GB2110393A

GB2110393A - Conveying apparatus

Info

Publication number: GB2110393A
Application number: GB08231241A
Authority: GB
Inventors: John Briggs Holt
Original assignee: National Research Development Corp UK
Current assignee: National Research Development Corp UK
Priority date: 1981-11-13
Filing date: 1982-11-02
Publication date: 1983-06-15
Also published as: NL8204406A; FR2516486A1; FR2516486B1; GB2109566A; NL191576C; GB2110393B; NL191576B

Abstract

A conveying apparatus comprises a plurality of compartments 1 each adapted to support an object to be weighed and means for conveying the compartments past a weighing location at which each compartment will rest on the platform 17 of a weighing means to register the weight of the compartment and its contents. Each compartment is coupled to the conveying means by a linkage 5, 5' having two pivot axes 7, 4' lying in one substantially horizontal plane and connecting the linkage respectively to the compartment and to the conveyor. <IMAGE>

Description

1

SPECIFICATION Improvements in and relating to conveying apparatus

The present invention relates to conveying 5apparatus and is concerned in particular, but not exclusively, with apparatus for conveying fruit such as apples and for presenting such fruit to be weighed.

In known fruit grading apparatus, a conveying means may use discrete compartments in a number of side by side lanes to convey items such as apples, onions and bulbs, from an input feeder over a succession of weighing units. In such an apparatus, each compartment is commonly linked to the conveying means by a pivot at one end of the compartment. At another point on the compartment, a peg extends and supports part of the weight of the compartment and its contents on the conveying means or on a stationary rail.

When the compartment reaches the weighing location, the peg is arranged to rest on a weighing means to register some part of the weight of the compartment and its contents as the compartment moves about its pivot. If the force applied by the peg to a peg-engaging element of the weighing means is above a set value, the element is deflected and the compartment is able to swing downwards so as to release its contents.

With such an apparatus inaccurate weighing may occur due to the variable position of the centre of 95 gravity of the item being weighed in relation to the axis on which the compartment pivots and to the peg which acts on the weighing mechanism.

UK Patent Specification 1549785 (NIRDC) describes an alternative design of conveying apparatus in which the individual compartments of a series of fruit-carrying compartments are connected by links to conveyor cross-rods positioned one pitch ahead of the compartments concerned. The links, which are pivotally connected to the cross-rods, may be connected to the compartments either rigidly or pivotally. In the first mentioned case, having the compartments pivot about a relatively long radius has the effect of reducing the influence of change of position of 110 the fruit in the compartment on the load sensed at the weighing location. In the second mentioned case, provided the compartment is so supported on the weighing means as to be stable during the weighing operation, the position of the centre of 115 gravity of the fruit within the compartment has no influence on the weight sensed. Thus in both cases, the disadvantages of the earlier apparatus are largely overcome.

An object of the present invention is to provide 120 a conveying apparatus enabling the improved accuracy of the previously patented apparatus to be achieved in a more compact manner than hitherto.

According to the present invention, there is provided a conveying apparatus comprising a plurality of compartments each adapted to support an object or substance to be weighed and conveying means for conveying the compartments GB 2 110 393 A 1 past a weighing location at which the compartments may be at least in part supported on a weighing means, the conveying means including a series of cross-members with each compartment coupled to the cross-member adjacent e.g. leading or following, that compartment by a respective linkage and each linkage being pivotally connected to the conveyor and to the associated compartment by pivotal connections having their pivot axes lying in a common plane which at least during weighing lies at not more than ten degrees or so to the horizontal.

If desired, the two pivot axes associated with each linkage could be arranged so as to be spaced apart across the width of the conveying means (with the axes aligned with the direction of movement of the compartments past the weighing location). However, in currently preferred embodiments of the invention, the pivot axes are instead spaced apart in the direction of movement of the compartments past the weighing location.

Conveniently, where the cross-member leads or follows the compartment to which it is coupled, then the cross-member lies at or close to the adjacent end of the compartment.

Conveniently, the pivot centre to centre length of the linkage Will approach the pitch spacing of the cross-members. Alternatively, it may lie between about 1/8 and 7/8 of the pitch spacing.

