GB2100013A - Selectively weighing moving objects - Google Patents

Abstract

The apparatus comprises transport rollers (43) driven at the same peripheral speed as a weighing conveyor (31) and arranged therealong in such a way as to be individually shiftable from an operative position (43a- e,l,m) to an inoperative one (43 f-i), respectively overlying and underlying the weighing conveyor. The rollers (43) are sequentially controllable, to take and maintain the inoperative position, and then resume the operative one, whereby one single object (2a) at a time is deposited on the weighing conveyor, while being advanced therewith. <IMAGE>

Description

SPECIFICATION Apparatus for selectively carrying out checks on the weight of moving objects This invention relates to an apparatus for selectively carrying out checks on the weight of objects which are set into a flowing movement.

Preferably, such objects would be containers caused to proceed in a row at regular intervals from one another within an automatic packaging machine equipped with batching devices, and being preloaded by said batching devices with amounts of a product the weights whereof are required to lay close to a rated value within strict tolerance limits.

Occasionally, said batching devices are of a volumetric type and the product to be packaged, which is being delivered thereto, has progressively changing density, it being possible for the density deviations to occur over a significant range. With particular reference to such situations, it is current practice to employ packaging machines wherein it is provided for the density deviations in the product being delivered to the batching devices to be automatically detected at frequent intervals and the volume capacity of such batching devices to be adjusted accordingly. In this sense, packaging machines tend to effectively supply the containers with product in amounts by weight which fairly approximate the rated weight.

In any case, among the standards and regulations affecting this particular industry, increasing acceptance is achieving the notion of prescribing the ascertainment of the amounts of product actually introduced into the containers. It is contemplated that said ascertainment may be carried out with an indirect procedure and by sampling, that is by weighing individual and previously filled containers which, in the flow to the packaging machine, will be located at intervals to be decided upon. Through the same systematic ascertainment procedure, it would thus be possible to statistically check the packaging condition and, if necessary, to indicate those container batches which are to be discarded on account oftheirfalling out of the tolerance limits.

Actually, a checking procedure of an occasional nature is already carried out on the weight of the filled containers outside of the packaging path; such checks are often carried out, in fact, by assigning an operator the task of transferring a filled container to a platform type of weighing scale, which is located externally to said path and is in no particular way related to the packaging machine cycle.

On the other hand, continuous conveyor weighing scales are available, wherein the conveyor is a closed loop flexible configuration. Weighing scales of this type are manufactured in Western Germany by Optima Maschinenfabrik, Schwaebisch Hall, and in the United States by Hi-Speed Checkweighter Co.

Inc., Ithaca, N.Y. Thus conveyor in the above scales is arranged to receive and set into a flowing movement objects to be weighed, which are indeed weighed while moving. Thus, the conveyor generally comprises a section or length of a path wherealong the objects are arranged to move. In actual practice, the object to be weighed on continuous conveyor scales is often comprised of a layer of a material, which is deposited at a given moment onto the conveyor and a part of a continuous material flow. In this case, the scale would usually perform two weighings per full revolution of the continuous conveyor.Where instead individual objects being advanced in a row are to be weighed, such objects being placed at regular intervals from one another, then continuous conveyor scales impose heavy limitations on the output of the machine, such as a packaging machine, wherefrom the objects are delivered.

It is a primary object of this invention to make provisions for continuous conveyor scales, as placed along the flow path of objects rows, to incorporate an auxiliary apparatus, whereby individual objects in a row can be, over any desired period of time, subjected to weight checks by the weighing scale, without interrupting or otherwise slow down the object flow, the intervals separating objects thus being checked one after the other being selectable as desired within a wide range of values.

It is a further object of the invention to provide an apparatus as indicated, which is highly flexible in use as regards variations in the object flow, that is the size, speed of advance, and mutual distance of such objects.

