GB1571893A

GB1571893A - Automatic processing apparatus

Info

Publication number: GB1571893A
Application number: GB5106276A
Authority: GB
Original assignee: HALL AUTOMATION Ltd
Current assignee: HALL AUTOMATION Ltd
Priority date: 1977-12-07
Filing date: 1977-12-07
Publication date: 1980-07-23

Description

(54) AUTOMATIC PROCESSING APPARATUS (71), We, HALL AUTOMATION LIMI TED, a British Company, of Wiggenhall Industrial Estate, Watford, Hertfordshire, 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 present invention relates to automatic processing apparatus for use in the manufacture of large objects, and more particularly to such apparatus which may be used for the spray coating of objects.

Such spray coating may either be for the purpose of applying a decorative or protective coating to the object or for carrying out a moulding process by spraying a moulding material, e.g. glass fibre into or onto a mould.

The present invention provides an apparatus for enabling a process to be carried out automatically by means of an automatic manipulating device controlled in accordance with a programme, said apparatus comprising a gantry structure including a movable portion supporting said automatic manipulating device and a control system for controlling said movable portion so as to enable said automatic manipulating device to move both vertically and along one horizontal axis relative to an object to be processed which is disposed below the gantry and wherein the power supply to the automatic manipulating device is independent of the power supply to the movable portion of the gantry.

Advantageously, the automatic manipulating device and said movable portion of said gantry together are capable of nine degrees of freedom of movement, and the object to be processed may be capable of a further degree of freedom of movement relative to said gantry.

Preferably, the automatic manipulating device is of the type comprising a workhead, for example a spray-head, which is so mounted as to have a number of said degrees of freedom of movement e.g. six.

Typically the workhead is attached to the end of an arm of the manipulating device by a wrist-like mounting which provides for motion relative to the arm about two mutually perpendicular axes, as well as for rotation about the end of the arm. The arm is extensible, and is so mounted as to be itself movable about two mutually perpendicular (e.g. horizontal and vertical) axes.

An independent driving means, comprising a servo-controlled actuator, is provided for each of the motions of the manipulating device. Transducers provide electrical signals indicative of the instantaneous position relative to a datum for each axis of motion, which signals serve as feedback signals for the respective servo-mechanisms. The workhead may thus be made to assume any desired position by means of control signals of suitable values fed to the inputs of the respective driving means.

Advantageously both the movements of the movable portion of the gantry and the various motions of the manipulating device are brought about by means of a hydraulic control system.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a front view of one embodiment of apparatus according to the invention; Figure 2 is a side view on the line II-II in Figure 1, and Figure 3 is a diagram of the hydraulic control system.

The automatic processing apparatus to be described is particularly intended for spraying glass fibre into or onto large moulds for the production of glass fibre mouldings of large objects, such as boat hulls, and super-structures, tanks, and other body forms.

Referring to Figures 1 and 2, the apparatus basically consists of an automatic manipulating device A, suspended from a gantry B. The gantry consists of two vertical columns 1, joined by an upper cross member 2. Each column is made up of two parallel spaced beams la, ib between which is arranged a trolley 3 having wheels 3a.

The two trolleys are carried at opposite ends of a cross beam 4, again composed of two parallel spaced beam members, whereby movement of the trolleys 3 up and down the columns 1 effects raising and lowering of the cross beam 4. This movement is effected by means of a hydraulic ram 17, driving chains 5 which pass over pulleys 6.

A further trolley 7 having wheels 7a is supported on rails on the cross beam 4 and driven by a hydraulic motor 21. Supported from the underside of the trolley 7 is a platform assembly 8 which supports an automatic manipulating device 9 including a spray head 10 for the spraying of glass fibre material. The platform assembly 8 is capable of rotation through 1800 with provision for an intermediate position at 90" and rotation is effected by a hydraulic motor and chain assembly.

The automatic manipulating device 9, may be constructed and arranged so as to operate generally as described in either or both of British Patents Nos. 1,393,349 and 1,418,710 but include the sprayhead 10 which in this case is so mounted as to have six degrees of freedom of movement. To this end, the sprayhead is attached to the end of an arm 9a by a wrist-like mounting 9b which provides for motion relative to the arm about two mutually perpendicular axes as well as for rotation about the end of the arm. The arm 9a is extensible, and is so mounted as to be itself movable about two mutually perpendicular (e.g. horizontal and vertical) axes. Thus, the arm is pivotally mounted on a unit 9c, which is rotatably mounted on a base 9d. By suitable combinations of these motions, the sprayhead 10 may be made to assume any position within a working volume whose boundaries are determined by the dimensions of the manipulating device and the range of movement available in each degree of freedom. The platform assembly 8 is itself rotatably suspended from the trolley 7 so that it can rotate through an arc of 1800.

An independent driving means, comprising a servo-controlled actuator, is provided for each of the motions of the spraying device. Transducers provide electrical sig- nals indicative of the instantaneous position relative to a datum for each axis of motion, which signals serve as feedback signals for the respective servo-mechanisms. The sprayhead may thus be made to assume any desired position by means of control signals of suitable values fed to the inputs of the respective driving means.

