GB2276604A - Device for dispensing fluent material from a collapsible container - Google Patents

Abstract

A device for dispensing a viscous medium from a collapsible container such as a tube comprises a housing 11', and anvil 12' having an extended working surface thereon; and extruder 40 mounted at one end of the working surface, the extruder having an outer face remote from the anvil and an inner, working, face; the extruder being movable relative to the anvil so as to provide, at least initially, a wedge shaped working volume with its narrow end in the region of the hinge 17' and a loading means 41 whereby a load can be applied to the extruder to cause the working face to be brought into, and maintained in contact with, a flexible tube containing extrudable material located in the working volume so as to compress the tube and extrude material therefrom. The extruder may be a rigid member and the loading means may serve to apply a load to the extruder at a point lying at a fixed distance from one end of the extruder (Figure 1). Alternatively the extruder member may be flexible and the loading means, in the form of a handle operated roller or pad (57, Figures 5, 6), may serve to provide a rolling action on the extruder. The anvil can be mounted on the housing by means of at least one support incorporating resilient loading means (54, Figure 5) acting between the housing and the anvil to bias the anvil generally towards the extruder. The extruder may be a curved steel plate (79, Figure 7), with a compression spring biassing its upper end towards the anvil, the plate being loaded towards the tube by a handle, screw, shoe device (91, 86, 89, Figure 7). <IMAGE>

Description

EXTRUSION DEVICE This invention relates to an extrusion device. In particular it is concerned with a device for extruding paste or paste like material or other viscous medium from a deformable tube. Such tubes are widely used for materials such as toothpaste, adhesive, sealant, cosmetics and pharmaceutical materials. Deformable tubes extending from a closed to an openable end are readily manipulated and material extrudable from the openable end when the tube is at least half full. However once the tube is more than half empty its ready deformation to extrude material becomes more difficult. Once the tube is less than about one fifth full it becomes difficult to extrude remaining material with the fingers. This can result in the tube and its remaining contents being thrown away with consequent wastage.

However most of the remaining material can be extruded by rolling the tube up from its closed end or by crushing the tube. Either operation takes time and involves a degree of manipulative skill.

In my co-pending application 9307218.9 there is described an extrusion device for use with a flexible tube of material having a closable vent comprising: a body member including a working surface; a loading means for the tube; guide means located or formed by the body member whereby the loading means, at least while the flexible tube is disposed in a working configuration with the working surface, is maintained in contact with the tube to follow contact path along the tube while applying pressure thereto to cause material originally contained within the tube to be ejected from an outlet thereof when the outlet is open; and driving means for displacing the loading means along the predetermined path.

According to the present invention there is provided an extrusion device for use with a flexible tube of material having a closable vent comprising: a body member housing: an anvil having an extended working surface thereon; an extruder mounted at one end of the working surface, the extruder having an outer face remote from the anvil and an inner, working, face; the extruder being movable relative to the anvil so as to provide, at least initially, a wedge shaped working volume with its narrow end in the region of the hinge between the working face and the working surface; and a loading mens whereby a load can be applied to the extruder to cause the working face to be brought into, and maintained in contact with, a flexible tube containing extrudable material located in the working volume so as to urge the tube in contact with the working surface so as to compress the tube and extrude material therefrom by way of the closable vent.

According to a first preferred version of the present invention the extruder is a rigid member and the loading means serves to apply a load to the extruder at a point lying at a fixed distance from one end of the extruder.

According to a second preferred version of the present invention the extruder is a flexible member and the loading means serves to provide a rolling action on the extruder to progressively reduce the working volume from the one end of the working surface towards the other end of the working surface to the one end.

According to a third preferred version of the present invention or the first preferred version thereof the extruder is a inherently resilient member and the loading means acts on the extruder at a predetermined point so as progressively deform the extruder between an initial relatively undeformed configuration and a final relatively deformed configuration, the initial configuration providing for the application of a loading by the extruder to relative small contact area with a tube located in the working volume and the final configuration providing for the application of loading by the extruder to a relatively large area with a tube located in the working volume.