Conveniently, the, or some of the, links in the linkage house one or more buttons or the like which may be displaced by manual or other means to carry information relating to the contents of the associated compartment or of a compartment having a fixed relationship to that compartment.

Conveniently, the compartments are adapted to be partially supported by catch means acting on or carried by the conveying means or by components carried by the conveying means or moving at a fixed relationship with the conveying means.

Alternatively, each compartment may be supported by a peg or other member protruding sideways of the compartment and arranged to slide or roll along a fixed surface, so supporting the compartment, except where it is desired to weigh or discharge the contents of the compartment.

In a further alternative, each compartment is supported by a catch or other member mounted on or acting on another component located alongside the compartment and carried by the conveying means.

Conveniently, the apparatus also includes the weighing means for registering the weight of a compartment and its contents, the arrangement being such that during weighing the centre of gravity of the compartment and its contents is substantially directly above the effective weight sensitive area of the weighing means.

Conveniently, the apparatus also includes means for rotating objects in the compartments to facilitate a comprehensive assessment of other characteristics of the objects at one or more additional locations in the apparatus.

The invention also includes a fruit-grading 2 GB 2 110 393 A 2 installation including conveying apparatus according to the present invention.

In most if not all practical embodiments of the invention, the conveying means will comprise an endless conveyor with the loaded compartments carried on the upper run of the conveyor. Unless otherwise stated, the following description should be taken as referring to this active part of the conveyor run.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 shows a plan view of a conveyor compartment on the upper run of the conveyor, i.e. the working run; Figures 2, 3, 4 and 5 show side elevations of a compartment in various attitudes; Figure 6 shows a compartment without its conveyor-connecting links in positions; Figures 7 and 8 show side and plan views of a compartment with modified linkage; Figure 9 shows a side view of another modification; and Figures 10 and 11 show side views, at two different stages of its operation, of a further 90 modification.

In all cases, the conveyor is assumed to be travelling in the direction of arrowA in the drawings.

Thus referring now to Figures 1 to 6 of the drawings, the upper face of the compartment 1 has a depressed central part 2 designed to locate the apple or other item being conveyed. It may, as shown, have apertures 3 and 3' formed in it to permit means (not shown) positioned below the conveyor to cause the object being conveyed to be rotated while it is examined for quality or other characteristics. Suitable means for this purpose comprise a pair of endless belts positioned parallel with the length of conveyor below a line of 105 compartments so that part of an apple, for example, protruding through the apertures 3 and 3' contacts the belts. The belts may be driven at a different speed and, if required, in a different direction from that of the conveyor to cause the fruit to be rotated within the compartment.

If desired the drive to one or both of the belts may be intermittent or of variable speed so as to vary the speed or axis of the fruit rotation.

The compartment is generally positioned 115 between two conveyor cross-rods 4 and 4' which are connected to two or more chains or belts (not shown) which form part of the conveyor.

The compartment is located longitudinally relative to the cross-rods by the side links 5 and 5' 120 which may advantageously be connected together by a cross-member shown dotted at 6.

Alternatively the side links and cross connection may be formed from one continuous length of wire wrapped at least partially round the cross rod 4'.

The links 5 and 5' are arranged to pivot freely on the cross-rod 4' and by means of the pins or pivots 7 and 7' at their connection with the conveyor compartment.

A lip 8 or other protruding part of the leading 130 edge of the compartment is able to support the front of the compartment on the rod 4' and one trailing corner is generally supported by the catch 9 being hooked over the rod 4. This catch is pivotally connected at 10 to the compartment and is normally held in the attitude shown in Figure 6 by the hidden spring 11. If desired the catch 9 may be positioned on or close to the centre line of the compartment to reduce any tendency for twisting, or a second similar catch may be positioned at the other rear corner of the compartment. If desired these two catches may be linked together.

Alternatively one or more catches could be pivotally connected to the links 5 and/or 5' at a similar axis. In this case the springs 11 could be connected between the links and the one or more catches.

