A CLOSURE DEVICE

Abstract: The invention relates to a closure device such as a cone valve (1) for obturating a filling or discharge opening (2) of a container (3) for flowable material, such as powder, comprising at least two initially separate parts (4 and 5) secured together by an interference fit. The closure device (1) has a seating means for mounting a flexible C-shaped external seal means (10), which engages a lip of a hopper outlet for the flowable material. There is also disclosed a plastic substantially flat retaining member 100 (Figure 7) which engages in the cone valve and holds the valve in position in the opening against unwanted movement, particularly during transport.

Description: A CLOSURE DEVICE The invention relates to a closure device, particularly to such a device as is used to obturate a filling or discharge opening of a container for flowable material. Containers such as intermediate bulk containers usually have a discharge opening obturated by a cone valve. Such valves have to be made to a high degree of accuracy, and are often made of solid 5mm stainless or mild steel with a fully welded and ground annular steel backing ring. Such valves are therefore expensive, about £83 for the cone alone owing to its heavy gauge and the cost of forming it, and in addition there is the cost of welding the seal ring, which generally results in some 3m of weld which then has to be ground and polished to a high degree of accuracy for hygienic purposes as the IBC's are often used to store/transport constituents of food or pharmaceuticals. Even so, the welding is seldom 100% owing to the virtual impossibility of welding the sealing ring in what is a confined space, without forming any microscopic cracks or crevices, in which material can in use lodge. However, it is also possible in some circumstances that the cone valve can inadvertently be pulled up into the container, thereby opening an unwanted passage for flowable material. This is particularly so during transport. It is accordingly an object of the invention to seek to mitigate these disadvantages. According to the invention there is provided a closure device for a filling or discharge opening of a container for flowable material , comprising at least two initially separate parts secured together with an interference fit. Suitably, there may be two parts, one of which may comprise an outer part of substantially conical configuration, and the second part may comprise an inner part depending from the outer part and defining a substantially cylindrical skirt part. This provides an efficient construction, particularly as there may be in the closure device, seating means for a seal means. The seating means may comprise two spaced recesses for seating respective mounting parts of a seal means. This provides a relatively simple construction. One recess may be defined by the outer parts of the device and the other recess may be defined by the inner part of the closure device. This again provides a relatively simple yet efficient construction providing for the seal means to be securely mounted. The closure device is suitably annular in plan and the parts may comprise metal, the recesses also suitably being annular, to receive an annular seal. The parts may be formed by rolling or another suitable forming step. It will be understood that the invention relates to a closure device as hereinbefore defined in combination with a seal means, and to a container having an opening obturatable by a closure device and seal combination as hereinbefore defined. There may also be provided a retaining member for use in combination with an obturating device of a filling or discharge opening of a container for flowable material, the member comprising latch means adapted for releasable engagement with part of the obturating device whereby to hold same in position. The latch means may comprise a plurality of spaced apart projections. This is a relatively simple yet efficient construction, particularly where the member may comprise an annular cap adapted for insertion in the obturating device, when the projections may project away from the cap. Suitably, there may be three projections equiangularly spaced, at 120°. This construction provides a positive, uniform mounting of the retaining member with the cap. Preferably the cap may have a substantially flat surface part inclined at about 20° to the vertical, the projections being mounted on the inclined surface part. This again provides a relatively simple, yet effective, construction, particularly where each projection may comprise a substantially rectangular plate. The member, and projections may be of plastic, and the projections may be welded to the cap, particularly by a part of each projection being welded to a particular part of the inclined surface part. The retaining member may also include detent means whereby the member may be releasably engageable with lifting means of a container. This provides for use with a standard stainless steel or mild steel container such as an I. B.C. which has two transverse fork channels, providing the lifting means (and transport means) of the I. B.C. The detent means may comprise a lateral extension having a profile adapted to engage the lifting means on rotation of the member. This is a relatively simple construction. The profile may comprise an inverted V-shape