These objects are achieved by the instant apparatus for selectively carrying out checks on the weight of moving objects, along the flowing path of a row of said objects, which apparatus is arranged to cooperate with a continuous conveyor weighing scale located at an area of said path, and is characterized in that transport rollers, driven at the same peripheral speed as the conveyor in said weighing scale, are arranged over said area alongside said conveyor, carried independently on said weighing scale, and individually shiftable from an operating position overlying said conveyor, whereat they are operative to receive said objects and set said objects into movement, to an inoperative position underlying said conveyor, whereat said objects are set into movement by said conveyor, as well as sequentially controllable to take and maintain the inoperative position thereof, and then resume the operative position thereof, thereby only one object at a time is deposited on the weighing scale conveyor and, while moving therealong, weighed, while below said one objects the set of rollers progressively occupying the inoperative positions thereof define a bin member which is only slightly larger than said one object and is advanced in conjunction therewith.

The invention details will be more clearly apparent from the following description of a preferred embodiment of the apparatus for selectively carrying out checks on the weight of moving objects, which apparatus is illustrated by way of example in the accompanying drawings, where: Figure lisa plan view, partly cut away, of this apparatus; Figure 2 is essentially a vertical longitudinal section view of the apparatus; Figure 3 shows a vertical cross-section of the apparatus; Figure 4 shows a further fragmentary vertical cross section; Figure 5shows a horizontal section through a control means for the cited transport rollers; Figures 6 and 7 are detail views of said control means for the transport rollers, being respectively elevational and front views;; Figures 8a and 8b are diagrams illustrating the mode of operation of the apparatus in substantially extreme operating situations, respectively; and Figure 9 is a wiring diagram of the control means for the transport rollers.

With reference to the drawing figures, objects, whose weight is selectively checked by means of the apparatus 1 according to the invention, are assumed to be box-like containers generally indicated at 2.

The containers may have sizes varying within a wide range; Figure 2 showing small size containers, indicated at 2a, whereas Figures 3 and 4 show iarge size containers indicated at 2b. The containers are delivered from an automatic packaging machine, not shown, which is equipped with batching devices, whereby a given amount of a product has been loaded into said containers. From the automatic machine, there emerge, continuously in a row, containers 2 which are all identical to one anotherand moved in the direction of the arrow A at regular or even distances from one another, the containers having their vertical wall in a common plane with the longitudinal alignment direction B.A conveyor belt 4 is arranged to receive the containers, the drive roller whereof, indicated at 5, is made rigid with a horizontal rotary shaft 6; the peripheral speed of the belt 4 is higher than that of the containers emerging from the automatic machine, so that the containers are spaced further apart from one another. A belt 7 overlies the belt 4, the drive roller whereof is indicated at 8 and is rigid with a rotary shaft 9. The lower run of the belt 3 is driven to move at the same speed as the upper run of the belt 4, and is effective to push on the head of the containers 2, thus ensuring that its flaps are sealed closed after they have been glued and folded down.The shaft 9 and the shafts of the other rollers wherewith the belt 7 engages are carried on a longitudinal stringer 10 which is guided siidably along coiumns 11 and is located and held at a desired level (in Figure 2, the stringer 10 is shown at its upper level). Thus, in accordance with the height of the containers 2, the distance or gap between the two adjacent runs of the belts 4 and 7 can be adjusted. The shafts 6 and 9 are driven off a vertical shaft 13 through respective bevel gear pairs 14a-14b and 15a-15b; to enable the stringer 10 to be raised and lowered, the shaft 13 is inserted slidably into a bevel gear 15b and box 16 which carries said gear rotatably, and is constantly held engaged tangentially by the gear 1 sub, which is provided with a key slidably movable in the groove 13a of the shaft.

The apparatus 1 is interposed between the delivery belt4 and a removal belt 17, the upper run whereof is aligned to and coplanar with that of the belt 4 and has the same speed as the latter. The belt 17 for removing the containers 2 is driven by a roller, not shown, which is connected to the powering system of the automatic machine; close to the apparatus 1, the belt 17 is driven by a roller 18 rigid with a rotary shaft 19. Between the roller 18 and shaft 13, whereby the motion is transmitted to the belts 4 and 7, a kinematic linkage is provided which ensures the same peripheral speed for the belts 17,4 and 7.With one end of the shaft 19, there is in fact rigid a sprocket wheel 20 for a chain 21 which, being redirected by the wheels 22 and 23, drives the wheel 24, made rigid with the rotary shaft 25; with that same shaft 25 there is made rigid a wheel 26a of a bevel gear pair, the other wheel 26b whereof is rigid with the vertical shaft 13; also rigid with the shaft 25 is a sprocket wheel for a chain 27, which drives a wheel 28 mounted, as explained hereinafter, on a shaft 29.