During the passage of the compartment over the weighing means the compartment is supported by the surfaces 12 and 12' forming part of the underside of the compartment. In this position the compartment is raised slightly by the platform 17 of the weighing means as shown in Figure 3 so that the lip 8 and the catch 9 are no longer in contact with the cross-rods. Since the pivots 7 and 7' and the rod 4' are in the same substantially horizontal plane and the vertical component of the mass of the links 5 and 5' is constant, accurate weighing may be achieved. A suitable known design of weighing means for this purpose is a spring supported platform with an inductive displacement transducer connected between the platform and the base to give an electrical output related to the mass being supported. Damping means are usually included.

Protuberance 13 and the upper surface 14 of the catch-carrying lugs adequately constrain the inverted compartment relative to the rods 4 and 4' when it is on the return run of the conveyor.

When it is desired to discharge the contents of the compartment, other than at the end of the conveyor run, the striker 15 is positioned to contact the arm 16 of the catch 9 as shown in Figure 4.

This causes the catch to pivot against the pull of spring 11 so permitting the compartment to pivot as shown in Figure 5 to discharge its contents. The forces on the catch are such that the compartment pivots downwardly to the extent that when the catch returns to its normal position in relation to the compartment it no longer engages with the cross-rod 4. A pin, ramp or wheel (not shown) positioned below the conveyor may be used to raise the compartment so that the catch 9 relatches over the cross-rod 4.

The striker 15 will normally be one of a number along the length of the discharge section of the machine and will be moved into its operative position by a solenoid or other power means when it is desired to discharge an item at the particular position.

An alternative embodiment is shown in Figure 9 where the same reference numerals as before have been used to indicate similar parts of k i 3 GB 2 110 393 A 3 the compartment. The only difference between this latter embodiment and those described earlier is that the side links 5, 5' now only extend about half way along the length of the compartment. The operation of this embodiment is the same as described above for the previous embodiment, a spring (not visible in Figure 9) being included as before to hold the catch 9 in the illustrated attitude until it is displaced by the striker 15 (see Figure 4).

In a further alternative (not shown), the catch arrangement described above is replaced by a peg or other member protruding sideways from a point located towards the rear of one of the side links 5 or the compartment 1 and arranged to slide along a fixed rail, so supporting the compartment, except where it is desired to weigh or discharge the contents. A small rotating member may be provided to avoid the wear associated with sliding.

In another alternative (not shown) the compartment may be supported if desired by a catch or other member mounted on or acting on another component located alongside the compartment and carried by the conveyor, generally as was described in UK Patent Specification 1549785 (NRDC).

UK Patent Specification 1548301 (NRDC) describes a fruit-grading apparatus in which push buttons in a carrying block are used to form a mechanical escort memory for carrying information relating to the quality or some other characteristic of the fruit being conveyed to the weighing position or being conveyed to and/or discharged at the required delivery point for the contents of a compartment. If desired, the same sort of mechanical escort memory may be combined with one of the side links of apparatus according to the present invention as shown by way of example in Figures 7 and 8 where reference numeral 18 indicates the combined side link and push button block and reference numerals 19 and 20 indicate the push buttons. These latter may be set manually to indicate an operator's decision on quality, for example, or may be set by electrical or mechanical means.

Figures 10 and 11 show a further embodiment which differs from those so far described in having the compartment pivoted to the following cross rod 4' instead of the leading cross-rod 4.

The various parts of the embodiment are similar or identical to those described above and the 115 same reference numerals have been used to indicate like parts throughout. The position of pins 7, 7' is again optional to allow longer or shorter links 5, 51 to be used if desired.

Apart from having the compartment swing about cross-rod 4' (to the position shown in Figure 11), the only significant difference from the earlier embodiments is that the repositioned catch 9 has the striker arm 16 projecting above the compartment, rather than below it, for engagement with an appropriately repositioned striker 15.

With reference to the catch 9, it should be noted that in the situation shown in Figure 10, the attachment point of spring 11 to catch 9 lies slightly below the imaginary straight line joining pivot 10 with the upper attachment point of spring 11 so that the action of the spring is to bias the catch 9 upwardly towards the position shown in Figure 10.

After disengagement, the cross-rod will be automatically returned to the retention slot in catch 9 as it engages and then runs along the sloping surface of the catch at commencement of the return journey of the compartment in the opposite direction to direction A in Figure 10.

