CA1281002C - Containers - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

CONTAINERS

A lever lidded container has a lever ring moulded from plastics material to comprise an annular flange engaged with the container body, and a frustoconical portion extending radially and axially in relation to the annular flange, towards the interior of the container, to support a cylindrical receiving portion which engages with the plug portion of a lever lid. The container body may be moulded from plastics material or formed from sheet metal.

Description

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CONTAINERS

This inventlon relates to lever lid containers and more particularly but not exclusively to a lever rln~ attachable to the container body and adapted to receive a plug lid wh~ch may be progress1vely 12Yered out of the ring to open the container.

Lever lld tins have been used by the palnt trade for many years. They are usually made of t1nplate and comprise a body having a bottom end;
a cyl~ndrlcal s~de wall having a s~de seam which may be a folded and soldered s~de seam or a lap welded side seam; and a lever r1ng which lo ~s attached to the top of the s~de wall by a double seam. The plug portion Qf a lever lid ~s frict~ona11y held in the ring.

The water based pain~s now widely used have subjected the ~inplate lever ring to ~d much greater risk of corroslon especially at the . worked surfac2s and cut edges of the ring disposed ins~de the container headspace. It ls therefore desirable to provide a lever ring which can survlve the corros~ve environment in the container~
~:, ` Convent~onal t1nplate lever rings so~prise an annular cover hook for :~ double seaming, a chuck wall depending from the inter~or of the cover hook,- a folded portion suppcrting a flared portion extendlng from the ~: 20 chuck wall rad~ally and axially back concentrically within the chuck wall to a second fold portion from which depends a cylindrica1 lid receiving por~ion. The flared por~ion thus holds any 11d F~tted up at a level substantially ~lush with the top of the con~ainer body givlng a neat appearance and access for ~nsertion of a leYer used to remove the lid ~rom the ring.
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:~ However this arrangement of the flared portion presents a posslb~l~ty , ~;

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' that the axially applied forces used to push the lid into the ring will crush the flared portion, so closing the aperture defined by the lid receiving portion and making it more difficult to fit the lid. If the closed container is subjected to abuse, of the kind which is tested by the usual drop tests, the hydraulic pressure within the container acts on the lid which in turn passes the hydraulic force on to the flared portion which may yield beyond its intended shock absorbing flexure to p~rmit the lid to be forced out of the ring.

Thus broadly, the invention pertains to a lever ring Eor a container body and adapted ~o receive a plug lid removable from the ring by means of a lever. The ring is moulded from a plastics material and comprises an annular flange adapted to fit in an open upper end of the container body and to engage with the interior surface of the container body, with a flared portion and a ring portion adapted to receive and grip, when in use, a plug portion of a plug lid. The f~area portion extends from the upper end of the annular flange radially and axially into the ring portion in the downward direction inwardly of the ~ 20 container body, whereby the flared portion permits easy entry of ,~ the plug portion of the plug lid and thereafter firm retention ; of the lid.

The annular flange may be round, rectilinear or of other shapes complementary to the side wall to which it is to be fitted. In each case the flared portion permits easy entry of the plug portion of a lid and thereafter firm retention of the lid.

- The annular flange preferably has a first annulus engageable with the interior surface of the container body, a second annulus in spaced relationship within the first annulus and a plurality of webs joining the first annulus to the second annulus. This composite annular flange has structural rigidity to survive top and side loading.

The flared portion may be frustoconical and extends radially and axially into the annular flange at a preferred angle of approximately 60 to the axis of the lever ring.

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A collar portion may surround the annular flange in order to prevent the annular flange being push~d entirely into the container body.

In one embodiment the ring portion is a hollow cylinder and extends ~n a direction parallel to the axis of the lever ring to each side of the inner periphery of the flared portion. The hollow cy7inder may have : an outwardly flaring mouth surface to assist entry of the plug lid into the cylindrical surface.
., ~: In another embodiment the ring portion comprises a cylindrical flange ~ 10 of internal diameter to permit easy entry of the plug portion of the : lid and a throat portion of internal diameter adapted to seal with the plug portion of the 11d.

~; . In a further embodiment the annular flange ls substantially rectilinear ir outline to fit within the complementary arrangernent of side walls of d container body.

