GB2181711A - Finger assembly for case loader - Google Patents

Abstract

A finger assembly supports up to four moulded fingers (60) in circumaxially spaced relationship so that each finger (60) can guide a bottle (A) dropped downwardly through a pocket defined by four such finger assemblies in a packing case loader. Each finger (60) has a spoon shaped lower end designed to preclude destructive reverse bending of the moulded finger as a result of interference with a case (C) or other impediment. The fingers have radially inturned upper ends for pivotably supporting the fingers in sockets formed between a holder (140) and a finger retaining means (150) secured thereto by a finger retaining means (170). The fingers (60) may be biased by individual return springs and may move laterally at least slightly to accommodate misalignment between them and the case. These springs maybe defined in the form of petals (114a to d) or leaves integrally formed in a plastic part (180) with a central opening (180a) such that this part can be mounted to the lower face of the retaining member (150) and be held in place by the same retaining member fastener (170) as used to assemble the holder (140) and the retainer (150). <IMAGE>

Description

SPECIFICATION Finger assembly for case loader Description The invention relates generally to finger assemblies for case loaders, especially those of the type which include a grid assembly for handling groups of articles to be loaded into upwardlyopen packing cases fed to a loading station belowthe grid. The invention deals more particularly with an improved finger assembly arrangement for such a grid forforming article guiding funnels and to an improved mouldedfingerforuse in such a finger assembly.

In accordance with the invention there is provided a finger assemblyfor a case loader including a finger holder, means for mounting the holder on the loader, a finger retaining means for releasably mounting the retaining membertothe holder, the holder and retaining member being disposed one abovetheother to define spaced finger sockets therebetween spaced around an axis, the retaining member having convex socket portions, a plurality offingers having radially inturned upperends of complementary concave cross-section for pivotally supporting the fingers in the finger sockets so that depending portions of the fingers are free to move toward and away from the axis, resilient means for acting on thefingers to urge them individually away from said axis to locate the fingers in normal positions wherein the fingers ofthe assembly cooperate with fingers of other such finger assemblies to form pockets through which articles drop to load a case. The finger assembly may include a holder adapted to support up to four fingers in four adjacent corners of four associated pockets or passageways in a typical grid assembly. Each finger holder may be mounted in depending position on one of several parallel rails. Each finger may beableto move toward and away from a normal centered position associated with one of the pockets, and each finger may also be capable of at least limited lateral movement in a direction perpendicularto the plane of such pivotal motion.The fastening means may be a single fastener preferably provided in a central opening defined bythe retainer and threadably received in the holder. A coil compression may be provided on the fastener to urge the retainer member upwardly, or individual finger springs may be provided for each finger. In its preferred form each finger has an upper inturned end portion received on a spherical bearing surface cooperatively defined by the holderand the retainer,thefingerand retainer being complementarily shaped to accommodate the generallysphericallyshapedupperendofthefinger.

The lower end of each finger may be formed with a generally spoon shape such that the front surface is concave and adapted to be engaged by an article dropped downwardly into an awaiting case. This spoon shaped end portion of the finger assures that thefingerwill be easily deformed in a direction to- ward the centre line of each passageway butwill not readily deform in the opposite direction. Finally, a moulded plastic spring member is preferably provided with outwardly projecting petal portions acting like leaf springs to engage the backsides of each of the fingers so as to urgethe individual fingers away from the axis.These petals are adapted to be deformed downwardly and inwardly toward the axis of the fastener and each has an outer end portion engaging one of the fingers at a point spaced well belowthe inturned upperend defining the pivotai socket joint.

Drawings Figure lisa schematic view to illustrate the result of interference between the lower end of a finger30 of an assembly according to the invention and a partition in the packing case Cwith which thefingeris cooperating to load a case. The finger is illustrated in solid lines in its normal position and in phantom lines to illustrate how the lower end of the finger is effected by interference of this type.The article loaded is marked atA; Figure2 is a vertical sectional view th rough afin ger assembly constructed in accordance with the in- vention, only one of up to fourfingers being illustra ted in this view; Figure 3 is a viewfrom the rear of a finger for an assembly of the invention such as that shown in Figure 2, and also illustrates the cross sectional con figuration forthefingerat its midpoint; Figures a view of the finger illustrated in Figure3 but with the finger in a normal solid line position and in a phantom line position wherein the finger is deflected laterally relative to its normal position between the retainer and holder;; Figure 5 is a sectional view taken generally on the line 19-19 of Figure 6; Figure 6is a view illustrating the holder configuration for an assembly according to the invention; Figure 7 is a sectional view taken generally on the line 21-21 of Figure 6; Figure 8 is a plan view of the retainer shown in Figures 2 and 4; Figure 9 is a sectional view taken generally on the line 23-23 of Figure 6; Figure 70 is a sectional view taken generally on the line 24-24 of Figure 8;; Figure 11 is a vertical sectional viewthrough an alternative construction for a finger assembly according to the invention, being generallysimilarto the view of Figure 2, but illustrating two opposed fin- gers out offour possible such fingers in a typical finger assembly, one of these two fingers being shown in an alternative position; Figure 12 is a side elevational view of the one piece moulded spring partdefiningthefourindividualspr- ing petals associated with the fourfingers in thefin- ger assembly of Figure 11; and Figure 13isatop plan view ofthe moulded spring part depicted in Figure 12.

