GB1561292A - Testing devices - Google Patents

Description

(54) IMPROVEMENTS RELATING TO TESTING DEVICES (71) We, WELLMAN MECHANICAL ENGINEERING LIMITED, of Willenhall Road, Darlaston, Wednesbury, West Midlands WSl0 8LG, a British 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: This invention concerns for testing elongate articles which are notionally of cylindrical shape, such as tubes and billets.

In certain manufacturing methods it is necessary to produce a cylindrical article and feed the same into equipment for carrying out further method steps. The presence of projections from the surface of the article, such as flash left by forging dies, may have a deleterious and serious effect on the equipment. Similarly, in the automatic feeding of billets to an extrusion press, an oversize billet may cause damage.

In other cases, the equipment may be sensitive to articles which are bent, i.e.

not perfectly straight, even though of true cross-section. The object of the invention is to provide apparatus for testing in all of these respects, and which is adjustable to cope with a range of different diameters.

In accordance with the invention, we provide testing apparatus comprising a set of radiation emitters distributed angularly about an axis and a set of radiation receivers distributed angularly about said axis, said sets being mounted for angular adjustment about said axis with respect to one another and means being provided for maintaining each receiver in radiationreceiving relation with a respective emitter during adjustment of the relative angular position of the two sets.

With this arrangement, the effect of adjusting the two sets relative to one another is to vary the size of an imaginary iris formed by the radiation beams, as explained hereinafter, and the iris may be used to gauge the diameter of an elongate generally cylindrical article and detect any significant departure from true cylindricity.

Conveniently light beams are employed, and the sets of light emitters may be arranged in a circuit so that in the event of any one beam extending between a light source and the corresponding cell being interrupted, an indication is given for example in the form of an alarm, or alternatively feed means which serve to displace the article through the testing apparatus may be stopped when a beam is interrupted.

The beam emitters and receivers may be mounted on complementary rods which extend between a pair of ring-like frames which are themselves concentric to said axis, the rods being pivoted at each end of the frames, and one of the frames is angularly adjustable so that when so adjusted all of the rods are taken from positions in which they lie on the surface of an imaginary cylinder (this being the extreme outer limit of adjustment) to positions in which they lie on the surfaces of a pair of imaginary frusto-cones located with their small ends adjacent one another, and which are also co-axial. A plane normal to the axis of the frusto-cones (which is also said axis) contains the imaginary iris, as explained hereinfater. In this movement the rods are taken from positions parallel to one another and each lying in a plane containing the said axis to inclined positions.This is due to one end of each rod remaining in position on the static frame, whilst the other end of each rod is turned with the moved frame in a rotational sense about the said axis. For this purpose the rods need to be telescopic, or have ends sliding in fulcrum blocks or the like, or alternatively the frames are arranged to move towards and away from each other in the rotational movement. It would be within the scope of the invention to turn both frames, e.g. in opposite directions, instead of having one frame fixed and one adjustable.

The feed means for moving articles through the apparatus may comprise waisted rollers having their axes transverse to the feed axis (i.e. the said axis) and spaced apart along the length of the same, and in - this event the spacing between the feed roller axes and the feed axis requires to be adjusted with the adjustable frame so that a truly cylindrical article resting on the feed rollers will have its axis coincident with the axis about which the beams are grouped if (but only if) the diameter of the article is the same as the diameter of the imaginary iris mentioned, and this may be done by mechanical means coupling both frames to move them bodily towards and away from a structure supporting the feed rollers when the one frame is angular adjusted.

The number of beams provided will depend upon the tolerances permissible in the articles concerned, and possibly also on the nature of the defect being tested.

For example if departure from straightness is the only relevant factor, then a small number of beams may be satisfactory since this might be detected even if only three beams were employed (depending possibly also on the length of the article and frequency of the support rollers). Similarly, if diameter beyond a particular tolerance was being tested, again a small number of beams would be satisfactory. Tf on the other hand, the presence of projections from the surface was in question, a larger number of beams might be necessary, to ensure that a projection beyond the predetermined tolerance did not pass through the apparatus between two adjacent beams.

However the inclination of the beams also assists in detection in such cases. The number of beams may also depend upon the actual dimensions of the articles in question.

The apparatus in accordance with the invention may be provided with means for securing the angularly movable frame in any predetermined position, which may be calibrated in terms of diameter, for simplicity in setting up for use with different diameter articles.

The invention will now be described by way of example with reference to the accompanying drawings, in which : - Figure 1 is a partly-sectioned front view of the apparatus according to the invention: Figure 2 is a side view in section; and Figure 3 is a plan view.