The apparatus 1 cooperates with a continuous conveyor scale 30 of the general type of those manufactured by the cited German and US companies. The continuous conveyor of the scale comprises a set of belts 31, which are passed around respective pulleys on a driven roller 32 and drive roller 33 made rigid with respective shafts 34 and 35.

The shafts 34 and 35 are carried rotatably between two longitudinal girders 36 which constitute the top of the scale moving mechanism. The shaft 35 is driven by a variable speed motor unit 38, which is adjusted to impart the same speed to the belts 31 as the peripheral speed of the belts 4 and 17; the body of the unit 38 is carried on one of the girders 36. The upper runs of the belts 31 constantly move in the direction A, and are supported by strips 39 located between the two girders 36 and are attached above projections 40 extending from said girders at regular intervals. The mechanism 37 is supported by a case 41, which constitutes the stationary portion of the scale 30 and is mounted above a platform 42.As will be explained hereinafter, the apparatus 1 coordinates the operation of the scale 30; in fact, it establishes which containers 2 the scale is to check for weight and determines each time the deposition of just one of said containers onto the scale and allows for the latter a period of operational freedom wherein the scale has plenty of time for performing the weighing.The weighing occurs by virtue of an electromechanical position tranducerwhich is builtin in the scale 30: the signals, suitably amplified, supplied by the transducer are proportionai to the deviation of the actual weight of a container being checked from a desired weight rating; the amplified signals are then suppiied to an electronic processor which processes them to provide a record and/or display of the weighings and, accordingly, an account of the same, as well as to effect corrective operations on the automatic machine batching devices.

It should be noted that the scale 30 is inherently capable of performing, even prior to the weighings, a check on the tare such as to eliminate those effects which would be exerted on the weighings by intervening weight deviations of the moving mechanism 37, as due for example to dust build-ups on that same mechanism or dust dropped therefrom.