According to a third preferred version of the present invention or any preceding preferred version thereof the anvil is mounted on the body member by means of at least one support the, or at least one, support being provided with resilient loading means acting between the body member and the anvil to bias the anvil generally towards the extruder.

According to a fourth preferred version of the present invention or any preceding preferred version thereof the loading means incorporates a resilient loading element acting to bias the extruder towards the anvil.

Exemplary embodiments of the invention will now be described with reference to the accompanying drawings of an extrusion device of which: Figure 1 is a sectioned side elevation of a first embodiment; and Figure 2 is a cross-section on section II of Figure 1; Figure 3 is a sectioned side elevation of a second embodiment; and Figure 4 is a cross-section on section IV of Figure 3; Figure 5 is a sectioned side elevation of a third embodiment which is modified version of the second embodiment; and Figure 6 is a horizontal section on section line VI of Figure 5.

Figure 7 is a sectioned side elevation of a fourth embodiment.

Figures 1 and 2 These variously show a housing 11 of a rectangular open side cross section which is of plastics material. The housing 11 serves to locate an anvil 12 which has an extended working surface 13 with an upper end 14 and a lower end 15. The upper end 14 has secured to it leaf 16 of a hinge 17 connected by way of pivot pin 18 to leaf 19 which is secured to extruder 20 at its upper end 21. The extruder 20 is a rigid plate of aluminium alloy having an outer surface 22 and an inner working face 23. The working surface 13 and the working face 23 serve to define a wedge shaped working volume 24 with narrow end 25 in the vicinity of the hinge 17. the extruder 20 is loaded by way of a screw 26 whose inner end 26A contacts outer surface 22 in a socket 27.The screw reacts with the housing by way of a threaded socket 28. the screw 26 is rotatable by way of a hand wheel 29 located outside the housing 11.

In use a tube T (shown in ghosted outline) of tooth paste is positioned in the working volume 24 so that the screw capped end 25 projects slightly from open bottom 30 of the housing 11. The inner working face 23 of extruder 20 is then located to contact the tube T and hand wheel 29 rotated to cause inner end 26A to drive the extruded 20 in a direction to apply an initial loading over the length of tube T by way of inner working face 23. Cap C of the tube T is then removed.

Further rotation of the hand wheel 29 results in contents of the tube T being extruded as required. It has been found that even with relatively viscosity materials on ceasing to rotate the hand wheel 29 following extrusion of the material the flow of material immediately ceases. Consequently it is possible to readily control the amount of material extruded. Once extrusion is completed cap C is replaced.

Figures 3 and 4 The significant differences between the extruder shown and that of Figures 1 and 2 lie in the use of a flexible extruder 40 and the means by which the extruder is loaded. Consequently components in Figures 3 and 4 having the same form and function as in Figures 1 and 2 are given the same reference numeral with the addition of a dash ) and are not described further.

Extruder 40 is of plastics material so allowing for the progressive deformation of the extruder from hinge end T1 to its lower end T2 rather than, as was the case with the embodiment of Figures 1 and 2 with the simultaneous loading of virtually the entire length of the tube T.

The means for deforming the extruder 40 takes the form of a roller 41 with a pair of toothed section, respectively sections 42A, 42B. The toothed sections 42A, 42B engage with racks, respectively racks 43A, 43B, mounted on an inner wall of housing 11'. The roller 41 is rotated by handwheel 45 located outside the housing 11'.As described in connection with Figures 1 and 2 a tube T' is located in working volume 24' The roller 41 is then located as shown at the upper part of the housing in the vicinity of the upper end of the tube T. The hand wheel 45 is then rotated to cause toothed section 42A, 42B, while engaged with racks 43A, 43B, to roll downwardly causing a degree of local distortion of the extruder 40, and so of the tube T, with consequent extrusion of material from the uncapped end of the tube T.

Figures 5 and 6 These show an extrusion device similar in many respects to that described in connection with Figures 3 and 4. Components shown in Figures 5 and 6 which are similar in form and function to those described in connection with Figures 3 and 4 are given similar references to those used in Figures 3 and 4 with the addition of a dash (')and are not discussed further.