and an edge spring lip extending therefrom. This provides for positive engagement. There may also be provided a retaining member as hereinbefore defined in combination with an obturating device of a container for flowable material. Furthermore there may also be provided a set of parts, comprising a retaining member as hereinbefore defined, and an obturating device for a filling or discharge opening of a container for flowable material, the obturating device having a part for receiving the latch means in releasable engagement. A closure device, seal means, retaining member and container embodying the invention are hereinafter described, by way of example, with reference to the accompanying drawings. Fig. 1 is a sectional view of a closure device according to the invention; Fig. 2 is an enlarged view of part 'X' of Fig. 1; Fig. 3 shows the closure device of Fig. 1 in combination with a seal means, in an outlet or discharge opening of a container such as an I. B.C. ; Fig. 4 shows to an enlarged scale a closure device and seal located in a base of a different container; Figs. 5 and 6 show respectively enlarged details Y and Z of Fig. 4; Fig. 7 is a plan view of a retaining member according to the invention; Fig. 8 is a transverse section through the member of Fig. 7; Fig. 9 is an enlarged view of detail 'X' of Fig. 8; and Fig. 10 is an enlarged view of detail 'Y' of Fig. 8; Referring to the drawings (like parts being referred to by like numerals), there is shown in Figs. 1 - 6 a closure device 1 for obturating a filling or discharge opening 2 of a container 3 for flowable material, such as a powder, comprising at least two initially separate parts 4 and 5 secured together by an interference fit. One part 4 of the closure device 1 is in the embodiment in the form of a substantially conical part which in use is an outer part. The second part 5 of the closure device 1 is in use an inner part, and has a generally cylindrical skirt part 6. The two parts 4 and 5 are of metal and rolled or otherwise formed to the configuration shown. To construct the closure device 1 from the initially separate parts 4 and 5, the second part 5 is pressed into the first part 4, a nose 7 of the second part 5 sliding over and past a nose 8 of the one part 4 and springing into place in a complementary recess 9 in the one part 4, above the nose 8, the natural resilience of the metal enabling this action to take place. The interference fit between the two parts 4 and 5 is what is known as a heavy interference, being about 5mm, whereby the interference fit holds the two parts 4 and 5 securely together. The parts 4 and 5 are thus secured together without the use of additional securing means such as welding, and this enables a relatively light gauge of metal to be used, thereby providing financial saving in construction, and in use not so much power is required to raise and lower the lighter closure device 1 of the invention, as compared with the previous cones. Moreover, as there is no welding, there are no cracks or crevices. Further, the metal being rolled is in any event strong owing to the constructional method, so it does not deform under load. The closure device 1 is used with a seal means 10 which is mounted in two spaced apart recesses 11 , 12 comprising seating means for the seal means. The first or upper (as used) recess 11 is of generally V-shape having a 10° inclined lower wall and the upper part of which is partially closed by a lip or overhang 13 which is a continuation of the nose 8 of the outer part 4 of the closure device 1. The other or lower recess 12 is at the lower edge of the annular skirt part 6 and is defined by a D-shaped profile 14 which forms part of the aforesaid strengthening of the closure device and which also has a 10° upper (in use) inclined wall. The seal means 10 itself is a substantially U or C-shaped moulding suitably of rubber. The seal means is generally annular and has an upper annular enlarged or bulbous part 15 of generally complementary shape to the recess 11. Likewise there is a lower annular enlarged or bulbous part 16 of the seal means 10, of generally complementary shape to the lower recess 12 in the annular skirt part 6. The lower annular part 16 also has an annular toe or lip 17 which is slightly larger in diameter than the discharge opening or outlet 2 of the container 3, hence when the closure device 1 is pulled down firmly in use to obturate the outlet 2, the lip 17 self engages below the container outlet to effect a complete seal. In order to mount the seal means 10 in combination with the closure device 1 , the upper annular part 15 is mounted in the recess 11 before the inner and outer parts 4, 5 of the closure device are pressed together with an interference fit. When the inner part 5, with the seal means 10 in place is offered up to and pressed together with the upper part, a flat surface of the upper annular part 15 of the seal means 10 is tightly compressed between the lip 13 and the V-shaped part of the skirt means defining the V-shaped recess 11 , so locking the upper annular part 15 in place and compressing it tightly so that in use, no foreign bodies, such as dirt, or powder or product can enter the space between the seal means 10 and the skirt means 6, so enhancing hygiene. The lower annular part 16 is engaged in the D-shaped recess 14 by stretching it and