The apparatus 1 comprises a plurality of transport rollers, which are shiftable, as will be explained hereinafter, from an operative position to an inoperative one and are generally indicated at 43; each of said shiftable rollers comprises a group of disks rigid with a respective horizontal shaft 44; in the particular embodiment shown, eleven such shiftable rollers are provided which are designated with the refer ence characters 43a, b, C, d, e, f, g, hi, /, m, in that order from the belt 4 to the belt 17. The various disks of the rollers 43 extend in longitudinal vertical planes intercalated with the vertical planes of the various belts 31; the shafts 44 of those same rollers are located above the girders 36 and between the projections 40 thereof, they being inserted between the lower and upper runs of the belts 31.In the particular embodiment shown, the shiftable rollers 43 are regularly distributed inside the area included between the two rollers 32 and 33 of the belts 31; anyhow, shiftable rollers may also be provided externally to said area and specifically between the roller 32 and roller 5 of the belt 4. In the illustrated embodiment, between the rollers 5 and 32, nonshiftable transport rollers are provided; these rollers are of the disk type 45, 46 and provided with respective shafts 47,48. Similar non-shiftable transport rollers 49,50 of the disk type, with the respective shafts 51,52, are provided between the rollers 33 and 18.The various shafts 44 and shafts 47,48, 51 and 52 are carried between two longitudinal box-like girders 53a and 53b, which are located externally of the girders 36 of the scale moving mechanism and are independent thereof; the girders 53a and 53b are attached to the tops of legs 54, which extend from the platform 42 upwards. The supports for the ends of the shafts 47,48,51 and 52 are secured to the box-like girders 53a-b; the supports for the ends of each shaft 44 are instead comprised of respective rocker arm elements 55a-b, which are respectively journaled at 56a-b to the girders 53a-b, along a common cross axis with those same girders. Each rocker arm 55a-b is loaded, against the rod 57a-b of a ram 58a-b, by a small spring-loaded piston, the pressure of the spring whereof can be calibrated through a screw device 59a-b.The rams 58a and 58b which actuate each shaft 44 are of the short stroke single-acting type; their simultaneous supply with pressurized air is accomplished through a normally open solenoid valve, generally indicated at 60; when the solenoid valve 60 is closed, the action of the spring-loaded pistons 59a-b causes the rams 58a-b to be exhausted through suitable valves 61 a-b communicated to the outside. When the rams 58a-b are under pressure, the tops of the disks of the related roller 43 overlie the upper run of the belts 31 of the scale, hence the roller 43 is shifted into the operative position thereof; when, by contrast, the rams 58a-b are being exhausted, the roller 43 is in its inoperative position, underlying the upper run of the belts 31.The rollers 43, in their operative positions, and the rollers 45, 46, 49 and 50 have their tops tangent to the common plane with the upper runs of the belts 4 and 17. The rollers 45,46,49 and 50, and the rollers 43, which receive their motion from the shaft 52, rotate in the same direction as the rollers 32 and 33 of the belts 31,and have the same peripheral speed as said belts, the rollers 43 turning both when in the operative position and inoperative position.A double chain 62 is in fact passed around the wheels 63 and 64, respectively rigid with the shafts 52 and 47; on the inside, the upper run of the chain 72 engages with the wheels 65 and 66, respectively rigid with the shafts 51 and 48; the wheels 67, rigid with the shafts 44 of the various rollers 43, engage from the inside either the upper run or lower run of the chain 62, depending on whether said rollers 43 are respectively in their operative or inoperative condition. The upper and lower runs of the chain 62 abut from the outside on related dual tracks 68, which are respectively configured by the top and bottom portions of the box-like girder 53b.With the shaft 52 is also rigid the gear wheel 69, which meshes with the wheel 70; this wheel meshes, in turn, with a wheel which, through a keyed connection, is at all times tangentially engaged with the shaft 19, at the remote end thereof from the wheel 20, while it can take various positions along that same shaft. In fact, the platform 42, whereon are mounted both the case 41 of the scale and the legs 54 supporting the girders 53a-b, which carry the rollers of the apparatus 1, is guided slidably across the bench 71 of the automatic packaging machine; the position of the platform 42 across the bench 71 is first adjusted and then retained by means of screw means 72.By adjusting the position of the platform 42, the longitudinal axis C-C, on the centerline of the set of belts 31 and plurality of rollers 43, is caused to align with the centerline of the path followed by the containers 2, which as mentioned, emerge from the belt 4 always with their wall 3 aligned with the direction B, and have different cross dimensions depending on their size.

Now, the solenoid valves 60 of the various rollers 43a...43m are controlled to close, as explained hereinafter, upon a suitable sector generally indicated at 73 facing respective proximity sensors 74a...74m. The sector 73 is removably attached to the end of said shaft 29 which is opposed to that carrying the wheel 28 mounted thereon; the sector 73 is located inside a cavity 75, to which access can be gained by removing a cover, now shown in the drawings. Thus, on the shaft 29 the sector 73 is each time secured which is particularly suitable to the size of the containers 2 being processed in the packaging machine: for example, to the containers 2a, there corresponds a sector 73a (Figure 2), and to containers 2b there corresponds a sector 73b (Figures 6 and 7). The sensors 74a...74m are arranged at the bottom of the cavity 75, and in the example shown, they occupy it over 180 ; in this same order, the sensors are regularly distributed angularly about the axis of the shaft 29, being alternately along two concentrical arcs to the same axis, one more to the outside and one more to the inside. On the bottom of the cavity 75, there is also arranged a further proximity sensor 76, which is located in particular more to the inside of said two arcs and at the bisecting line thereof and is adapted for the function which will be explained hereinafter. The sector 73 has one home or rest position which corresponds to that portion of the cavity 75 which is unoccupied by sensors.The sector 73 affects instead sequentially the sensors 74 and 76 as the shaft 29 receives its rotary motion from the sprocket wheel 28, which motion occurs in the direction of the arrow D. The wheel 28 (Figures 5 and 6) is in fact mounted on the shaft 29 by means of a free-wheel coupling 77, the engagement whereof is accomplished after the consent by a pawl device 78.