Referring firstly to Figures 1-3, the apparatus comprises a base 8 mounting a housing comprising, inter alia, the structural parts designated by reference numerals 10, 11, 12, 13 and 14. Within the space defined by the parts 10, 11, 13 and 14 there is mounted a frame 15 comprising front and rear plates 16 and 17 secured to and extending upwardly from a base plate 18 and two sets of crossbars 19 rigidly uniting the plates 16 and 17 together. The plates 16 and 17 are formed with coaxially aligned apertures 20 of substantially the same diameter, which diameter exceeds the largest bar or billet to be gauged by the apparatus. The frame 15 is mounted in slideways 21 provided on sidewalls 10 and 11 for vertical adjustment by means of an electric motor 22 and worm gear drive 23 so that the axis of apertures 20 can be made coaxial with the billet to be fed into the apparatus.In practice, the billet will be fed into the apparatus by waist rollers or the like. Whilst the axis of the billet will always lie in the same vertical plane, the horizontal disposition of its axis will be governed by its diameter, hence the need for vertical adjustability of the frame 15.

The extent of the vertical adjustment of the frame 15 is indicated by a pointer 5 pivoted to the part 12 and having one end coupled to the frame 15 by a pin and slot connection 6 and the other end overlying a graduated scale 7. In an alternative embodiment however, the necessary alignment between the billets and the apertures 20 could be achieved by vertical adjustment of the feed means, in which case the frame 15 would not need to be vertically adjustable.

An annulus 24 is rotatably mounted on the frame 15 and has a central opening which is concentric with and of substantially the same diameter as the apertures 20. An electric motor 25 and drive gear 26 is also mounted on the frame 15 and is arranged to rotate the annulus 24 via gear teeth provided around the outer periphery of the latter. The annulus 24 is also supported by gears 27 rotatably mounted on the frame 15. Thus, operation of the motor 25 is effective to turn the annulus 24 about the axis of apertures 20 and the billet and, more particularly, with respect to the front plate 16. A set of light-emitters 28 (twelve in all) are illustrated in Figure 1 but only two are shown in Figure 2) are mounted on the annulus 24 and are equi-angularly spaced about the annulus. Each light source 28 is mounted on a carrier 29 which, in turn, is pivoted to the annulus at 30 so that the carrier 29 can pivot about a radial axis. Associated with the front plate 16 there is a set of light-receivers 21 (i.e.

photocells) corresponding in number and distribution to the light sources 28. Each light-receiver 31 is mounted on a carrier 32 connected at 34 to the plate 16 for pivoting about a radial axis and each carrier 32 is linked with a corresponding carrier 29 by a slidable coupling rod 33 so that the beam of light produced by each emitter 28 always falls on a corresponding receiver 31 regardless of the relative angular positions of the annulus 24 and the plate 16.

When the annulus 24 is in an initial or zero setting with the rods 33 all parallel to the main axis of apertures 20, the light beams emitted by the light sources 28 will all lie on an imaginary cylinder whose diameter exceeds that of the apertures 20.

When the annulus is turned from this position however, the rods and hence the light beams are no longer parallel to the main axis, instead they are oblique and the effect of this is that, in a vertical plane perpendicular to the main axis and medial with respect to the sets of light sources and receivers, the light beams will pass through an imaginary circle concentric with the main axis and moreover at this position the light beams will be closer to the main axis than at other positions. Thus, the light beams, in effect, provide an " iris " whose diameter is governed by the angular setting of the annulus 24 with respect to the plate 16, and the iris can be used for gauging billets passed through the equipment.The extent to which the annulus 24 is turned may be indicated on a scale 40 by suitable means (not shown) and the scale may be graduated in terms of the "iris" diameter for given settings of the annulus. In use, if a billet is of a certain nominal diameter, then the frame 15 can be set to the appropriate vertical position to bring the main axis into coaxial relation with the billet axis and the annulus 24 can be positioned to form an " iris " of diameter slightly in excess of the nominal billet diameter so that, if there is any flash or projection on the billet, one or more of the light beams will be interrupted. Appropriate circuitry may be associated with the light receivers to detect when such interruption occurs and generate a warning signal, e.g. visual or audible.

WHAT WE CLAIM IS:- 1. Testing apparatus comprising a set of radiation emitters distributed angularly about an axis and a set of radiation receivers distributed angularly about said axis, said sets being mounted for angulr adjustment about said axis with respect to one another and means being provided for maintaining each receiver in radiationreceiving relation with a respective emitter during adjustment of the relative angular position of the two sets.

2. Apparatus as claimed in Claim 1 in which the two sets are mounted on respective axially spaced parts which are formed with aligned apertures through which an article can be passed.