With reference to Figures 1 to 10 and in particular Figure 2, a fingerassembly includes a holder40hav- ing an upwardly open slot 40a for receiving a rail, such as utilized in atypical grid assemblyforuse in a case loader in accordance with the invention. The holder 40 is preferably attached to the rail byfasteners (not shown). The holder 40 best shown in Figure 6, defines downwardly open concave parti spherical cavities40b which cavities are spaced around the vertical central axis of the holder 40 for a purpose to be described.

A retaining member 50 mates with the holder 40 to define sockets, and pivotably receive the upper end portions of the fingers 60 as best shown in Figure 10.

The retaining member50definesfourgenerally spherical protuberances 50b which cooperate with the concave spherical cavities 40b, to define the socketsforso receiving the inner end portions 60b of the moulded plastic fingers 60.

An elongated fastener 70 extends upwardly through a central opening 50a in the retaining member 50 and is threadedly received in a metal insert 42 provided for this purpose in the injectionmoulded plastic holder 40. The retaining member 50 and the holder 40 are preferably anchored together without provision for relative motion. If desired such relative motion might be provided for, and in such event a spring is preferably provided between the head offasteer70 and the retaining member 50 so as to provide for limited relative motion between the re tainer50andtheholder40. In the embodiment shown in Figure 2, however, these members 40 and 50 are anchored securelyto one another by means of an upstanding collar 52 integrallyformed on the upper surface ofthe retaining member 50.This coilar abuts the underside ofthe holder40to provide a predetermined clearance between the undersurfaces of finger inner ends 60b and the spherical convex prot uberance 50b, as well as between the top surface of the inner ends 60b ofthe fingerand the convex cavities 40b of the retaining member40.

Individual finger return springs 44 may be provided between the retaining member 50 and the inside of each finger 60 in order to provide a restoring force for these fingers such that they are urged outwardly away from the axis of the fastener and the finger assembly itself. Thus,the fingers are urged toward positions where they will be engaged by a downwardly falling article in an associated article passageway of the grid. These passageways will correspond to particular cells in a packing caseto be ioaded.Each finger preferably has a configuration such as that shown in Figure 3 wherein the upper end portions 60b projects inwardly toward the central axis of the finger assembly, and in which an inturned portion defines an arcuately curved three dimensional pivot area with a shape complementary to that defined by the parti-spherical socket portion ofthe holder and retaining member. Thus, each finger is free to move between the limit positions illustrated for it in Figure 2. Each finger also includes at least one reinforcing rib and preferably two such ribs 60a are formed integrally as shown.These ribs 60 fit loosely in a pair of slots 50c in each side of the generally four sided retaining member50asbestshown in Figure4.The finger 60 also has a return spring locating lug 60d on its inside surface which lug is spaced below the pivot point defined bythe inner or hooked end 60b. The lower end of the finger 60 is preferably spoon shaped so as to have a concave configuration in both the horizontal and vertical sections. This shape provides the advantages apparent from inspection of Figure 1 wherein one of the fingers illustrated generally at30 is deformed inwardly as suggested bythe phantom lines as a result of upward movement of the case Cat a packing station.The spoon shaped lower end portion of the finger is so configured that deformation of thefingerwill occur in the direction indicated in Figure 1 but wili not be possible in the opposite direction because of the geometry ofthe spoon shaped finger itselfwhich provides structural rigidity when urged in the opposite direction. Thus, the propensity of the fingers to suffer unwarranted deformation after long periods of use in the field will be reduced as a result of the geometry of the spoon shaped lower end portion of the fingers as shown.

