Patent GB-1252820-A (GB)
IPC: B65G49/04
Filed: 1969-10-30
Abstract: 1,252,820. Conveying and orientating parcels. NATIONAL CASH REGISTER CO. 30 Oct., 1969 [31 Jan., 1969], No. 53120/69. Heading B8A. [Also in Division G1] Apparatus for handling a plurality of multisided items 42, each having an identifiable mark (not visible in the drawings) on one side only, comprises means 52, 60, 74, 90 for supplying the items successively in uniformly spaced relationship on to a conveying platform 108 which 1s continuously moving in operation, and a plurality of scanning means S1-S4 positioned adjacent the conveying platform 108 and arranged to search for the identifiable marks on the items 42 as they pass along the platform 108 and to provide a signal to processing circuitry (Figs. 15 and 16) upon detection of such a mark. A plurality of turning means T1-T7 are each selectively operative under the control of the processing circuitry to withdraw selected items from the platform 108, rotate a withdrawn item about a horizontal or vertical axis thereof, and replace the withdrawn item on the platform 108 at substantially the same position on the platform from which it was withdrawn. The arrangement is such that, in operation, each item is turned, if necessary, by the turning means so that finally the side containing the identifiable mark is in a predetermined spatial relationship, e.g. uppermost, with respect to the platform 108. The supply means 52-90 includes an input conveyer system 52-74 arranged to feed the items 42 to an assembly comprising a pair of horizontal discs 86, 88 having their upper surfaces coplanar and adjacent each other and having their vertical axes spaced apart transversely to the direction of feed of the items, the discs rotating in opposite directions and being separated by a narrow conveyer belt 92. The latter feeds the items on to a second narrow belt 90 on either side of which are shoots leading to reversely running belts 98, 100. Thus the items, e.g. parcels 42, which are not centred on the belt 92, are conveyed back by the belts 98, 100, and are fed again into the input system 52-90. The input conveyer 52 rises to discharge the parcels on a shoot 58 which in conjunction with control exercised by a photo-cell PCH and associated circuitry, controls the flow on to a a belt 60. Members 68, 70 deflect the parcels to the centre of belt 60. The latter feeds the parcels on to belt 74, associated with which is a deflector surface 80 carrying a deflector member 82. The latter tends to rotate parcels on to a more stable side.  The turning means T1-T7.-If in response to an output signal from the scanning means S1, the turning means T1 (Fig. 2), is brought into operation, a pusher unit 118 is energized. This comprises a rotatable arm 122 carrying pushers 124, 126. The latter turn as the arm 122 turns, so that the plane of each pusher remains parallel to the longitudinal axis of the belt 108. Thus one or other of the pushers 124, pushes the parcel 42 on to a conveyer belt 140. The latter is twisted through 90 degrees so as to turn the parcel this amount about a horizontal axis (in an anticlockwise direction as viewed looking downstream relative to the belt 108) and slide it back on to the conveyer 108. The turning means T2 is fed by a second pusher unit 118 in response to an output from the scanning means S2 and has the effect of turning a parcel, so deflected, about a vertical axis. This is effected by a conveyer belt section 144 which has its planar horizontal conveying surface disposed in a curve about a vertical axis. The parcel is fed from the belt 108 to the belt 144 by a conveyer 142 consisting of a series of side-by-side endless belts 148 and is discharged back on to the belt 108 by a similar conveyer 148. The parcel returns to the belt 108 at the same point of the belt at which it would have been if it had not been diverted by the pusher unit 118, and its orientation is changed by 90 degrees clockwise as viewed from above. The turning means T3 is fed in response to an output from the scanning means S3, and is similar to the means T 1 except for the fact that it is disposed on the other side of the belt and thus turns the parcels in a clockwise direction. Means T4 is identical to T1 and is also operated in response to the output from S3. Means T5 and T6 are identical to T2, and so is T7, except for the fact that it is disposed on the other side of the belt 108 and thus turns the parcel in an anticlockwise direction. When each parcel reaches the scanning means S4, it has been turned as necessary about longitudinal and/or vertical axes and the identifiable mark is now positioned in any one of four quadrants that surface of the parcel which is now upwardly facing. The parcel now has its upper face scanned by means S4 and output signals from the latter actuate as necessary turning means T5, T6 and T7 to turn the parcel about a vertical axis until the mark arrives in a given quadrant The means T5 and T6 are identical with T2 Means T7 is also identical with T2 except for being on the opposite side of the belt 108. The scanning means S1-S4.