Patent GB-1340239-A (GB)
Title: Weight controlled slicing apparatus including gross error detecting means
IPC: B26D7/30
Filed: 1971-11-18
Abstract: 1340239 Food slicers PETER ECKRICH & SONS Inc 18 Nov 1971 [14 Dec 1970]53591/71 Heading A4C [ Also in Divisions B8 and G3] A food slicer which produces a stack of slices on a slice-receiving means has a take-away conveyer to remove the stack when it contains a predetermined number of slices, and means for continuously monitoring the weight of the stack such that should the weight of an incomplete stack deviate by more than a given amount from the standard weight for that size stack the take-away conveyer will act prematurely to remove the stack from the receiving means. If the error in the partial stack weight is within the prescribed limits the slice thickness is adjusted so that the completed stack has a predetermined total weight. SLICE CUTTING AND STACK REMOVAL. Food-stuff such as meat loaf is fed into a cutting area 10, Fig. 1, by feeding means 24, where successive slices are cut by knife 12. The slices are stacked on a platform 68, which is progressively lowered by a platform position control 78 as the stack is cut. The desired number of slices in a stack is preset onthe number of slices selector 116, Fig. 2, and each timea slice is cut the slice counter 116 is stopped by a signal emitted by the count pulse generator 118. When the desired number of slices has been cut a last slice signal is emitted by the slice counter 116 which operates, via AND gate 140 and OR gate 138 a take-away control 92. The take-away control 92 operates a take-away conveyer 80 which comprises a plurality of belts 86 pivoted about shaft 90 such that they can be raised between the lines 70 of the platform 68 to remove a stack of slices therefrom. SLICE THICKNESS CONTROL. A weigh cell 72 attached to platform 68 continuously monitors the weight of the stack, and provides an output voltage indicative of the stack weight. The slice counter and number of slices selector 116 provide a command weight voltage signal, the magnitude of which corresponds to the calculated weight of the number of slices cut in the stack, and of opposite polarity to the output signal of the weigh cell. The command weight signal and the actual weight signal are added at summing junction 124 to produce an error signal the magnitude of which indicates the amount by which the actual weight of the stack deviates from the weight corresponding to a correct weight completed stack. The polarity of the error signal indicates whether the stack is too heavy or too light. The error signal actuates the knife position control 20 and the feed rate control 52 so as to increase the slice thickness if the partial stack is underweight, or decrease the thickness if overweight. Movement of the knife 12 by the knife position control 20 affects the thickness of the next slice cut to correct the partial stack weight, while the change in feed rate affects the thickness of successive slices. STACK REJECT CONTROL. The error signal is also fed into differential amplifiers 128 and 130. The maximum acceptable partial stack weight errors are set on controls 132 and 134; if the error in stack weight exceeds the acceptable maximum either amplifier 128 or amplifier 130 will emit a signal which is fed into OR gates 136 and 138. The output signal of the OR gate 138 causes premature actuation of the take-away control 92 and the output of OR gate 136 causes reject control 112 to operate a flap 106 which diverts the rejected stack into a reject shoot 114. Alternatively the reject control 112 may be activated by a signal from a second weigh cell associated with the conveyer system. The output of the OR gate 136 also stops a decade counter 148 which emits a warning signal and switches off the slicer if more than a predetermined number of rejects occur in succession. The decade counter is reset by the last slice signal emitted by the slice counter when a full stack is cut.