forcing it in the D- shaped recess, the thickness of the annular part being greater than that of the "D" so that the annular part 16 is received with a snug fit. The lower annular part 16 can, however, be relatively readily removed manually or automatically such as by vacuum cups attached to pneumatic pistons and cylinders to allow a body 18 of the seal means 10 to be moved away from the skirt 6, the upper part 15 remaining firmly anchored in the V-shaped recess 11 to allow access to the annular space between the inner (as used) surface of the seal means body and the outer surface of a vertical part of the skirt part means. After cleaning, the bulbous part 16 can be forced back into snug, secure engagement in the D- shaped recess 14. Fig. 6 shows the annular lip or toe 17 clipped behind an outlet lip 19 of the container 3, while Fig. 5 shows the closure device part way raised, the seal means thus providing a valve seal itself via its toe or lip 17 (Fig. 4, left hand side). This avoids contamination by powder or product because the closure device 1 can be pushed up the first time it opens and thereafter is not pulled down to re-engage the bottom outer lip of the container until the end of a cycle or complete emptying of the container 3. The bottom engaging ring 17 of the seal means thus acts as the valve. To "valve" fully the closure device 1 is pulled down fully (Fig. 4, right hand side), using for example an expanded probe clamp via a vacuum lock. The hygiene problem is thus sought to be overcome in that the seal means 10 described herein obviates trapping of powder, product and the like foreign bodies between the seal means and skirt part means. Referring now to Figs. 7 - 10, there is shown a retaining member 100 which also acts as a transport cap and/or dust cover, for use in combination with the closure obturating device 1 such as a cone valve of the filling or discharge opening 2 of a container 3 for flowable material, such as a powder, granules, grain (s) or the like, comprising latch means 101 adapted for releasable engagement with part 14 of the obturating device 1 whereby to hold same in position (in the opening 2). The member 100 is plastic, suitably formed by a vacuum forming process, having an annular cap or dome 102 which just fits inside the inner periphery of the cone valve 1 , (Fig. 4), the cap or dome 102 being housed internally of the cone valve 1. The member 100 includes an annular lateral rim or wing 103 including a detent in the form of a V or U-shaped profile 104 and an edge spring lip 105. The cap 102 and the V or U-shaped profile 104 are closed by a flat plate 106 (Fig. 8) secured to the rest of the member 100 as by welding. The cap 102 has an annular flat part 107, inclined at about 20° to the vertical to which is secured as by welding the latch means 101 , in the form of a plurality, in the embodiment three, equiangularly disposed at 120°, projections. The projections 101 each comprise a flat rectangular plastic plate or tab secured at one end to the flat part 107 by welding as mentioned hereinbefore. The projections 101 are relatively stiff, but have a degree of inherent flexibility. The part 14 of obturating device 1 is an internal part in the form of an annular shoulder or ledge at a free edge and which in use is located substantially at the level of the boundary of the opening 2 of the container 3. Externally of the obturating device 1 at the same level as the shoulder or ledge is the base of the ring seal 10 (Fig. 6) which in use clips below the outlet 2, being deformable and elastic. It could thus be forced upwardly (as viewed) which would raise the cone valve 1 and hence open an unwanted opening for passage of material. To obviate this, the retaining member 100 is offered up to the container 3, with the cone valve 1 in position (right hand side of Fig. 4), so that the cap 102 enters below the cone 1. As the retaining member 100 is pushed up (as viewed, Fig. 4) the latch means or projections 101 ride up the inner periphery of the shoulder 14 and then clicks into place on top of the shoulder 14 (Fig. 4). The obturating device 1 is then firmly held down, in position, and cannot be moved upwardly because the plate 106 extends laterally beyond the opening 2 as shown. Thus there is provided a retaining member 100 which acts as a transport cap, and dust cover as the plate 100 prevents dust getting to or from the seal 10. The retaining member 100 is removable, by pulling downwardly, whereupon the projections 101 , on application of a reasonably high force, flex, deform and slide down and out. The cone valve 1 can then be moved as desired. The retaining member 100 may be used with an I. B.C. , of stainless steel or mild steel, which has a pair of transport (fork) channels 107. In this case, the retaining member 100 is offered up as before and pushed horizontally so that the U or V-profiles are parallel to the fork channels and between them. The retaining member 100 is then rotated 90° to clip the lateral spring edge on the bottom surface of the channels 107, so holding the retaining member 100 in position. This operation can be performed manually, or automatically by means of an engage and disengage station using, for example, a suction cup or expansion tyre to hold the cap of the member whereafter the container is lowered onto it to rotate and engage the clips 105.

