Dynamic weighing apparatus

Claim 2

Dynamic weighing apparatus for articles of comparable weight and bulk, comprising weight transducer means having a pass-band adapted to the desired rate of measurement and a range of measurement adapted to the weight of the said articles, a weighing platform, in said weight transducer means, the dimension in the direction of advance of the articles of said platform being at least equal to the maximum dimension of the articles in the said direction, heandling means for causing the said articles to advance in translation on the said platform, separated from one another by a minimum distance, equal to the said dimension of the platform, integration means for integrating the signal derived linearly from the signal supplied by the said transducer means during the entire duration of the passage of the article on the saiD platform, means for generating a transit-time correction signal inversely proportional to the mean speed of the crossing of the platform by the said article, and means for dividing the integrated signal by the said correction signal for generating an elaborated measuring signal representing the static weight of the article.

Claim 3

A weight transducer comprising: a weighing platform, a vertical connecting rod integral with said platform, support means, two parallel rigid arms of equal length arranged horizontally one above the other and each having one end thereof hinged to said rod, respective connecting means connecting the other ends of said arms to said support means, deflection blade means forming at least one of said connecting means and at least part of the arm integral therewith, said blade means being fixed in said support means, a plurality of strain gauges arranged in said blade means and connected to form a Wheatstone bridge in such a manner that a measuring signal supplied by said bridge through the action of an article crossing the platform is substantially independent of any parasitic tensile, compressive or torsional stresses applied to the said blade means, the stiffness of the blade means being selected as a function of the maximum bending moment exerted on it by the said article, and a vibration damping means provided and designed such that the pass-band of the said transducer, with an article present on the platform, ensures the desired rate and accuracy of the measurements.

Claim 4

A weight transducer comprising: a weighing platform, a vertical connecting rod integral with said platform, support means, two parallel rigid arms of equal length arranged horizontally one above the other and each having one end thereof hinged to said rod, respective connecting means connecting the other ends of said arms to said support means, deflection blade means forming at least one of said connecting means and at least part of the arm integral therewith, said blade means being fixed in said support means, a plurality of strain gauges arranged in said blade means and connected to form a Wheatstone bridge in such a manner that a measuring signal supplied by said bridge through the action of an article crossing the platform is substantially independent of any parasitic tensile, compressive or torsional stresses applied to the said blade means, the stiffness of the blade means being selected as a function of the maximum bending moment exerted on it by the said article, and a vibration damping means provided and designed such that the pass-band of the said transducer, with an article present on the platform, ensures the desired rate and accuracy of the measurements.

Claim 5

A transducer as claimed in claim 2, more particularly intended for weighing articles of a weight greater than about 10 grams and less than about 10 kilograms, in which the deflection blade means is in the form of an isosceles trapezoid, the axis of symmetry of the said blade means coinciding with the axis of the arm of the transducer integral with it, the pair of strain gauges belonging to two opposite arms of the Wheatstone bridge being adhesively secured to the same face of the blade, symmetrically with respect to its axis, the two pairs of gauges facing one another on either side of the blade and being arranged in close proximity to the fixing line of the blade.

Claim 6

A transducer as claimed in claim 2, more particularly adapted for articles of a weight of less than about 10 grams and for very rapid rates of measurement, in which the deflection blade means is a silicon single crystal, on one of the faces of which at least 4 strain gauges have been diffused.

Claim 7

A transducer as claimed in claim 2, in which the weighing platform comprises, at least as constituent elements, means for guiding in translation and having a low coefficient of friction, adapted to the nature of the articles to be weighed, guiding means similar to the preceding means being provided in addition upstream and downstream of the said platform.

Claim 8

A transducer as claimed in claim 5, in which the articles to be weighed are inert, the weighing platform is formed of parallel bars arranged along the direction of advance of the articles.

Claim 9

A transducer as claimed in claim 5, in which the articles to be weighed being live animals, the weighing platform is a tube of closed section corresponding to the maximum section of the said animals.

Claim 10

Dynamic weighing apparatus as claimed in claim 1, in which the said handling means are provided for articles of the same nature received in disorder and comprising: at least two means of transport adapted to the nature of the said articles and arranged in sequence of one another, the rate of advance of the downstream means of transport being several times higher than the speed of the upstream means of transport, guide means associated at least with the upstream means of transport constituting a gradually narrowing passage, the minimum width of which is determined by a particular dimension of the articles to be caused to advance.