Body member 11' is of square section of rigid plastics material. Anvil 50 is floatably mounted on wall 51 of the body member 11' by way of six support columns 50A to 50F. Only column 50A is hereafter described since the remaining columns 50B to 50F are similar in form and function to 50A. Inner end 52 of column 50A is secured to anvil 50. Outer end 53 of column 50A extends through a slot in wall 51. Compression spring 54 acts between the wall 51 and the underside of anvil 50 to resiliently bias the anvil 50 away from the wall 51. The anvil 50 has an extended working surface 55 with an upper end 56 and a lower end 57 and a longitudinal axis Al.

Extruder 40' is a strip of flexible plastics material having an outer surface 22' and an inner working face 23. The extruder 40, has an upper end 21' which is pivotably coupled to the body member by way of a hinge 17'. Inner working face 23A of the extruder 40' and the working face 55 of the anvil 50 serve to define a working volume 24' with narrow end 25' in the vicinity of the hinge 17'.

The extruder 40' is loaded by way of a pressure pad 56 mounted on a block 57 which incorporates an aperture 30 housing a rod 58 on which is mounted a pinion 59. The pinion 59 can rotate relative to the block 57 to cause the block 57 and so the pressure pad 56 to be driven by means of hand wheel 60 along rack 61 so as to cause the block 57 to be driven along axis A2 parallel to axis Al between top location L1 and bottom location 12.

In use the hand wheel 60 is operated to draw the block 57 and so pressure pad 56 to their top location L1. A tube T containing food paste material (tomato paste) is positioned in the working volume 24' so that shoulder 161 of tube T" seats on fork 62 in the body member 11' to provide for tube outlet 63 (covered by screwed cap 64) to project slightly from bottom end 65 of the body member 11'.

When material is to be extruded from tube T" the cap 64 is removed to open outlet 63 and the hand wheel 60 is rotated to drive the block 57 downwardly along axis A2 so that pressure pad 56 slides onto the extruder 40t urging the extruder 40, into contact with upper end T1 of the tube T". The extruder 40' being flexible only transmits pressure on the tube T" in the region where the pressure pad 56 acts on the extruder 40'. The anvil 50 is mounted to float on the columns 13A 13F under the action of the compression springs provided on each column (such as spring 17 on column 13A).The spring rate of the springs is chosen so as to ensure that the anvil 50 under the tube T" in the vicinity of the pressure pad 56 (that is to say where the extruder bears most closely on the tube T) yields causing the anvil 50 to pivot about an axis X perpendicular to axis Al and to the plane of the paper as shown in Figure 5. It has been found that effective extrusion of material is improved by providing for a degree of movement in the anvil 12 as the pressure applied from the pressure pad 28 to the tube T by way of the extruder 21.

Figures 7 and 8 This shows an embodiment of the invention where the extrusion of material from a tube is carried out by means of a surface of a resilient member and the surface is caused to deform progressively along the length of the tube from a starting position where the surface is in contact with a small region of the tube to a final position where the surface is driven into contact with the greater part of the tube to a position near the nozzled end of the tube. This embodiment provides a simple device able to extrude the greater part of the contents of a tube. Housing 71 of square cross section of plastics material. The housing 71 serves to locate an anvil 72 which has a working surface 73 with an upper end 74 and a lower end 75. The upper end 74 is located some way below upper end 76 of the housing 71 so as to leave a gap G between end 76 and axis 77 of column 78.The column 78 serves to locate upper end of extruder 79 by way of aperture 80 in upper end 81 of extruder 79. The extruder 79 is in the form of a curved steel plate whose longitudinal profile is curved so as to enable the extruder 79 to function as will be described in more detail hereafter.

The column 78 serves to locate a compression spring 82 which acts to resiliently bias the upper end 81 of the extruder 79 towards end 83 of column 78. In this way the upper end 81 is provided with a degree of floating motion relative to the anvil 72.

The anvil 72 and the extruder 79 serve to define a wedge shaped working volume 84 with narrow end 85 in the vicinity of the end 83 of column 78.

The extruder 79 is loaded by way of a screw 86 whose inner end 87 contact outer surface 88 of extruder 79 by way of shoe 89. The screw 86 reacts with the housing 71 through a threaded socket 90. The screw 86 is rotatable by way of handwheel 91 outside the housing 71.