The apparatus is operated by means of a hydraulic drive and control system hereinafter to be described. Control of movement along the horizontal and vertical axes of the gantry is continuous and positional feedback is provided by means of potentiometers driven by gears engaging in toothed racks fixed to the structure of the gantry.

The positional information is processed by means of a control system for the apparatus contained in a console 23. Interlocks are provided to inhibit operation of the manipulating device during movements of the movable portion of the gantry.

Figure 3 shows the hydraulic drive and control system for the movable portion of the gantry. The hydraulic pressure is obtained from a hydraulic power supply unit 11 including an electric motor driving a swash plate pump supplying hydraulic fluid, via a filter 1 la, to a main manifold 12 which is located on one of the vertical columns of the gantry. This manifold supplies hydraulic fluid through a series of pipes to the drive means for the vertical and horizontal axes, as well as to rotate the manipulating device and to control the six degrees of movement of that device.

Movement of the cross beam 4 along a vertical axis is controlled by a "centre off" double solenoid valve 13 which supplies oil via a throttle valve 14 through a single line to a separator unit 15. This unit splits the flow into two equal parts, through two lock valves 16 to feed two linear rams 17. These rams supply the lifting power to the cross beam 4 via the trolleys 3.

The operation in this vertical axis is as follows. The solenoid valve 13 is opened in one direction to allow fluid flow into the rams 17 via the separator 15 and the lock valves 16. When current is removed from the solenoid valve 13 by the cross beam 4 reaching its desired position, the lock valves 16 will lock the fluid in the rams 17 at this selected position. To lower the cross beam, the solenoid valve 13 is energised in the other direction which supplies hydraulic pressure to the pilot ports of the lock valves 16, thus opening the locks and allowing the cross beam to lower under gravity. A flow controller (not shown) to control the downwards speed of the cross beam is located underneath the solenoid valve 13.

Movement of the trolley 7 to drive the platform assembly 8 in the horizontal direction is controlled bv a centre off double solenoid valve 20 via manifold block 18 fed from the main manifold 12. The valve 20 supplies oil to and from a hydraulic motor 21 which drives the wheels 7a of the trolley 7 along its supporting rails. The speed is controlled by a flow control valve (not shown) located underneath the solenoid valve 20. Both solenoid valve 20 and motor 21 are located on top of the horizontally moving trolley 7.

Rotation of the manipulating device and Ihe platform assembly 8 can be effected through 1800 to enable the sprayhead to face directly fore or aft of the gantry. This motion is controlled by a bistable solenoid valve 19 which supplies fluid to a hydraulic motor 22. This motor drives a captive chain which rotates a spindle on the trolley between fixed stops. Speed is again controlled by a flow control valve (not shown) located underneath the solenoid valve assembly.

In this embodiment the cross beam 4 may have a vertical traverse of 3 metres and the trolley 7 a horizontal traverse of 4 metres.

It is essential that the power supply to the automatic manipulating device 9 is independent of the power supply to the movable portion of the gantry. This is necessary for the "teaching" phase of the device, as the manipulating device is taught with no hydraulic power on. To this end, a simple on/ off solenoid valve assembly (25, 24 in Figure 3) is located on top of the trolley in the hydraulic pressure line to the automatic manipulating device. This valve is controlled from the console for the apparatus.

In general, before the automatic spraying device can perform a specified spraying operation automatically, suitable control signals must be prepared. This may be done by putting the device into a "teaching" or data acquisition mode in which the various driving means to the automatic manipulating device are disabled. An operator standing on the base 8a of the platform assembly 8 can then manoeuvre the sprayhead manually so as to perform the required task.

During this teaching phase, the varying outputs of the several transducers are recorded, e.g. on magnetic tape. For subsequent automatic operation, the recorded programme is played back and the various signals routed to the control inputs of the respective driving means, thus causing the sprayhead to reproduce the sequence of movements experienced in the teaching phase.

The transducers may provide analogue output signals, which may be recorded in the same form or may be converted to digital form before recording. In the latter case, the digital signals recovered on playback are reconverted to analogue form before being fed to the driving means.

The teaching operation is controlled by means of a control panel accessible to the operator standing on the platform assembly 8 during the teaching phase. This is carried out in the following manner.

The operator will stand on the base 8a of the platform and operate the controls so as to place himself in the correct position to commence the spraying programme.

If the spraying of glass fibre to form a boat hull is considered, a mould in which the hull is to be formed is positioned beneath the gantry and mounted so that is can be moved along a horizontal axis beneath the gantry normal to the cross beam 4. With the boat hull mould at one end of its travel, the operator will position himself with the platform assembly 8 within the mould and with the sprayhead 10 pointing towards and adjacent the bow. He will then spray the area within his reach.

When this is completed he will park the manipulating device arm 9a at a predetermined location and reposition the movable portion of the gantry and index the hull mould along its axis so as to bring within his reach the next area to be sprayed, e.g. a part of the hull side. He will continue in this manner along the hull side until he is close to the stern of the hull when he will rotate the platform assembly and thus himself and the manipulating device through 180 , to continue the process for the stern section. He will then index the hull as he proceeds to spray along the other hull side until he again returns to the bow. This process may be repeated several times if necessary to build up a hull of the desired thickness. It will be understood that besides manipulating the sprayhead 10, the operator can control the horizontal and vertical displacement of the spraying platform 8 by means of the trolleys 3 and 7 to bring any area of the mould within convenient reach.