-The means S1 consists of a housing 110 disposed above the conveyer 108 and having light blocking curtains 114 (Fig. 6, not shown) through which parcels pass into the interior of the housing. The L.H. side (looking in the direction of conveyance) of each parcel is illuminated by two 15-inch-long lamps 280, (282) (Fig. 8, not shown). The top of each parcel is illuminated by four 30 inch-long lamps 294, (296), (298), and (300). A scanning unit 116 is mounted to scan the top and L.H. side of each parcel. It consists of a mirror assembly 342, 344, 346, 348, rotated at 3,600 r.p.m. by a synchronous motor 336. Thus light from the lamps 280, (282), 294, (296), (298), (300), reflected from the top and L.H. side of the parcel is reflected by the rotating mirrors 342, 344, 346, and 348, along a housing tube 324 so as to be refracted by triangular prisms 368, 370, thereby to be directed to photo-multiplier tubes 372, 374. S3 is identical with S1 and S2 is similar to S1 but is arranged to scan the R.H. side of each parcel. The scanning means S4 is identical to S1 except for the fact that the scanning unit 116 is mounted as shown in broken lines (Fig. 7) to scan the top only of the parcel. A photo-cell 402 (Fig. 7) provides an output which is used to determine the limits of length of the parcel in conjunction with a lengthdetermining circuit (398) (Fig. 16, not shown). Operation.-The identifiable mark consists of a postage stamp printed with a transparent overlay of zinc orthosilicate doped with manganese. This material when irradiated by the 2,537- Angstrom ultra-violet energy of the lamps, gives off green light, in a phosphorescent manner, in a band of 5,250 Angstroms for several milliseconds after the irradiation is removed. The lamps are shunted with a bi-directional triode semi-conductor switch so that at a point in the A.C. cycle of the mains'supply to the lamps, the latter are short-circuited. This switch is operated by pulses generated by a photo-cell 358 (Fig. 10) excited by a light 356 shining through an aperture in a timing disc 350 rotating with the mirror assembly 342-348. Thus the scanning member 116 picks up light emitted phosphorescently in addition to the light it picks up when the lamps are energized, and which operates in response to reflective and fluorescent energy. Photo-multiplier 372 operates in the phosphorescent mode when the lamps are extinguished, and in a reflective mode when they are energized. During the same time as the latter operation, the tube 374 is used in a fluorescent mode. Sensitivity control is accomplished by using a standard optical signal provided by a lamp 542 (Fig. 9). The output from the tube 372 resulting from the lamp 542, is applied to an automatic sensitivity control (552) (Fig. 16, not shown). If no mark is detected by S1 (provided the length of the parcel as determined by the circuit (398) is less than 36 inches), the diverter 118 of T1 is energized after the expiration of a time delay of a circuit (409) (Fig. 15, not shown). If the parcel is more than 36 inches long, it passes T1-T2 without diversion. The length determining circuit (398) is also operative subsequent to passage of the parcel through S2, the result being that any parcel having a length greater than 20 inches is not diverted to T2. By the time the parcel has' reached S4, it will have been turned as necessary in response to the output signals of S1, S2, and S3 as processed by the logic circuitry of Fig. 15 (not shown), so that the mark is on its top face. It is then scanned by S4, which with its associated logic circuitry (Fig. 16, not shown), which includes X and Y co-ordinate logic circuits and associated clock and counter circuits, is able to determine in which of four quadrants (UL), (UR), (LL), (LR), (Fig. 12, not shown), the mark lies. The parcel is then turned by T5, T6, or T7 in response to this information so that the parcel is finally positioned with the mark in the desired quadrant.