To set the device up for use the handwheel 91 is rotated to enable extruder 79 to act under its inherent bias to move outwardly in the direction of the arrow A as the shoe is drawn to the right as seen in Figure 7. Once the working column 84 is sufficient size a full tube T (shown in ghosted outline) of tooth paste is positioned in the working volume 84 with its upper (closed) end in the gap G.

The handwheel 91 is then rotated in a direction to drive the extruder towards the tube T. The curvature of the extruder 79 is such that in this initial phase of loading the tube T only the upper end 81 of the extruder contacts the upper end of tube T and serves to retain the tube against the upper edge of the anvil so preventing any tendency of the tube to drop out of the device while the tube is still relatively full. With cap C of the tube removed a small amount of rotation of hand wheel 91 displaces the extruder to a sufficient extent to squeeze the upper part of the tube T so as to displace toothpaste from the tube T. Once rotation of the handwheel 91 is stopped no further extrusion occurs and the cap C can be replaced.

Thereafter paste can be extruded from the uncapped tube as required. The curved shape of the extruder and its inherent resilient ensures that the tube is progressively emptied. The part of the tube above the contact region with the extruder is maintained pressurised by the extruder 79 so that paste in the tube is compelled to be displaced towards and eventually out of nozzle N of the uncapped tube. It has been found that the device serves to empty nearly all of the tube contents so providing for a minimal wastage of the paste.

The embodiment of Figure 7 is readily operated to remove an emptied tube T and to insert a fresh one.

Driving means In the exemplary embodiments a simple lead screw or roller is used to displace the roller distorting the tube. A wide range of alternative driving means can be used where appropriate such as a lever, a rack and pinion, a pantograph or a reciprocable piston rod. Whatever means is used can be powered manually or by electrical, hydraulic or other powered means. In addition the roller of the second embodiment (described in relation to Figures 3 and 4) or the block of the third embodiment (Figure 4 and 5) can be replaced by a plurality of rollers.

Claims (8)

1An extrusion device for use with a flexible tube of material having a closable vent comprises: a body member housing: an anvil having an extended working surface thereon; an extruder mounted at one end of the working surface, the extruder having an outer face remote from the anvil and an inner, working, face; the extruder being movable relative to the anvil so as to provide, at least initially, a wedge shaped working volume with its narrow end in the region of the hinge between the working face and the working surface; and a loading mens whereby a load can be applied to the extruder to cause the working face to be brought into, and maintained in contact with, a flexible tube containing extrudable material located in the working volume so as to urge the tube in contact with the working surface so as to compress the tube and extrude material therefrom by way of the closable vent.

2 - An extrusion device as claimed in Claim 1 wherein the extruder is a rigid member and the loading means serves to apply a load to the extruder at a point lying at a fixed distance from one end of the extruder.

3 An extrusion device as claimed in Claim 1 wherein the extruder is a flexible member and the loading means serves to provide a rolling action on the extruder to progressively reduce the working volume from the one end of the working surface towards the other end of the working surface to the one end.

4 An extrusion device as claimed in Claim 1 wherein the extruder is a inherently resilient member and the loading means acts on the extruder at a predetermined point so as progressively deform the extruder between an initial relatively undeformed configuration and a final relatively deformed configuration, the initial configuration providing for the application of a loading by the extruder to relative small contact area with a tube located in the working volume and the final configuration providing for the application of loading by the extruder to a relatively large area with a tube located in the working volume.

5 An extrusion device as claimed in any preceding claim wherein the anvil is mounted on the body member by means of at least one support the, or at least one, support being provided with resilient loading means acting between the body member and the anvil to bias the anvil generally towards the extruder.

6 An extrusion device as claimed in any preceding claim wherein the loading means incorporates a resilient loading device incorporated in the loading means and acting to bias the extruder towards the anvil.

7 An extrusion device as hereinbefore described with reference to and as illustrated in Figures 1 and 2 or Figures 3 and 4 or Figure 5 and 6 or Figure 7 and

8.