When ~he lever ring has a round annular ~lange, drive receiving means, ~: such as drive pegs ups~anding from the flared surface, may be proviâed : ~ to permi~ spin welding. An annular projection may depend fr~m the ~: collar portion, to surround the annular flange for engagement wlth the `~ 20 side wall of the container by spin welding.
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., If desired, a lug portion may depend from the collar to support ~
pivot head extending laterally uf the lug to permit fixing of a handle to the lever ring.

In another aspec~ the invention provides a lever r~ng ~s hereinbefore -~ ~ described, fitted with a lid having a flange outs~de the r~ng portion;
a plug por~ion extending from the inner periphery of the flange through the ring portion; an annular bead of the plug portion snap fitted against the interior of ~he rlng por~ion; and a closure panel spanning the plug portion.

In a further aspect the invention provldes a lever r;ng as .,~ .
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hereinbefore described when adhered to a me~al side wall of a container body or alternatively spln welded to a side wall of plastics material.

Yarious embodimen~s of the invention will now be described by way of example and with reference to the accompanylng drawings~ in which:-Figure l is a side YieW in cr~ss sect70n on a diameter of a prior art tinplate lever ringi Figure 2 is a side ~iew in cross sectiDn Dn a ~iameter of a first embDdiment o~ a lever r;ng according to this ~nvent~o~;
Figure 3 is a side v;ew ln cross section of a second embodiment o~ the lever r;ng when fitted on a container with the lid fitted;
Figure 4 is a ~ide view of a third embodiment of a lever r1ng : according to the invention;
Figure 5 is a front view of the embodiment of Figure 4;
Figure 6 ~5 an under plan view of the lever ring oF Figure 4;
Figure 7 ;s a fragmentary section on l;ne A-A' in F19ure 6;
Figure 8 ;s a fragmentary section on line B-B' in F;gure 6;
F;gure ~ ;s a side elevation of a round metal container sectioned on a diameter indicated as line C-C' in Figure 11;
Figure lO is a side elevat10n of the lever ring shown ln Figure 9;
Figure 11 is a plan view of the lever ring shown in Figures 9 and lO;
Figure lZ (a) (b) and (c) respectiYely show sectioned side elevation, plan and sectioned end views of a rectangular embodiment of the lever ring;
Figure 13 is a side elevation of a part of a container fitted with a further embodiment of the ring and lid sectioned on a diameter; and . Figure 14 is a plan view of the container ring and lid of Figure 13.

In Figure l the prior ar~ lever ring comprises an annular cover hook l for double seaming ~o a container body (not shown). A chuck wall 2 depends from the inner periphery of the cover hook l and extends to a :

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folded portion 3 which supports a flared portion 4 extending from the folded portion 3 radially and axially in a generally upward direction as shown to a second fold portion 5 from which depends a cylindrical lid receiving portion 6. ~hilst the tinplate ring is relatlvely rigid during the forcin~ of a plug lid into the lid receiving portion 6 there would be a risk that if such a ring were made of plastics material any flexure oF the flared portion 4 will tighten the lid receiving portion onto the plug lid because the flared por~ion is retained against outward spread by the material of the container lo body. Any hydraulic pressure developed by abuse of a filled container is liable to distend the flared portion 4 so loosening the lid.

In Figure 2, the first embodiment of a lever ring according to the invention is moulded from a plas~ics material to have an annular flange 7 engageable with the interior surface of a container. A
substantially frustoconical portion 8 extends from one end of the annular flange 7 radially and axially in relation to the flange to ~ support a cylindrical portion 9. The cylindrical portion 9 is adapted : to rece1ve when in use a plug portion of a plug lid. ln contrast to Figure 1 the ~lared portion of the substantially frustoconical portion of Figure 2 extends downwardly as shown so that during fitting of a lid, such as is shown in Figure 3, any elastic yielding of the frustoconical shape assists entry of the plug portion of the lid into the cyllndriral portion 9.

In Figure 3 a second embodiment o~ the lever ring is depicted which has a collar portion 10 which abu~s the end of the container body 11 to prevent the lever ring entering entirely into the container body.
The rest o~ the lever ring of Figure 3 operates in exactly the same way as the lever ring of Figure 2 so like parts are indicated by the same numbers.