More specifically, and in a known manner, the coupling 77 comprises an outer sleeve 79, whereto the wheel 28 is attached, and an inner sleeve 80, which is keyed to the shaft 29; between the two sleeves, there intervene friction contact rollers 81, to the guiding cage whereof is secured a ring which forms peripherally the cam 82 with a tooth 82a and has on the front an arcuate groove 82b. In the groove 82b, there engages a pin 83 attached to a flange member 84, which is connected to the sleeve 80; between the cam 82 and flange 84, there intervenes a coil spring operating torque-wise and not shown in the drawings. The tooth 82a of the cam 82 is normally withheld by the pawl 85a, configured by one end of the lever 85 of the device 78; the lever 85 is in fact journaled at 86 and biased to engage with the cam 82 by the spring 87.When energized, an electromagnet 88 is adapted to act on the other end of the lever 85 in the sense of disengaging the pawl 85a from the tooth 82a (Figure 6) and of then enabling the engagement of the free-wheel coupling 77 and a rotation of the sector 73. As explained hereinafter, during the rotation of the sector 73, the scale 30 carries out a check on the weight of a container 2; prior to the sector 73 completing one revolution, the electromagnet 88 has been deenergized, thereby, upon completion of that same revolution, the tooth 82a is brought two re-engage the pawl 85a, the free-wheel coupling 77 is disengaged, and the sector 73 is stopped at the home position thereof, preparatory to a fresh rotation.It is contemplated that the electromagnet 88 can be energized in various ways, e.g. under control by a cam which follows, with a given ratio, the cycle of the packaging machine: thus, a relationship is established whereby checked for its weight is a container every so many processed containers during the respective packaging machine cycles. The energization may also be achieved under control by a timer; thus, one container is checked every so long a time period. The energization of the electromagnet occurs, at any rate, at a suitable phase, as will be explained hereinafter.Moreover, there exist a definite ratio between the angular velocity of the sector 73 and the peripheral speed, which is common for the belts 4 and 17, for the belts 31 and rollers 43 and which produces the advancing movement of the containers 2: that is, one container is to cover a distance equal to the distance between two successive rollers 43 within the same time lapse while the sector 73 covers the angle between two successive sensors 74.

It should be noted now that the diagrams of Figures 8a and 8b relate respectively to the sectors 73a, 73b and to the containers 2a, 2b; hereinafter, the lines of the diagrams will be designated with numerals carrying no suffix, which numerals appear instead in the figures with their respective suffix a, b when indicating magnitudes of different value. The line 89 is indicative of the distance between the rollers 43a and 43m, to which distance there correspond the 180 arc between the sensor 74a and sensor 74m. The line 90 is indicative of the distance between the rollers 32 and 33, and is placed in due relationship with the line 89.The lengths of the lines 91, their integer of fractional number and the gap separating them are representative respectively of the dimension of the containers 2 parallel to the axis C-C, of the number of the containers which simultaneously overlie the belts 31, and of the distance between the containers. The line 92, which is slightly longer than a line 91, is representative of the maximum number of rollers 43 intended to be simultaneously in their inoperative positions, and when expressed in degrees, corresponds to the angular span covered by the sector 73 to affect the related sensors 74.The line 94, being the difference between the line 90 and one line 91, is finally representative of that portion which, in the path of one container 2 from 32 to 33, is left available for carrying out the weighing by the scale; when expressed in degrees, the line 94 corresponds to the angular span covered by the inner annulus 95 of the sector 73 to affect the sensor 76.