Figure 4 illustrates the lateral movement of the finger, provided for when a finger comes into contact with a carbon such as can happen during operation of the case loader. Limited relative motion for the finger 60 is provided for in the event of such interference and the invention contributes to relatively long life ofthefingers inspite of such interference and a reduced incidence in breaking of plastic fingers in the field. As described above with reference to Figure 1, the geometry of the spoon shaped lower end of the finger 60 is substantially identical to the finger 30 in Figure 1. These fingers 60 are preferably made from a rigid moulded material and the springs 44 have a high compression rate so asto provide a retarding force on the falling articles.The degree of retarding force can be varied by simply changing the springs used in a particular application. Colourcoding can be resorted to for the convenience of maintenance workers in replacing springs of one force gradient with springs of a different force gradientorspring rate.

With reference to Figures 11 to 13 and in particular Figure 1 1,there is shown a holder 140 similartothe holder40 in that holder 140 has an upwardlyopen slot 140a for receiving a rail. Fasteners (not shown) attach the holder 140 to such a rail and the holder 140, likethe holder40, hasa bottom surfacedefining downwardly open concave parti-spherical cavities spaced circumaxially around the vertical central axis ofthe holder itself.

A retaining member 150 mates with the holder 140 in a manner similarto that with which retainer 50 mates with holder 40 in the embodiment of Figure 2.

Sockets are defined between the retaining member 150 and the holder 140 to pivotably receivetheupper end portion offingers 60 described previously.

Spherical protuberances 150b cooperate with the concave spherical cavities 140b to definethese sockets, and the inner end portions 60b, of the plastic finger 60, are pivotably received in these sockets as shown in Figure 11.

An elongated fastener 170 extends upwardly through a central opening or bore 1 50a defined for this purpose in the retaining member 150, and the upper end ofthefastener 170 is th readably received in a metal insert 42 providedforthis purpose in the injection-moulded plastic holder 140. In the finger assembly of Figure 11 the head of the fastener 1 70 serves to retain a one-piece moulded spring part 180 in a normal position such as that shown in Figure 11 wherein all of the fingers 60 are biased outwardly with respect to the central axis of the fastener 170 similarto thefingers described previously with refer enceto Figure 2.Figure 12showsthis part 180 as having a generally spherical shape, such shape being provided for the desired degree of bending corresponding to a given restoring force on a particular finger or collection of fingers in a particularfinger assembly. By selecting material of predetermined elastic modulus, such as an elastomericthermoplastic urethane, a desired spring forcefora particularfinger assembly application can be achieved. Different spring parts can befabricated so as to achieve dif- ferent restoring forces in a particular application, and these springs colour coded so as to allow convenient replacement when necessary.

A one piece plastic spring part 180 is shown in some detail in Figures 12 and 13 wherein four leaf spring petals 144a, 144b, and 144d are shown in spaced relationship around the axis and a centre opening 180a through which thefastenershank 170 is adaptedto pass in anchoring the plasticspring part 180 in position as shown in Figure 11.

Figure 12 illustrates the psirng part 180 in its unstressed spherical configuration, and in Figure 11 the fingers are shown held in their respective inner and outerlimit positions so asto deform the legsor petals 1 44a-1 44d and thereby exert a restoring force on the fingers 60 which force is proportional to the degree of deformation of these spring petals between these two positions. As a particularfinger (for example the right-hand finger in Figure 11) is biased inwardly by a downwardly dropping article in an associated pocket or passageway ofthe grid, the finger 60 will be moved from the solid line position shown toward the broken line position shown in Figure 11.This causes further deformation of plastic spring petal 1 44b, and the restoring force exerted by this depending petal 144b causes thefinger 60 to be biased towards the solid line position shown much liketheindividual coil springs 44 in the finger assembly described above with reference to Figures 2to 10.

Stillwith referenceto Figure 12,upstanding lugs 180b and 1 80e are provided in the top surface of the plastic spring part 180 so as to mate with openings in the lower end portion of retaining member 150 as suggested in the phantom lines of Figure 13.Since the plastic spring part 180 is provided with the four self-spring petals 144a-144d ata non-symmetrical spacing with reference to the axis of the fastener upon which this part is mounted, it is necessary to so locate the legs 180b and 180cthatthis part 180 can only be assembled in predetermined relationshipto the various fingers in the finger assembly. Thesefin- gers are also supported in a non-symmetric relationship relative to the axis of the fastener 170 as described in United States Patent No.4,448,009. The diagonal dimension 180d in Figure 13forth rhombus shaped retainer 150 is such that it is shorterthan the opposite diagonal forthe rhombus shaped retaining member 150 and these legs preclude assembly ofthe plastic spring part 180 in anything otherthanthe proper orientation.