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In Figure 3 the contalner depicted is a plastics moulding comprising a bottom wall 12 and a side wall 13 upstanding from the periphery oF the bottom wall. ~he annular flange 7 o~ the lever ring is a s1iding fit in ~he mouth of the side wall 11 and abutment of the collar portion lO
with the end of the side wall ll ensures that the annular f1ange is squarely entered into engagement wlth the body. This arrangement ensures that any adhesive used to attach the lever ring to the body is only subjected to a shear s~ress. This is advantageous because adhesives are usually stronger in the shear mode of stressing than ~n other modes such as uniaxial tension or peeling. Various 30ining techniques may ~e used to achieve ~hi~ benefit; for example solvent welding, preapplied adhesives, spin welding, or ultrasonic welding 1f the container body is of a plas~ics material.

In Figure 3 the collar portion lO is spin welded to the end of the side wall ll, the annular flange 7 serving to locate the plastics lever ring in the side wall ll during spirning to effect the weld.
Alternatively such a lever ring may be fixed to a side wall of a container by spin welding by a spin weld between the annular flange 7 and the interior of the side wall so that the bond created is, when in use, in the preferred shear mode of stress and not subject to an undesirable peeling mode of stress.

If the container body is metallic, adhesive bonding or spin welding may still be used but it may be found necessary to apply a pr;mer coating o~ plast;cs material to the metal to be adhered to the annular flange. The primer coatings may be in the form of proprietary adhesion promotors. Alternatively metal prelaminated with plast~cs film or lacquer may be used so that the joint is effected by a process akin to heat sealing.

The adhesive bond of plastics ring to container body, may if desired, 0 be augmented by providing snap-fi~ means on ring and body.

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In Figure 3 the l~d 14 comprises a flange 15, a plug portion 16 dependent from the inner periphery of the flange and a dished closure panel 17. The plug portion 16 is provided with a bead 28 which snap fits under the cylindrical por~ion 9 of the lever ringO It will be readily understood that any hydraulic pressure generated by abuse of a filled container will exert an opening force on the lid 14. The engagement oF the bead 18 and plug portion 16 with ~he cylîndrical portion will transmit thls hydraulic ~orce into the frustoconical portion 8 which may bulge and thereby absorb the shock load. However any bu~ging o~ the frustoconical portion will impose a co~pressive hoop force on the cylindrical portion 9 so tha~ the plug portlon of the l~d is gripped more tightly.

However the usual progressive use of a lever at sPveral points under : the flange of the lid against the oollar lO as fulcrum perm1ts removal of the lid from the lever ring.

Figures 4 to ~ generally depic~ a preferred embodiment of the lever ring from the collar lO of whlch depend a pair of l~gs 18 ~hich support a pair of diametrically opposed pivots l9 which permit : attachmen~ of a handle to ~he lever r~ng. Wh~lst the p1vots are desirab1e on the larger sizes of paint containers they are not essential on smaller sizes of container.
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The lever ring depicted in Figures 4 to 8 functions in like manner to the lever rings of Figures 2 and 3 so like parts are indlcated with the same numbers previously used, namely the collar lO~ from which depends the annular flange 7i the frustoconical portion 8 which extends ~ownwardly and inwardly of the annular flange 7; and the cylindrical portion 9 which is adapted to receive the plug portion of a lid. In Figures 7 and 8 the cylindrical portion 9 is provided with flared entry portion 21.
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In Flgure 7 l~ will be seen that the frustoconical portlon ;s inclined at an angle X to the surface of ~he annular flange 7 therefore being also inclined at an angle of X to the axis of the r;ng. Choice of the value of X, the angle of inclination, requires two considerations. IF one requires the frustoconical portion 8 to act as a strut in compression against hydraulic shock loads, a more acute angle is desirable. If however one requ1res ~he ~rus~ocontcal portion to act as a shock absorber by flexure, a less acute angle is required. As both considerations are desirable, we haYe found that an angle of X=60 is a useful compromise giv1ng r;se to reasonable lid retention and adequate shock absorpt;on for the hydraulic loads arising in standard drop tests.

In Figures 7 and 8 an annular projection 20 is depicted on the underside of the collar portion lO. This projection serves to provide plastics material for spin welding the plastics lever ring to the side wall o~ a container made of plastics material. The projection 20 is not apparent in F~gure 3 because it is flattened durins welding.