With reference now to Figure 9, there are indicated at 60a...60m the coils of the various solenoid valves 60, which coils respectively relate to the rollers 43a...43m and, when energized, cause the closing of the respective solenoid valves and the lowering of the respective rollers 43 into the inoperative position. The various coils are located, in parallel to one another, between a pair of leads 96 and 97 forming the electric supply line: each coil 60a...60m is connected with one end directly to the lead 96 and with the other end is connectable to the lead 97 or in a most simple manner, that is solely through a related switch defined respectively by one of said proximity sensors 74a...74m, or in more complex way.That very simple manner concerns in all cases the coils 60g to 60m, the switches wherefor are the ones which are last affected by the sector 73: thus, as the sector moves sequentially to affect the switches 74g...74m and causes the closing thereof, there is at once caused the energization of the respective coils 60g...60m. The energization of the coils 60a to 60f can also be the immediate result of the closing of the respective switches 74a...74f: in this case, in accordance with the diagram of Figure 9, all the bridges 98a...98fshould be arranged "vertically", in which direction the figure only shows the bridges 98dto 98f, the arrangement achieving the direct connection of the movable contacts of the respective switches 74a...74fto the line lead 97. A second arrangement in which the bridges may be set, is the "horizontal" one, shown in the figure only for the bridges 98a...98c. When arranged horizontally, a bridge will connect the movable contact of the respective switch, no longer to the lead 97, but to the fixed contact of the following switch, that is of that switch which the sector 73 closes directly afterwards. A certain number of bridges is laid in the horizontal arrangement when a particular mode of operation is to be achieved, as will be explained hereinafter: the number of the bridges which are set horizontally will vary according to the size of the containers 2; the bridges are in all cases arranged horizontally, in their sequence, starting with bridge 98a.In the instance of containers 2a, only horizontally are set the bridges 98a...98c: thus, as the sector 73 produces the closing of the switches 74a...74c, there occurs no energization of the respective coils 60a...60c; in fact, owing to the interconnection established by the horizontal bridges 98a...98c between the switches, the energization of the coils 60a...60c is delayed and will occur concurrently with the energization of the coil 60d, upon the sector 73 also causing the closing of the switch 74d.

It should be noted that the de-energization is effected in the same manner for all the coils 60a...60m, that is as soon as the sector 73 ceases to affect the respective switches 74a...74m, regardless of the vertical or horizontal arrangement of the bridges.

The apparatus operation will be next summarized.

To selectively carry out checks on the weight of moving objects, with specific reference to Figure 2 and assuming first that all the bridges 98a...98f are arranged vertically and that in any case all of the switches 74a...74m are directly connected to the line lead 97. As the electromagnet is energized, the sector 73 begins one rotation and to affect the sensors 74a and then 74b, and results in the lowering of the rollers 43a and then 43b into the inoperative position; the container 2, which being enetrained in the direction A by the rollers 45 and 46 presents itself on the belts 31, begins to bear thereon, since the roller 43a has been lowered and the roller 43b is being lowered.As the rotation of the sector 73 is continued, more sensors 74 are affected and more rollers 43 are lowered in succession, thereby the container is caused to fully bear on the belts 31 and entrained by the latter; moreover, the sensor 76 begins to be affected through which sensor the scale 30 is enabled to carry out the weighing operation. In fact, upon a second container appearing above the belts 31, the sector 73 has ceased already to affect the sensor 74a, so that the roller 43a will already be back into the operative position and provide support and entrainment for the second container, which remains then always raised above the belts 31.From now onwards, the sector continues to affect fresh sensors 74 and cease affecting others, so that below the container which is being entrained by the belts 31 and weighed, there is formed a bin 99 of sort, which is slightly larger than the container and comprises the set of rollers 43, which remain temporarily in the inoperative position; then, the bin 99 will proceed gradually along with the container being weighed. In Figure 2, the third container from the right is being weighed, the sensors 74f...74i and 76 are being affected by the sector 73, and the rollers 43f...43iform for the time being the bin 99.As the container 2, which has been weighed, begins to leave the belts 31, the sensor 76 terminates the period during which it has been affected by the sector 73, the scale 30 having been allowed all the time required to perform the weighing and being only to return to its operative state at the next revolution of the sector 73; as the container moves out of the belts 31, also the last sensors 74 cease to be affected, thereby the last rollers 43 are moved back up and the bin 99 is progressively deleted: the bin will begin to reappear, form itself, and advance, starting with roller 43a, only upon the sector element 73, after completing its one revolution path, completing another revolution.

Thus, the apparatus disables the scale from weighing, it transporting the containers itself, above the scale conveyor, by means of rollers; in the event of bridges 98 being vertical, that same apparatus accomplishes instead the weighing of one container causing it to be transported instead by said conveyor from the very moment that the container appears at the conveyor inlet. In this sense, said rollers are lowered below the conveyor in a sequence whereby the number of the rollers simultaneously lowered increases progressively until it reaches a maximum when the whole container is resting on the conveyor; thus, said bin 99 will progressively appear, to then move onwards and be progressively deleted.