Claim 11

Dynamic weighing apparatus as claimed in claim 8, in which the articles to be weighed being inert, the transport means are belts and the guide means are obliquely fixed walls arranged opposite one another above the upstream belt.

Claim 12

Dynamic weighing apparatus as claimed in claim 8, in which the articles to be weighed being live fish or crustaceans, the means of transport are streams of water and the guide means are pipes of sections and lengths adapted to the homologous dimensions of the said fish or crustaceans, the inlet aperture of the upstream pipe being appreciably larger than that of the outlet.

Claim 13

Dynamic weighing apparatus as claimed in claim 1, in which: the weight transducer means comprises a strain gauge bridge supplied off a voltage source, the signal supplied by the said bridge being permanently applied to the input of a first integrator circuit of analogue type, a signal derived from the said current source is applied to the input of a second integrator, also of analogous type, during a transit-time interval for generating the said transit-time correction signal, the commencement and end of the said time interval being determined respectively by the instants of arrival of the article in front of a first presence detector arranged in close proximity to the platform entry, and in front of a second presence detector arranged after the platform exit at a distance from the said exit approximately equal to the average dimension of the articles in the direction of their advance, means are provided for applying at the end of the said time interval the said transit-time correction signal to the input of the first integrator circuit for discharging the latter at a rate of discharge proportional to the said correction signal, measuring means are provided which receive a triggering pulse at the nstant of application of the said correction signal to the input of the first integrator circuit, then in blocking a weight detection pulse generated by a comparator circuit at the instant at which it detects that the amplitude of the output signal of the said first integrator circuit returns to a predetermined inoperative level, the said measuring means being adapted to generate analogy and/or digital signals respective of the static weight of the articles.

Claim 14

A classification device for articles as a function of N weight categories, intended to be associated with a dynamic weighing device according to claim 11 and comprising: a number (N-1) of monostable circuits whose durations of operation, adjustable as a function of the upper threshold of the (N-1) categoreis of lower weight, increase as a function of their rank, the said monostable circuits being all triggered in parallel by the said triggering pulse, a number N of logical AND circuits all receiving in parallel at their input the weight detection pulse generated by the said comparator, the direct output signal of each monostable circuit being applied to the input of the logical AND circuit of the same rank as it, the reverse output signal of each monostable circuit being applied to the input of the logical AND circuit of immediately higher rank, the pulses appearing at the output of the said N logical AND circuits are weight classification pulses respectively characteristic of the said N weight catagories, more particularly adapted to be respectively applied in counting to N pulse counters for supplying the respective numbers of articles falling into each of the said N categories.

Claim 15

A device for sorting articles into four categories and intended to be associated with a dynamic weighing device according to claim 1 comprising downstream of the weighing platform: a means of transport adapted to the nature of the said articles advancing at a speed at least equal to and preferably appreciably higher than the exit speed of the articles from the said platform, a first switching device adapted for carrying an article along by the said means of transport towards a firSt or a second pair of discharge passages as a function of a binary sorting signal X, a second and third switching device arranged downstream of the first switching device at the heat respectively of the said two pairs of passages, the second and third switching devices being respectively adapted, as a function of binary sorting signals Y and Z, to cause an article to be carried along by the said means of transport towards the first and second discharge passages of each of the said pairs of passages.

Claim 16

A device for sorting articles according to claim 13, in which the said transport means is a belt when the article is inert, and a stream of water when the article is a live fish.

Claim 17

A control device for sorting articles into four weight categories intended to be associated with a classification device according to claim 12 and to generate the three binary signals X, Y and Z necessary for the operation of the sorting device, comprising three bistable circuits elaborating respectively the said signals X, Y and Z, the terminals for putting into the active state the bistable circuits supplying the signals X and Z and receiving respectively the weight classification pulses supplied by the logical AND circuits of rank 2 and 4, the terminals for putting into the active state the bistable circuit supplying the signal X and receiving the output pulses of a logical OR gate, to the input of which are applied the weight classification pulses supplied by the AND circuits of rank 3 and 4, the terminals for returning to the passive state the three bistable circuits receiving in parallel a pulse derived from the signal generated by the presence detector arranged at the exit of the transducer platform.

Claim 18

A device for totalling by category the weights of articles respectively classified in N categories, intended to be associated at one and the same time with a dynamic weighing device according to claim 11, supplying a digital output signal and with an article classification device according to, comprising N transfer elements rendered respectively operative by the N weight classification pulses operating in such a manner that the digital signal supplied by the said dynamic weighing device is returned to zero after having been transferred and counted in the totalling counter selected by a given weight classification pulse.