3. Appartus as claimed in Claim 2 including means for feeding an article to be tested through said apertures and means for rendering the axis of the article and the axis about which said sets are distributed coaxial.

4. Apparatus as claimed in Claim 3 in which said parts are mounted on a frame and means are provided for effecting adjustment of the frame perpendicularly with respect to the direction of article feed by said feed means.

5. Apparatus as claimed in any one of Claims 1-4 in which detector means is provided for sensing interruption of the radiation beam passing between any one of the emitters and the respective receiver.

6. Apparatus as claimed in Claim 5 in which the detector means is operable to provide a warning signal in response to interruption of a radiation beam.

7. Apparatus as claimed in Claim 5 or 6 as appendant to Claim 3 or 4 in which the detector means is operable to produce a signal for arresting the feed means, or otherwise modifying operation of the same, in response to interruption of a radiation beam.

8. Apparatus as claimed in any one of Claims 1-7 in which each emitter is mounted on a pivotal carrier and each receiver is also mounted on a pivotal carrier, each carrier associated with the emitters being coupled to a respective carrier mounting a receiver in such a way that the radiation beam produced by the emitter remains incident on the respective receiver during relative angular adjustment between the parts.

9. Testing apparatus substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

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

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. connected at 34 to the plate 16 for pivoting about a radial axis and each carrier 32 is linked with a corresponding carrier 29 by a slidable coupling rod 33 so that the beam of light produced by each emitter 28 always falls on a corresponding receiver 31 regardless of the relative angular positions of the annulus 24 and the plate 16. When the annulus 24 is in an initial or zero setting with the rods 33 all parallel to the main axis of apertures 20, the light beams emitted by the light sources 28 will all lie on an imaginary cylinder whose diameter exceeds that of the apertures 20. When the annulus is turned from this position however, the rods and hence the light beams are no longer parallel to the main axis, instead they are oblique and the effect of this is that, in a vertical plane perpendicular to the main axis and medial with respect to the sets of light sources and receivers, the light beams will pass through an imaginary circle concentric with the main axis and moreover at this position the light beams will be closer to the main axis than at other positions. Thus, the light beams, in effect, provide an " iris " whose diameter is governed by the angular setting of the annulus 24 with respect to the plate 16, and the iris can be used for gauging billets passed through the equipment.The extent to which the annulus 24 is turned may be indicated on a scale 40 by suitable means (not shown) and the scale may be graduated in terms of the "iris" diameter for given settings of the annulus. In use, if a billet is of a certain nominal diameter, then the frame 15 can be set to the appropriate vertical position to bring the main axis into coaxial relation with the billet axis and the annulus 24 can be positioned to form an " iris " of diameter slightly in excess of the nominal billet diameter so that, if there is any flash or projection on the billet, one or more of the light beams will be interrupted. Appropriate circuitry may be associated with the light receivers to detect when such interruption occurs and generate a warning signal, e.g. visual or audible. WHAT WE CLAIM IS:-

1. Testing apparatus comprising a set of radiation emitters distributed angularly about an axis and a set of radiation receivers distributed angularly about said axis, said sets being mounted for angulr adjustment about said axis with respect to one another and means being provided for maintaining each receiver in radiationreceiving relation with a respective emitter during adjustment of the relative angular position of the two sets.

2. Apparatus as claimed in Claim 1 in which the two sets are mounted on respective axially spaced parts which are formed with aligned apertures through which an article can be passed.

3. Appartus as claimed in Claim 2 including means for feeding an article to be tested through said apertures and means for rendering the axis of the article and the axis about which said sets are distributed coaxial.

4. Apparatus as claimed in Claim 3 in which said parts are mounted on a frame and means are provided for effecting adjustment of the frame perpendicularly with respect to the direction of article feed by said feed means.

5. Apparatus as claimed in any one of Claims 1-4 in which detector means is provided for sensing interruption of the radiation beam passing between any one of the emitters and the respective receiver.

6. Apparatus as claimed in Claim 5 in which the detector means is operable to provide a warning signal in response to interruption of a radiation beam.

7. Apparatus as claimed in Claim 5 or 6 as appendant to Claim 3 or 4 in which the detector means is operable to produce a signal for arresting the feed means, or otherwise modifying operation of the same, in response to interruption of a radiation beam.

8. Apparatus as claimed in any one of Claims 1-7 in which each emitter is mounted on a pivotal carrier and each receiver is also mounted on a pivotal carrier, each carrier associated with the emitters being coupled to a respective carrier mounting a receiver in such a way that the radiation beam produced by the emitter remains incident on the respective receiver during relative angular adjustment between the parts.

9. Testing apparatus substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.