Where the bridges 98, in a required number, are arranged horizontal, the bin will appear instantaneously in its completed state; the bin will then move together with the container to be weighed, and as the latter is removed from the scale conveyor, the bin is deleted. In this case, the first rollers 43 receive the container to be weighed while they are still all in the raised position; after the entire container overlies the belts 31,they are sharply lowered to deposit it onto said belts and enable the weighing thereof.

The invention so conceived achieves its objects. It will be susceptible to many modifications and variations, without departing from the scope of the instant inventive concept.

In practicing the invention, the materials used, as well as the shapes and dimensions, may be any suitable onesforthe intended application.

Claims (8)

1. An apparatus for selectively carrying out checks on the weight of moving objects, along the flowing path of a row of said objects, which apparatus is arranged to cooperate with a continuous conveyor weighing scale located at an area of said path, and is characterized in that transport rollers, driven at the same peripheral speed as the conveyor in said weighing scale, are arranged over said area alongside said conveyor, carried independently on said weighing scale, and individually shiftable from an operating position overlying said conveyor, whereat they are operative to receive said objects and set said objects into movement, to an inoperative position underlying said conveyor, whereat said objects are set into movement by said conveyor, as well as sequentially controllable to take and maintain the inoperative position thereof, and then resume the operative position thereof, thereby only one object at a time is deposited on the weighing scale conveyor and, while moving therealong, weighed, while below said one object the set of rollers progressively occupying the inoperative posi tions thereof define a bin member which is only slightly largerthan said one object and is advanced in conjunction therewith.

2. An apparatus according to Claim 1, characterized in that each said transport roller is provided with a wheel driven by a continuous chain in common with the other rollers and is carried on a pair of rocker arms controlled by an actuator of the type comprising a short stroke ram, thereby, with said ram at a first stroke end, the roller is in the operative position and the wheel thereof is in engagement with the upper run of said chain and, with said ram at the second stroke end, the roller is in the inoperative position and the wheel there of is in engagement with the lower run of said chain.

3. An apparatus according to Claim 2, characterized in that to said actuators for said transport rollers there correspond respective sensors, adapted to be affected in succession and over a period of time and accordingly effective to drive the respective actuators to reach said second stroke end and stay there, and to said weighing scale there corresponds a further sensor adapted to be affected in combination with sets of the former sensors and over a respective period of time and thus adapted to enable said weighing scale to become operative.

4. An apparatus according to Claim 3, characterized in that said sensors acting on the transport roller actuators, are arranged along a first portion of a closed path wherealong a movable element is driven for carrying out one revolution, controllably and in phase with the objects in said row, said movable element having an extension effective to simultaneously affect a set of said sensors and which is normally inoperative along the second portion of said path, the movable element being adapted to complete the displacement from one sensor to the next during the time when one of said objects is displaced from one transport roller to the next and being effective to also affect said further sensor arranged in said first portion of said closed path.

5. An apparatus according to Claim 3, characterized in that said sensors are effective to drive the respective ones of said actuators instantaneously, as said movable element, in completing its revolution, affects in succession said sensors, and correspondingly, starting from the outset of each revolution of said movable element, said bin progressively appears, is moved onwards, and progressivelydis- appears.

6. An apparatus according to Claim 5, characterized in that the first of said sensors affected in succession by said movable element as the latter completes its revolution are interconnected together such that the driving of the respective actuators to reach said second stroke end is delayed until the time when said movable element begins to affect in said succession the remaining sensors, intended instead for driving the respective actuators immediately, and such that the reverse driving for reaching the first stroke end occurs instantaneously and in that, correspondingly, starting from the outset of each revolution of said movable element, said bin appears instantaneously and then moves onwards along with the object to be weighed, and finally progressively disappears.

7. An apparatus according to Claim 1, characterized in that said conveyor scale and said transport rollers are located between a delivery belt and removal belt for said objects, said belts being driven at the same peripheral speed as the scale conveyor and transport rollers and being powered by a common motor intended to transmit the motion to said movable element through a free-wheel coupling adapted to be engaged under control and in phase, the scale conveyor being powered by a motor of its own.

8. An apparatus for selectively carrying out checks on the weight of moving objects, constructed and arranged for use and operation substantially as described herein with reference to the accompanying drawings.