GB2537407A

GB2537407A - Apparatus and method for opening a sealed sack containing particulate material

Info

Publication number: GB2537407A
Application number: GB1506503.0A
Authority: GB
Inventors: Bennison Stewart
Original assignee: PALAMATIC Ltd
Current assignee: PALAMATIC Ltd
Priority date: 2015-04-16
Filing date: 2015-04-16
Publication date: 2016-10-19
Also published as: GB201506503D0

Abstract

An apparatus 101 for opening a sealed sack comprises a housing 102 having a material outlet 103. A support table 104 is mounted within the housing, the support table having a surface 105 for supporting a sack. A blade assembly 108 is mounted within the housing and configured to hold a blade 109 for cutting a sack when located on the support table. A first engagement mechanism 106 is configured to retain the support table in position, and a second engagement mechanism 110 is configured to retain the blade assembly in position. At least one of the engagement mechanisms is configured to be releasable to enable the support table and/or the blade assembly to be removed from the housing. Also envisaged is an apparatus for emptying a sack characterised by a transfer mechanism 111 configured to lift an open ended sack from a support table and move the sack to a separation position. Also envisaged is an apparatus for emptying a sack characterised by a sack retaining structure 112 supported by a support arm 113 driven by a drive mechanism 116 wherein the sack retaining structure is pivotally mounted on the support arm.

Description

TITLE

Apparatus and method for opening a sealed sack containing particulate material

FIELD OF THE INVENTION

Embodiments of the present invention relate to an apparatus and method for opening a sealed sack containing particulate material. In particular, they relate to an apparatus and method for opening a sealed sack containing particulate material in food production and pharmaceutical industries.

BACKGROUND TO THE INVENTION

Automated machinery is known for opening and emptying sacks (or bags). The machinery tends to be complex and difficult to access to cleaning.

BRIEF DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION

According to various, but not necessarily all, embodiments of the invention there is provided an apparatus according to claim 1.

This provides the advantage that the support table and/or the blade assembly may be easily removed from the housing to enable the support table, blade assembly and housing to be maintained and/or cleaned.

According to various, but not necessarily all, embodiments of the invention there is provided an apparatus according to claim 29.

This provides the advantage that the speed of the process of repeatedly opening and emptying sacks using the apparatus may be optimized.

According to various, but not necessarily all, embodiments of the invention there is provided an apparatus according to claim 43.

According to various, but not necessarily all, embodiments of the invention there is provided a method according to claim 54.

According to various, but not necessarily all, embodiments of the invention there is provided a method according to claim 55.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of various examples of embodiments of the present invention reference will now be made by way of example only to the accompanying drawings in which.

Figs. 1A, 1B and 1C show a cut-away perspective view, a cut-away front view 15 and a rear view of an example apparatus 101 for opening a sealed sack containing particulate material; Fig. 2 shows a perspective view of the complete apparatus 101; Fig. 3 shows a detailed view of the blade assembly 108; Figs. 4 and 5 show a front view and a rear view of the support table 104 respectively; Fig. 6 shows a partial view of the apparatus 101 with an alternative support table 104A separated from the first support structure 119; Fig. 7 shows a front perspective partial view of the transfer mechanism 111; Fig. 8 shows a rear perspective partial view of the transfer mechanism 111; Fig. 9 shows the transfer mechanism 111 disassembled from its support structure 115; Fig. 10 shows a starting position for apparatus 101; Fig. 11 shows the apparatus 101 after movement of the transfer mechanism 111 such that the sack retaining structure 112 is positioned above the sack 1001A; Fig. 12 shows the apparatus 101 with the blade assembly 108 in its retracted position; Fig. 13 shows a partial cross-sectional perspective view of the apparatus 101; Fig. 14 shows the apparatus 101 after the blade assembly 108 has reached its full stroke and cut into the sack 1001A; Fig. 15 shows after retraction of the blade assembly 108 and during oscillation of the support table 104; Fig. 16 shows the apparatus 101 during a process of shaking the sack 1001A; Fig. 17 shows the apparatus 101 with transfer mechanism 111 in the sack separation position; and Fig. 18 shows a schematic diagram of an example of a pneumatic circuit including pneumatic cylinders 124, 153, 174 and 504.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION

The Figures illustrate an apparatus 101 for opening a sealed sack 1001A containing particulate material, the apparatus comprising: a housing 102 having a material outlet 103; a support table 104 mounted within the housing, the support table having an upper surface 105 for supporting a sack; a first engagement mechanism 106 configured to retain the support table in position; a blade assembly 108 mounted within the housing 102, the blade assembly configured to hold a blade 109 for cutting a sack when located on the support table 104; a second engagement mechanism 110 for retaining the blade assembly in position, wherein at least one of the first engagement mechanism 106 and the second engagement mechanism 110 is configured to be releasable to enable the support table 104 and/or the blade assembly 108 to be removed from the housing.

