Patent GB-968418-A (GB)
Title: Method and apparatus for parting rolled material especially billets
Inventor: SIGAL EVERARD
IPC: B23D36/00
Filed: 1962-03-02
Abstract: 968,418. Making ingots; shearing. F. MOELLER, and K. NEUMANN, [trading as VERWALTUNGSGESELLSCHAFT MOELLER & NEUMANN o.H.G.]. March 2, 1962, No. 8160/62. Headings B3A and B3W. In a method of dividing rolled material into lengths, the total length at the final cross-section is calculated from the weight of the billet and the number of pieces cut is varied so that each is within a predetermined length tolerance. The apparatus comprises a weighing machine 25 (Fig. 1), a roll train 27, a photo-electric cell 29, a shear 28 and a computer shown schematically in Fig. 2. The weight G of the billet 26<SP>1</SP> is fed into section 32 of the computer and is divided by the product of the specific weight " 8 " of the material and the final cross-sectional area Q in order to obtain the total length Lo which will result. The values " 8 " and " Q " are manually pre-set on sections 35 and 36 of the computer. The length Lo is fed into section 37 of the computer where it is divided by a number p, selected by the control circuit 38, into pieces of length L. This length L is fed to section 40 of the computer where it is compared with the maximum and minimum permissible values Lmax and Lmin which have been pre-set at 41 and 42, and if the length L is outside these limits a signal is generated which alters the number p in computer section 38, until an acceptable value of L is obtained. This system requires that the tolerance range #L(=Lmax - Lmin) multiplied by the number of pieces p is at least equal to the length L min. The calculated length L is converted to a time T by dividing the length L by the outgoing speed v of the rolled rod. This speed is determined by a device 30 on the final roll and is fed to computer section 45. The cutting sequence is initiated by the leading end of the rod passing the photo-cell 29 and a variable time #T, which has been pre-set at computer section 50, is added to the time T before the first cut is made to allow for the distance between the photo-cell and the shear 28. Thereafter cuts are made at intervals T. Since the calculated length Lo will invariably differ from the actual length produced it is desirable that any residual portion should be of such a length that it is still suitable for further handling and this is achieved by adding to the calculated length Lo an amount ALo which is equal to, or less than, the difference between the minimum rod length Lmin and a residual length Rmin which is permissible for a final rod. Therefore in the above calculations it is not the length Lo but the sum Lo+ #Lo which is divided fictitiously into equal individual lengths. The greatest factor contributing to the difference between the actual and calculated lengths of rolled rod is the variation in finished crosssection and this is compensated for by placing a measuring device after the last roll stand and feeding to the computer the actual crosasectional dimensions instead of the nominal dimensions set on sections 35 and 36. The actual speed of the rolled rod may also be determined by measuring or by a photo-cell and this information supplied to the computer to modify the time interval T. In a modification a photo-cell 60 or trigger (Fig. 4, not shown) is placed behind the shears at a distance corresponding to the length to be cut. The shear is operated when the leading end of the rod reaches the photo-cell 60 so that the length cut is independent of the speed of the material.