 5 in which the ring is journalled on a bearing pin carried by an arm extending from the support, the first means being arranged to rotate the ring.

17. An apparatus as claimed in claim 16 having the spray nozzle arranged substantially vertically above the flange portion of the ring upon the outer end of the arm, and a second, substantially horizontal, spray nozzle arranged upon the lower end of the bearing pin within the cylindrical portion of the ring.

18. An apparatus as claimed in claim 17 in which the spray nozzles are movably mounted, and piston and cylinder units are provided for dipping the spray nozzles into tanks for containing colour solvent medium.

19. An apparatus claimed in claim 16, 17 or 18 having at the underside of the arm a driven cleaning brush positioned above the flange portion of the ring, and a further driven cleaning brush carried upon the bearing pin within the cylindrical portion of the ring.

20. An apparatus as claimed in any of claims 16 to 19 having first and second feelers carried respectively on an extension of the arm and an extension of the bearing pin and responsive to engagement with the workpiece to stop the vertical and lateral movements respectively of the stencil member and the spray nozzle towards the workpiece.

21. An apparatus as claimed in any preceding claim for marking a generally cylindrical workpiece the frame being arranged to travel on wheels along an arcuate track centred on the centre point of the workpiece.

22. An apparatus as claimed in claim 21 in which the third means comprises an electric stepping motor with a hydraulic torque amplifier arranged to drive the frame wheels.

23. An apparatus for marking workpieces substantially as herein described with reference to figures 1 and 2 or figures 3 and 4 of the accompanying drawings.