As used herein the word "sack" refers to sacks and oblong sealed bags formed of various materials such as plastic sheeting or paper.

Because the support table 104 and/or the blade assembly 108 may be removed from the housing, parts of the removed component may be easily accessed for cleaning. Also by moving the component(s) out of the way, the interior surfaces of the housing 102 are more easily accessed for cleaning.

In the illustrated embodiments, the apparatus 101 also comprises a transfer mechanism 111 configured to lift an open ended sack from the support table 104 and move the sack through an intermediate orientation, in which the open end of the sack is beneath an opposite end of the sack, to a separation position where the sack is separated from the transfer mechanism 111. In such embodiments, the transfer mechanism 111 may comprise a sack retaining structure 112 which is supported by a support arm 113. In such examples, the support arm 113 may be releasably attached to a support structure 115 attached to a drive mechanism 116.

However, in alternative embodiments, the apparatus 101 is not provided with a transfer mechanism 111. In such embodiments, processes that might be performed by the transfer mechanism are performed manually by hand.

In some embodiments the apparatus 101 has a transfer mechanism 111 comprising: a sack retaining structure 112 comprising a support surface 151 for location against a sack and a sack engagement element 152 configured to mechanically engage with a sack located against the support surface 151; a support arm 113 supporting the sack retaining structure 112; a drive mechanism 116 supporting the support arm 113 and configured to rotate the support arm 113 about a first axis 179, wherein the sack retaining structure 112 is pivotally mounted on the support arm 113 to enable the sack retaining structure 112 to rotate about a second axis 156 while the support arm 113 is rotated by the drive mechanism 116.

An example apparatus 101 for opening a sealed sack containing particulate material is shown in a cut-away perspective view in Fig. 1A, a cut-away front view in Fig. 1B and a rear view in Fig. 1C. The apparatus 101 comprises a housing 102 having a material outlet 103. In Fig. 1A and 1B a front portion of the housing 102 has been cut away to show the interior components of the apparatus 101. In Fig. 1A and Fig. 1B only a rear wall 117 and a lower side wall 117A of the housing is shown.

The housing 102 has a second lower side wall which extends from sloping edge 118 of the rear wall 117. The rear wall 117, lower side walls 117A and the front wall 201 (shown in Fig. 2) have bottom edges that extend around the material outlet 103.

A support table 104 is mounted within the housing 102. The support table 104 has an upper surface 105 for supporting a sack. The support table 104 is mounted on a first support structure 119 and a first engagement mechanism 106 is configured to retain the support table in position on the first support structure.

The first support structure 119 may comprise plates 120 rigidly attached to a rotatable shaft 121 which is mounted on bearings 122. Further details of the support table 104 and support structure 119 will be described below with respect to Figs. 4, 5 and 6.

As shown in Fig. 1C, the shaft 121 may be made to rotate by a drive mechanism in the form of a pneumatic cylinder 124 mounted on the outside surface of the rear wall 117 of the housing 102. The piston of the pneumatic cylinder 124 is operatively connected to a lever 125 that is fixed to the shaft 121 so that operation of the cylinder 124 causes rotation of the shaft 121.

Because the support table 104 is mounted on the shaft 121, as described above, action of the pneumatic cylinder 124 causes tilting of the support table about the shaft 121. Consequently, repeated backward and forward strokes of the cylinder 124 cause the orientation of the support table to oscillate. This action may be used to shake a sack when located on the support table.