In Figures 7 and 8 driving pegs 36, 36A are shown against which the driving force is app1ied to create ~he spln weld. These driving pegs ~0 are optional ln the embodiment of Figure 6 because the driving force could, if desired, be applied to the pivo~s l9 to cause spin welding.
It will be understood by those in the art that various alternative means to receive the driving force could alternatively be provided such as slots in the collar portion 10. Also the projection 20 is optional if the plastics container body has a suitable profile on i~s free edge.

As it ~s customary for the side walls of plastics containers to be relatively thick and for the side walls of metal containers to be thinner, for example 0.25mm, it ~s possible to arrange for the projection to be of such a size that a metal body fits between the pro; ec ti on 20 .' .:

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and the annular ~lange 7 so tha~ the lever ring of Figures 4 to 8 may be fitted to either a plastics body or al~ernatively a metal body.

Wh11s~ a metal body may be of ~he built up klnd having a folded side seam, it i5 desirable that the internal surface of the side wall of the body be smooth and continuous ~n order to facilitate bonding of the annular flange 7 to the side wall. Therefore the now available mash welded side seams are preferred.

Figure 9 shows a can body 22 comprising a lid 14 and lever ring 23 of plastics mater;als such as polyethylene or polypropylene, a metal side wall 24 formed from tinplate or chromium/chromium oxide coated stee1 (known as TFS in the trade), and a bottom wall 25 of like metallic material joined to the side wall by a double seam 26. The m tal side wall 24 is made by bending a sheet metal blank and joining the edges at a flattened weld 27 to make a cylinder with a smooth interior surface and a controlled girth. As the metal cylinder ~s flexible ;t is pulled to a good fit when the plas~ics lever ring 23 is inserted so that a good bond between ring and cylinder may be made by means of an adhesive. Alternatively the bond may be ach~eved by spin welding of the flange 7 of the leYer ring on to a compatible coat~ng (not shown~
on ~he interlor of the cylinder - for example a coating of polyethylene may be used.
, In Figure 10 it will be seen that the collar portion 10 does not have an annual projection of material for spin welding as already descrlbed with reference to Figures 7 and 8. In ~he embodiment of Flgure 9 the annular flange 7 is bonded to the metal side wall 24 because the thickness of the metal side wall wlll usually be too thin to permit a joint between the collar portion 10 and the end edge of the metal side wall.

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In Figure 11 eight driving pegs, denoted 36, are shown arranged around the 1nterior surface of collar port1On 10 between the col 1 ar porti on 10 and ~lared portion 8. The driving pegs are no~ big enough to spoil the desired flexure of ~he flared portion 8. Adequate space is provided between ~he driving pegs 36 to permit insertion of a lever at various positions between the flange of the lid and lever ring to effect progressive pris1ng open of the li`d. The driving pegs 36, or like functioning feature, are necessary if the lever ring of Figures 9, 10 and 11 ~s to be spin welded to the body 22 but not essential if adhesives are used.

Figure 12 shows a further embodiment of the lever ring 30 in which a rectangu1ar flange 31 depends from a flat top panel 32 which overhangs the flange to define a collar portion 33 to limit the entry of the flange into a rectangular can body for bonding in a manner already described. A frustoconical portion 34, centred in the flat top panel 32, extends downwardly into ~he ~lange 31 to suppor~ a cyl;ndrical portion 35 adapted to receive a lever lid such as has already been described.

Whilst lids hav;ng a snap fit bead are preferred because the bead increases the lid's ability to contain pressure within the container ~- by passing hydraulic forces ~hrough the cylindrical portion to the frustoconical portion, lids having no snap fit bead may be used by relying on a tight plug fit engagement in the cylindrical portion if the antioipated pressure on the plug lid is not great.

F1gure 13 shows an upper part of a side wall 40 of a container made of plastics material. A lever ring 41, moutded from a polypropylene, is attached to the side wall 40. A plug lid 42 is fitted ln the lever ring 41.

The lever ring 41 comprises an alternative form of the annular flange : ' : '' : ' 0~

having a first annulus 43 engaged with the side wall 40, a second annulus 44 in conoentric spaced relationship within the first annulus 43, and a plural1ty of webs (one of wh~ch is denoted 45) joining the first annulus 43 to the second annulus 44~ bes~ seen in Figure 14.

