Patent GB-591000-A (GB)
Title: Sequence timer and measuring control
IPC: B65H45/101
Filed: 1944-08-04
Abstract: 591,000. Folding fabrics. PRESTON, J. E. Aug. 9, 1944, No. 14953. [Class 42 (ii)] [Also in Group, XL] In apparatus for folding articles at a point dividing their lengths in a given ratio, the article passes over two trips and when both trips are actuated a relay means is continuously adjusted at one rate and when one of the trips is released the relay means is adjusted at a faster rate the folding operation taking place when the overall change in the relay means reaches a predetermined amount. Valves A, B, Fig. 1, fed with A. C. from transformer T are normally rendered non-conducting by bias applied from the upper end of potentiometer 37, through the respective trip contacts 1, 2. Condenser 39 is charged negatively from potentiometer 37 through the non-operated relay contact 40 and the grid rectifier action of valve C which is thereby rendered non-conducting. The leading edge of the article on reaching trip 1 disconnects the bias from valve A which conducts and its anode relay 18 operates and locks over contact 61. The leading edge on reaching trip 2 causes valve B to conduct and relay 17 operates to commence the discharge of condenser 39 through resistors 57, 58 in series. When the trailing edge passes over trip 1 valve A is biassed off and relay 18 releases to short circuit resistance 58 thereby accelerating the discharge of condenser 39, at the end of which valve C conducts and relay 50 operates, energizing solenoid 15 which actuates the folding blade 14. When the trailing edge passes trip 2 relay 17 releases and condenser 39 is recharged. Once relay 18 is released to produce the rapid discharge, it will remain released until trip 1 is operated at the same time as trip 2 is released, thus permitting articles to follow one another in close succession. If it is required to fold articles at the mid-point the maximum length for an article is twice the distance from trip 1 to blade 14. The minimum length is the distance between trips 1 and 2. Thus the discharge for a maximum length article is wholly at the slow rate and for a minimum length article wholly at the rapid rate, intermediate length articles having appropriate durations of slow and fast rates successively. The charging voltage for the condenser, Fig. 2, (not shown) may be varied according to the speed of the belt carrying the articles. In Fig. 3 (not shown), two blades, operated by two valves controlled by two condensers discharged by appropriate resistance combinations produce half and quarter folds. Folding may also be effected using one trip only, Fig. 10 (not shown). Two condensers in parallel, Fig. 11 (not shown), can be arranged to be discharged through a single resistance during the " slow rate " period, one being disconnected at the commencement of the "rapid rate" period. In Fig. 12 (not shown) at the end of the " slow rate period a condenser is temporarily connected in parallel with the usual condenser to take away half of its charge so reducing the subsequent discharge period. In an electro-mechanical arrangement, Figs. 4....7 (not shown) the timing device consists of an arm or " traveller adapted to be rotated by a slow speed wheel when both trips are actuated and by a high speed wheel when one of the trips is subsequently released. The "traveller" after moving through a predetermined angular distance operates a switch to energize the folding solenoid.