The apparatus 101 may also comprise side-pressing elements 161 configured to extend upwards adjacent to side edges 162 of the support table 104. The support table 104 is configured to tilt independently of the side-pressing elements 161, which may be held in a stationary position. Consequently the height of the side-pressing elements 161 above the upper surface 105 of the support table 104 oscillates when the table is made to oscillate. As will be described further below, this movement of the side-pressing elements 161 relative to the support table 104 may be used to cause the side pressing elements to impact upon the sides of a sack located on the table 104.

In the present example, the side-pressing elements 161 are mounted from the sloping side wall 117A of the housing 102.

The support table 104 may be provided with slots 163 through which the side-pressing elements 161 may pass during operation.

The housing 102 has an opening 181 positioned between the rear wall 117 and the front wall 201 (shown in Fig. 2) of the housing 102 positioned at the upper end of the support table 104. The opening 181 enables sacks 1001 of material to enter the housing and be located on the support table 104. In the example shown in the figures, a roller conveyor 182 is provided to facilitate movement of sacks 1001 to the opening 181 and onto the support table 104. However, it will be understood that alternative types of conveyors may be used, or mechanisms other than a conveyor may be used for loading the

support table 104.

The apparatus 101 also comprises a blade assembly 108 mounted within the housing 102. The blade assembly 108 is arranged to hold a blade 109 for cutting a sack when located on the support table 104. The upper surface el 05 of the support table 104 is positioned at an angle to the horizontal such that its upper end is nearest the opening 181 and a lower end is nearest the outlet 103. In a forward position of the blade assembly 108, as shown in Fig. 1B, the blade 109 is located at the lower end of the upper surface 105 of the support table 104.

The blade assembly 108 is mounted on a second support structure 126. A second engagement mechanism 110 is configured to retain the blade assembly 108 in position on the second support structure. As will be described in further detail below, with respect to Fig. 3 the second engagement mechanism 110 is configured to be releasable to enable the blade assembly 108 to be removed from the housing.

The second support structure 126 is configured to move the blade assembly 108 during a sack cutting procedure. In the present embodiment, the blade assembly 108 holds a fixed blade 109 and is configured to move it in a chopping action for slicing through an end portion of a sack of particulate material. However, it will be appreciated that other embodiments may employ one or more rotary blades.

The second support structure 126, on which the blade assembly 108 is mounted, comprises a shaft 171 that is mounted to rotate within bearings 172 located towards each end of the shaft 172. A lever 173 is fixed to one end of the shaft 171 and the lever is operatively connected to a pneumatic cylinder 174 mounted on the outer surface of the rear wall 117 of the housing 102. Operation of the pneumatic cylinder 174 provides a force on the lever 173 to rotate the shaft 171 and so rotate the blade assembly 108. The pneumatic cylinder 174 therefore provides the drive mechanism required to move the blade 109 in its chopping action.

In the present embodiment, the bearings 172 are themselves mounted to move with respect to the housing 102. In the present example, the bearings 172 are mounted at a lower end of arms 175 and the arms 175 are pivotally mounted at an upper end to allow the desired movement of the bearings 172. In the present example, the upper end of the arms 175 have bearings 176 which are supported on a shaft 177 that is itself supported in bearings 178 fixed to the walls of the housing 102.

A spring mechanism 203 (shown in Fig.2) is provided to urge the arms 175 to 5 the position shown in Fig. 1B. The spring mechanism 203 may comprise a tensioned spring attached one of its ends to an arm 175 and at the other end to a bracket fixed to the housing 102. A spring mechanism 203 may be provided on one or both arms 175. A stopping bracket 204 is also fixed to the housing 102 which prevents the arm moving past its required forward position. 10 As will be described below, this spring arrangement allows the blade assembly 108 to be used as a stop for positioning sacks on the support table 104, as well as being used to cut those sacks. In an alternative embodiment a stop for positioning sacks on the support table 104 may be provided that operates independently of the blade assembly.

The apparatus 101 of Figs. 1A, 1B and 1C also comprises a transfer mechanism 111. The transfer mechanism 111 comprises a sack retaining structure 112 comprising a support surface 151 for location against a sack 1001 and a sack engagement element 152 configured to mechanically engage with a sack located against the support surface 151. In the present example, the transfer mechanism 101 has four sack engagement elements 152, but it will be understood that this number may be varied.