Once the apparatus has been "taught" in this way further spraying operations can be carried out automatically with the programme produced during the teaching phase without the necessity for the operator being present on the platform 8a. In this way, the exposure of an operator to toxic or harmful atmospheres during a spraying operation is largely avoided. Such effects can be entirely eliminated if the teaching phase is carried out by merely going through the necessary movements without employing the spraying material.

Clearly other patterns of spraying programmes may be devised besides that described, depending upon the type of article being moulded or coated. Moreover, moulding or coating operations may be carried out on the external surface of a mould form, e.g. to produce a glass fibre superstructure for a boat.

The apparatus of the present invention may be employed for fibre glass spray moulding or the spray coating of any large objects. Similarly, the process is not restricted to spraying. Other operations can also be carried out such as compacting by means of a roller carried by the manipulating device in place of the sprayhead.

WHAT WE CLAIM IS: 1. An apparatus for enabling a process to be carried out automatically by means of an automatic manipulating device controlled in accordance with a programme, said apparatus comprising a gantry structure including a movable portion supporting said automatic manipulating device and a control system for controlling said movable portion so as to enable said automatic manipulating device to move both vertically and along one horizontal axis relative to an object to be processed which is disposed below the gantry and wherein the power supply to the automatic manipulating device is independent of the power supply to the movable portion of the gantry.

2. An apparatus as claimed in claim 1, in which the automatic manipulating device can be selectively operated in a "teaching" or data acquisition mode during which the varying outputs of transducers incorporated in said device are stored as data in a store whose output is employed as the programme for the subsequent automatic operation of the manipulating device.

3. An apparatus as claimed in claim 2, in which the data store also stores data for controlling the movements of the movable portion of the gantry.

4. An apparatus as claimed in claim 1, 2 or 3, in which interlock means are provided so as to prevent operation of the automatic manipulating device during movement of the movable portion of the gantry.

5. An apparatus as claimed in any preceding claim, in which said automatic manipulating device and said movable portion of said gantry together are capable of nine degrees of freedom of movement.

6. An apparatus as claimed in any of the preceding claims, in which the object to be processed is mounted on means such that the object can be traversed along a horizontal axis.

7. An apparatus as claimed in any preceding claim, in which the automatic manipulating device is suspended from the movable portion of said gantry such that it can rotate through a predetermined arc.

8. An apparatus as claimed in claim 5, 6 or 7, in which the automatic manipulating device is of the type comprising a workhead which is so mounted as to have a plurality of said degrees of freedom of movement.

9. An apparatus as claimed in claim 8, in which the workhead is a sprayhead.

10. An apparatus as claimed in claim 8 or 9, in which the workhead is attached to the end of an arm of the manipulating device by a wrist-like mounting which provides for motion relative to the arm about two mutually perpendicular axes, as well as for rotation about the end of the arm.

11. An apparatus as claimed in claim 10, in which the arm is extensible, and is so mounted as to be itself movable about two mutually perpendicular axes.

12. An apparatus as claimed in any of the preceding claims, in which the gantry comprises two spaced vertical columns and the movable portion of said gantry comprises a horizontal beam which extends between the two columns and has a trolley mounted at each end, each trolley being operable two move up and down a respective column, and a further trolley mounted on and operable to move along the horizontal beam, said automatic manipulating device being suspended from said further trolley.

13. An apparatus as claimed in any of the preceding claims, in which an independent driving means is provided to effect each of the motions of the manipulating device.

14. An apparatus as claimed in claim 13, in which the independent driving means is a servo-controlled actuator.

15. An apparatus as claimed in claim 14.

including transducers to provide electrical signals indicative of instantaneous position relative to a datum for each axis of motion, said signals serving as feedback signals for the respective servo-mechanisms, so that the workhead of the manipulating device can assume any desired position by means of control signals of suitable values fed to the inputs of the respective driving means.

16. An apparatus as claimed in any of the preceding claims, in which both the movements of the movable portion of the gantry and the various motions of the manipulating device are effected by means of a hydraulic control system.

17. Automatic processing apparatus substantially as hereinbefore described with reference to the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. be carried out such as compacting by means of a roller carried by the manipulating device in place of the sprayhead. WHAT WE CLAIM IS:

1. An apparatus for enabling a process to be carried out automatically by means of an automatic manipulating device controlled in accordance with a programme, said apparatus comprising a gantry structure including a movable portion supporting said automatic manipulating device and a control system for controlling said movable portion so as to enable said automatic manipulating device to move both vertically and along one horizontal axis relative to an object to be processed which is disposed below the gantry and wherein the power supply to the automatic manipulating device is independent of the power supply to the movable portion of the gantry.

9. An apparatus as claimed in claim 8, in which the workhead is a sprayhead.

15. An apparatus as claimed in claim 14.