Claims: CLAIMS 1. A closure device for a filling or discharge opening of a container for flowable material, characterised by at least two initially separate parts (4, 5) secured together with an interference fit. 2. A closure device according to Claim 1 , characterised by two parts (4), (5) , by one (4) comprising an outer part of substantially conical configuration and by the second part (5) comprising an inner part depending from the outer part and defining a substantially cylindrical skirt part (6). 3. A closure device according to Claim 2, characterised by seating means (11 , 12) for a seal means. 4. A closure device according to Claim 3, characterised by the seating means (11 , 12) comprising two spaced recesses, for seating respective mounting parts (15, 16) of a seal means (10). 5. A closure device according to Claim 4, characterised by one recess (11) being defined by the parts (4, 5) of the device (1) and by the other recess (12) being defined by the inner part (5) of the closure device (10). 6. A closure device according to Claims 4 or 5, characterised by the other recess (12) being of substantially D-shape in cross-section. 7. A closure device according to Claim 6, characterised by the recesses (11 , 12) each being annular. 8. A closure device according to any preceding claim, characterised by the parts (4, 5) comprising metal. 9. A closure device according to Claim 8, characterised by the parts (4, 5) being formed by rolling. 10. A closure device according to any of Claims 3 to 9, characterised by a seal means (10) mounted in the seating means (11 , 12). 11. A container for flowable material having a discharge opening obturatable by a closure device according to any one of Claims 1 to 9, or combination according to Claim 10. 12. A retaining member for use in combination with an obturating device of a filling or discharge opening of a container for flowable material, characterised by the member (100) comprising latch means (101) adapted for releasable engagement with part (14) of the obturating device (4) whereby to hold same in position. 13. A member according to Claim 12, characterised by the latch means (101) comprising a plurality of spaced apart projections (102). 14. A member according to Claim 13, characterised by an annular cap (102) adapted for insertion in the obturating device, the projections (101) projecting away from the cap (102). 15. A member according to Claim 14, characterised by there being three projections (101) equiangularly spaced at 120°. 16. A member according to Claim 15, characterised by the cap (102) having a substantially flat surface part (107) inclined at about 20° to the vertical, and by the projections (101) being mounted on the inclined surface part. 17. A member according to Claim 16, characterised by each projection (101) comprising a substantially rectangular plate. 18. A member according to any of Claims 12 to 17, characterised by being made of plastic. 19. A member according to any of Claims 12 - 18, characterised by detent means (105) whereby the member (100) is releasably engageable with lifting means of a container. 20. A member according to Claim 19, characterised by the detent means (105) comprising a lateral extension having a profile adapted to engage the lifting means on rotation of the member, and by the profile comprising an inverted V- shape and an edge spring lip extending therefrom. 21. A retaining member according to any of Claims 1 - 20, in combination with an obturating device of a container for flowable material. 22. A set of parts, characterised by a retaining member (100) according to any of Claims 12 to 21 , and by an obturating device for a filling or discharge opening of a container for flowable material, and by the obturating device having a part for receiving the latch means in releasable engagement.

Inventors: SEMENENKO IVAN, SEMENENKO, IVAN
Applicants: MATERIAL CONTROL ENG LTD, SEMENENKO IVAN, MATCON LIMITED, SEMENENKO, IVAN
Application year: 1995
Main classification: F16K27
IPC codes: B65D90, F16K27