The transfer mechanism 111 of Figs. 1A, 1B and 1C also comprises a support arm 113 supporting the sack retaining structure 112 and a drive mechanism 116 supporting the support arm 113 and configured to rotate the support arm 113 about a first axis 179. In the present example, the drive mechanism 116 comprises a pneumatic cylinder 153 mounted on the outside surface of the rear wall 117 of the housing 102, a lever 154 to which the cylinder 153 is operatively connected and a shaft 177 to which the lever 154 is fixed. Therefore, operation of the cylinder 153 is arranged to actuate the lever 154 to rotate the shaft 177 about its axis 179 and cause rotation of the support arm 113 about the shaft 177.

In the present embodiment, the sack retaining structure 112 is pivotally mounted on the support arm 113 to enable the sack retaining structure to rotate about a second axis 156 while the support arm is simultaneously rotated by the drive mechanism 116 about a first axis 179 provided by the shaft 116. In the present embodiment, the second axis 156 is parallel to the first axis 179, and both the first axis and the second axis are substantially horizontal.

The transfer mechanism 111 may also comprise a rotation mechanism for causing rotation of the sack retaining structure 112 during rotation of the support arm 113. In the present embodiment the rotation mechanism comprises a slide member 157 retained by a slide support 158, which is anchored to a position on the rear wall 117 of the housing 102. The slide member is rigidly attached to the sack retaining structure 112 and the slide member is configured to slide with respect to the slide support 158. Consequently, when the support arm 113 is rotated, the slide support 158 acts on the slide member 157 and so causes pivoting of the sack retaining structure 112 about the second axis 156.

In the present example, the slide member 157 comprises a pair of parallel bars and the slide support 158 comprises a grooved wheel pivotally mounted on the rear wall 117. The grooved wheel has a circumferential groove on its cylindrical outer surface, and the bars of the slide member extend though the groove on either side of the wheel. In alternative embodiments the slide member 157 may be a single element that extends through an aperture in the slide support, which is pivotally mounted on the rear wall 117. However, in each case the slide member provides a lever action on the sack retaining structure 112 when the support arm 113 moves the sack retaining structure.

In alternative embodiments the rotation mechanism (comprising the slide member 157) may be replaced by a rotation mechanism that may be operated independently of the motion of the support arm 113. In an example, the sack retaining structure 112 may include a pneumatic cylinder configured to provide rotational forces between the support arm 113 and the sack retaining structure 113.

The apparatus 101 may also comprise a pneumatic control unit 100 (shown in Fig. 1C) comprising components, such as valves and some of the sensors necessary for the operation of the pneumatic cylinders that form the apparatus 101. An example of components housed in the control unit 100 is illustrated in the circuit diagram of Fig. 18. It may be noted that for the sake of clarity, pipes from the pneumatic control unit 100 to the various pneumatic cylinders of the apparatus 101 have not been shown in Figs. 1A, 1B or 1C.

The apparatus 101 is shown in Figure 2 with the whole of housing 102 in place. The front wall 201 of the housing 102 may be provided with a window 202 formed of a transparent sheet of material to enable a person operating the apparatus 101 to be able to see inside.

In the present embodiment, the apparatus 101 is provided with the transfer mechanism 111 to lift the opened (and almost empty) sacks 100 from the support table 104. As will be described in detail below, the transfer mechanism may be operated to shake the sacks to further empty them before removing the sacks from the housing 102. In an alternative embodiment, the apparatus 101 is not provided with the transfer mechanism 111. Instead the apparatus 101 is provided with a pair of arm access ports in the front wall 201 to allow a user to manually lift a sack from the support table 104, shake it and move it out of the apparatus. In such an embodiment the access ports may be provided with gloves to protect the user form the material being emptied from the sacks and/or prevent contamination of the material by human contact. The apparatus 101 may also be provided with dual start buttons that must be continuously pressed to maintain the operation of the apparatus. The start buttons may be located on the outside of the front wall 201 and spaced apart so that a user must use both hands to cause the apparatus 101 to operate. In this way, as soon as a user stops pressing one or both of the start buttons the apparatus stops operating and becomes safe for the user to insert their hands through the access ports to shake a sack.

A detailed view of the blade assembly 108 is shown in Fig. 3. The blade assembly comprises a mounting plate 301 on which the blade 109 is mounted. The mounting plate 301 is attached to a pair of parallel plates 302A and 302B which are provided with slots 303 for engaging corresponding spigots 1302 (shown in Fig 13) on the second support structure 126.