Claims (15)

1. Afinger assembly for a case loader including a finger holder, means for mounting the holder on the loader, a finger retaining means for releasably mounting the retaining memberto the holder, the holderand retaining member being disposed one above the other to define spaced finger sockets therebetween spaced around an axis, the retaining member having convex socket portions, a plurality of fingers having radiallyinturned upperendsofcom- plementary concave cross-section for pivotally sup- porting the fingers in the finger sockets so that dep- ending portions of the fingers are free to moveto ward and away from the axis, resilient means for ac- ting onthefingersto urge them individually away from said axis to locate the fingers in normal posi tions wherein the fingers of the assembly cooperate with fingers of other such finger assemblies to form pockets through which articles drop to load a case.

2. Afingerassemblyaccording to claim 1 in which each finger is elongated has a lower end of general spoon shape such that the front surface which is engaged by an article dropped downwardly into a case in the loader is concave both in vertical cross section and in horizontal cross section, the elongated portion intermediate the upper end and the lower spoon shaped end having a concavefrontsur- face to guide a descending article.

3. Afinger assembly according to claim 2 in which each fingerfurther has a rear surface of convex contour, in which each finger has a modulus of elas ticity and a thickness such that the spoon shaped lower end will strain in bending along a chord line located adjacent to the juncture between the intermediate elongated portion and the spoon shaped lowerend,the bending being accommodated by said finger configuration when the lower end is stressed by a force acting away from the axis and the bending being inhibited by the finger configuration when the lower end is stressed by a force acting toward the holder axis.

4. Afinger assembly according to any of the preceding claims in which the resilient means include individual return springs.

5. A finger assembly according to claim 4 in which the springs are movable laterally.

6. Afingerassemblyaccordingtoanyofclaims 1 to 3 in which the resilient means is a one-piece moulded spring.

7. Afinger assembly according to claim 6 in which the finger retaining means includes an axially extending elongate fastener means and the onepiece moulded spring has a central opening for receiving the elongated fastener so that the fastener securesthemoulded part to a lower surface of said retaining member.

8. Afingerassemblyaccording to claim 6 or claim 7 in which the moulded spring defining part has integrally formed radially outwardly projecting petal portions acting like leaf springs to engage the backside of each finger and to be deformed downwardly by said fingers.

9. Afinger assembly according to claim 8 in which the one-piece moulded deformable resilient spring defining part has an upper surface defining locating means to locate the plastic part relative to thefingerretaining meanssothattheradiallyout wardly projecting resiliently deformable petal portions are aligned with the finger locations in a resulting clusteroffingers provided in afingerassembly.

10. A finger assem bly according to a ny of claims 6to 9 in which the moulded spring defining part has a generally spherical shape in its undeformed condition and in which the part is of a thermoplastic material selected to provide a desired modulus of elasticityto yield the degree of spring force for a predetermined degree of bending required.

11. Afinger assembly according to any of the preceding claims in which each finger socket has a generally spherical bearing surface, each finger upper end having a generally complementary spherical shape such thatthe finger is free to move side-to-side as well astowardand awayform the axis.

12. Afinger assembly substantially as described with reference to and as shown in Figures 2 to 10.

13. Afinger assembly substantially as described with reference to and as shown in Figures 11 to 13.

14. Afinger assemblyfor a case loader comprising finger holder, means mounting said holderon the loader, a finger retaining member in the form of an elongated fastener means for releasably clamping said retaining memberto said holder, said holder and retaining member disposed axially one above the other in cooperating with one another two define circumaxially spaced finger sockets therebetween, a plurality of fingers having radiallyinturnedupper ends for pivotally supporting said fingers in said finger sockets so that depending portions of the fingers are free to move toward and away from said elongated fastener and the axis thereof, a one-piece moulded spring defining part with a central opening for receiving said elongated fastener so that said fast ener secures said moulded part to the lower surface of said retaining member, said moulded spring defining part having integrallyformed radiallyout- wardly projecting petal portions acting like leaf springs to engage the backside of each finger and to be deformed downwardly by said fingers so as to act on the fingers and to urge them individuallyaway from said axis, each downwardly deformed spring petal having an outer end portion engaging one of said fingers at a point spaced below said inturned upper end of said finger, and said retaining member having convex socket portions cooperating with inturned upperfinger ends ofcomplementary concave cross section to provide said pivotally supported fin gers in normal positions whereby they cooperate with the fingers of other such finger assemblies to form pockets through which articles drop to load a case.

15. Acase loading machine having afinger assembly according to any of the preceding claims.