It will be understood that the apparatus above described will generally comprise a plurality of lanes each containing many conveyor compartments.

Although the illustrated embodiments of the invention are primarily intended for use with apples, other objects, e.g. onions, bulbs etc., may be conveyed instead if desired with appropriate redimensioning and/or reshaping of the illustrated compartments if necessary.

As above indicated in the broadest definition of the present invention, conveying apparatus in accordance with the invention may also be used for conveying substances rather than objects. Embodiments for this purpose may, for example, be virtually idehtical to the illustrated embodiments except that the compartments will now be imperforate to prevent escape of the substance during the conveying and weighing stages. Conveniently, however, the trailing edges of the compartments will also have some sort of pouring lip to assist the controlled discharge of the substance when the compartment is tipped to the position shown in Figure 5.

It will be appreciated that in order to minimise weighing errors it is generally desirable to have relatively low friction between the sliding surfaces of the compartment and the weighing device, to arrange for the links to be as near horizontal as possible during weighing, and to have long links so as to minimise the angle of inclination of the links during weighing and thereby minimise the vertical component of the draft force.

Claims

1. A conveying apparatus comprising a plurality of compartments each adapted to support an object or substance to be weighed and conveying means for conveying the compartments past a weighing location at which the compartments may be at least in part supported on a weighing means, the conveying means including a series of cross-members with each compartment coupled to the cross-member adjacent that compartment by a respective linkage and each linkage being pivotally connected to the conveyor and to the associated compartment by pivotal connections having their pivot axes lying in a common plane which at least during weighing lies at not more than ten degrees or so to the horizontal.

2. A conveying apparatus as cl&rned in Claim 1 in which the cross-member leads the compartment to which it is coupled.

4 GB 2 110 393 A 4

3. A conveying apparatus as claimed in Claim 1 35 in which the cross-member follows the compartment to which it is coupled.

4. A conveying apparatus as claimed in Claim 2 or Claim 3 in which the cross-member lies at or close to the adjacent end of the compartment.

5. A conveying apparatus as claimed in any preceding claim in which the pivot axes are spaced apart in the direction of movement of the compartments past the weighing location.

6. A conveying apparatus as claimed in any preceding claim in which the pivot centre to centre length of the linkage approaches the pitch spacing of the cross-members.

7. A conveying apparatus as claimed in any of Claims 1 to 5 in which the pivot centre to centre 50 length of the linkage lies between about 1/8 and 7/8 of the pitch spacing of the cross-members.

8. A conveying apparatus as claimed in any preceding claim in which the, or some of the, links in the linkage house one or more buttons or the 55 like which may be displaced by manual or other means to carry information relating to the contents of the associated compartment or of a compartment having a fixed relationship to that compartment.

9. A conveying apparatus as claimed in any preceding claim in which the compartments are adapted to be partially supported by catch means acting on or carried by the conveying means or by components carried by the conveying means or moving at a fixed relationship with the conveying means.

10. A conveying apparatus as claimed in any of Claims 1 to 8 in which each compartment is supported by a peg or other member protruding sideways of the compartment and arranged to slide or roll along a fixed surface, so supporting the compartment, except where it is desired to weigh or discharge the contents of the compartment.

11. A conveying apparatus as claimed in any of Claims 1 to 8 in which each compartment is supported by a catch or other member mounted on or acting on another component located alongside the compartment and carried by the conveying means.

12. A conveying apparatus as claimed in any preceding claim additionally including the weighing means for registering the weight of a compartment and its contents, the arrangement being such that during weighing the centre of gravity of the compartment and its contents is substantially directly above the effective weight sensitive area of the weighing means.

13. A conveying apparatus as claimed in any preceding claim in which the apparatus also includes means for rotating objects in the compartments to facilitate a comprehensive assessment of other characteristics of the objects at one or more additional locations in the apparatus.

14. A conveying apparatus substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

15. A fruit-grading installation including conveying apparatus as claimed in any preceding claim.

Printed for Her Majesty's Stationery Office by the Courier Press. Leamington Spa, 1983. Published by the Patent Office 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.

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