A flared portion 46 spans the webs 45 and extends from the end of the annular flange 43, whish carries a collar 47, radially and axially in relation to the annular flange to support a ring portion engaged with the lld 42. The ring portion cGmprises a cylindrical flange 48 upstanding from the inner periphery of the flared portion 46 and a throat portion 49 extend;ng below the flared portion to seal against the plug portion 50 and abut a lateral bead 51 of the plug lid 42.

The lid 42 has ~ flange 52 at the top of the plug portion 50 so that the lid is helld firmly against motion in a vertical direction ~as shown in Figure 13) by engagement of flange 52 and cylindrical flange 48 and by enga~ement o~ lateral bead 51 and throat portion 49. The hoop shape and s;ze Qf throat portion 49 define a sealing surface engaged with ~he plug port~on 50 Df lid 42. This ring por~ion may be somewhat easier to open than the embodiments shown in Figures 3 and 9.

Referring to Figure 149 it will be understood that the combination of first annulus 43, second annulus 44 and webs 45 provides an annular flange of sufficient rigidity to survive top and side load forces.

Whilst a plurality of pegs, such as that denoted 53, may be used ~o deliver the spin welding motion, various other drlve receiving means may be used such as slots moulded in the top surface of ~he lever ring.

Whilst the inven~ion has been described in terms of round or rectangular container bodies9 lever rings usin~ the principles described may be made for containers of various irregular shapes . .
' ~L2~ 30 such as are used for d~corated tins and boxes used ~n the biscuit, tea and confectionery trades. For instance, octayonal and square tins are commonly used.

Whilst le~er rings moulded from polyethylene or polypropylene are desirable for economy, rings may be moulded from other materials. For example Nylon 6 could be used for rings fixed to containers for sol~lent based paints which attack polypropylene or polyethylene.

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Claims (14)

1. A lever ring for a container body and adapted to receive a plug lid removable from the ring by means of a lever, wherein the ring is moulded from a plastics material and comprises an annular flange adapted to fit in an open upper end of the container body and to engage with the interior surface of the container body, a flared portion and a ring portion adapted to receive and grip, when in use, a plug portion of a plug lid, said flared portion extending from the upper end of the annular flange radially and axially into the ring portion in the downward direction inwardly of the container body, whereby said flared portion permits easy entry of the plug portion of the plug lid and thereafter firm retention of the lid.

2. A lever ring according to Claim 1, wherein the annular flange has a first annulus engageable with the interior surface of the container body, a second annulus in spaced relationship within the first annulus and a plurality of webs joining the first annulus to the second annulus.

3. A lever ring according to Claim 1, wherein the flared portion is frustoconical and extends radially and axially into the annular flange at an angle of approximately 60°to the axis of the lever ring.

4. A lever ring according to Claim 1, wherein a collar portion surrounds the annular flange and serves to prevent the annular flange being pushed entirely into the container body.

5. A lever ring according to Claim 4, wherein a lug portion depends from the collar and a pivot head extends laterally of the lug to permit fixing of a handle to the lever ring.

6. A lever ring according to Claim 1, wherein the ring portion is a hollow cylinder and extends in a direction parallel to the axis of the lever ring to each side of the inner periphery of the flared portion.

7. A lever ring according to Claim 6, wherein the hollow cylinder has an outwardly flaring mouth surface to assist entry of the plug lid into the cylindrical surface.

8. A lever ring according to Claim 1, wherein the annular flange is substantially rectilinear in outline to fit within the complementary arrangement of side walls of a container body.

9. A lever ring according to Claim 1, wherein drive receiving means of the ring permit spin welding.

10. A lever ring according to Claim 9, wherein an annular projection depends from the collar portion, to surround the annular flange, for engagement with the side wall of the container by spin welding.

11. A lever ring according to Claim 1 wherein the ring portion comprises a cylindrical flange of internal diameter to permit easy entry of the plug portion of the lid and a throat portion of internal diameter adapted to seal with the plug portion of the lid.

12. A lever ring according to Claim 1, when fitted with a lid having a flange outside the ring portion, a plug portion extending from the inner periphery of the flange through the ring portion, an annular bead of the plug portion snap fitted against the interior of the ring portion, and a closure panel spanning the plug portion.

13. A lever ring according to Claim 1, when adhered to the metal side wall of a container body.

14. A lever ring according to Claim 1, when attached to a side wall of plastics material of a container body.