The blade assembly 108 is also provided with the second engagement mechanism 110. In the present embodiment the second engagement mechanism comprises two indexing plungers 310, each one fixed to a respective one of the two plates 302A. The indexing plungers 310 are of a known type and comprise a handle 305 fixed to a pin 304 which passes through a body 306 that is fixed to the respective plate 302A, 302B. The pin is sprung loaded to be urged into the forward position as shown in Fig. 3 and the pin 304 may be retracted by manually pulling back the handle 305. The body 306 and handle 305 may have castellated surfaces so that the handle may be retracted and held in a retracted position by rotating it to misalign the castellated surfaces.

One of the plates 302B is shown attached to the second support structure 126 in Fig. 13, which shows a partial cross-sectional view of the apparatus 101. The second support structure 126 includes two plates 1301 (one of which is shown in Fig. 13 and the other may be seen in Fig. 1A) which are fixed to the shaft 171. The plates are provided with spigots 1302 that are dimensioned to enable them to engage with the slots 303 of the plates 302A, 302B as illustrated in Fig. 13. The pins of the indexing plungers 310 locate within holes (shown in Fig. 1A and 1B) formed in the plates 1301. To remove the blade assembly 108 from the second support structure 126, the handles 305 of the indexing plungers are pulled to withdraw the pins 304 from the holes 195 and the blade assembly 108 is then lifted and maneuvered to remove the spigot 1302 from the slots 303. (The movement of the handles 305 in this process is illustrated in Fig. 3 by arrows 307.) The blade assembly may then be completely removed from the housing, for example for cleaning and/or maintenance purposes.

A front view and a rear view of the support table 104 are shown in Fig. 4 and Fig. 5 respectively. The support table 104 is provided with two plates 502 attached to its rear surface 501. In the present example, the two plates are similarly formed and have two spigots 503 on one of their sides for locating in slots (123 in Fig. 6) formed in the first support structure 119. The plates are also provided with holes 510 for receiving pins which provide the engagement mechanism for retaining the support table in position on its first support structure 119.

The support table 104 may be provided with a sack engagement mechanism 504 for retaining a sack in position on the upper surface 105 of the support table 104. The sack engagement mechanism may comprise one or more spikes 505 which may be moveable to pierce a sack when located on the support table. The spike 505 may have an arcuate shaped portion having a pointed end and the pointed end may be arranged to move from a retracted position below the upper surface 105 of the support table 104, upwards above the upper surface of the table and to a fully forward position below the upper surface.

In the embodiment illustrated in Fig. 5, the support table 104 comprises two spikes 505, which have a first end attached to a rotatable shaft 506. The spikes have an arcuate shaped portion which terminates in a pointed end 507. The support table 104 has two apertures 401 and 402 for each of the spikes 505. In their retracted positions (shown in Fig. 5), the pointed ends of the spikes are positioned below the upper surface 105 of the table 104 next to the apertures 401. By rotation of the shaft 506 the pointed ends 507 may be made to pass through the apertures 401 up above the upper surface of the table 104 and back down through apertures 402. Consequently, in both the retracted position and the forward position, the pointed ends 507 of the spikes 505 are positioned below the upper surface 105 of the support table 104.

One advantage of this is that in either configuration the spikes do not present a danger to a person if they put their hands into the apparatus.

When a sack of material is positioned on the table 104 the forward movement of the spikes 505 will also cause the wall of the sack to be pierced as the pointed ends 507 of the spikes 505 rise up through the apertures 401 and will cause the wall of the sack to be pierced again when the pointed ends 507 of the spikes 505 go down into the apertures 402. In this way, the spikes 505 are able to provide a hook to retain the sack on the support table 104.

In the present example, support table 104 has a pneumatic cylinder located within a cylinder housing 508 fixed to the rear surface 501 of the table 104. A rack and pinion mechanism which is operatively connected to the pneumatic cylinder and the shaft 506 is also located in the housing 508. The pneumatic cylinder is configured to rotate the shaft 506 via the rack and pinion mechanism.

Fig. 4 and 5 also illustrate access ports 403 that are provided in the support table 104 to provide access to the first engagement mechanism. In the present example, the ports 403 are provided with hinged covers which may be lifted as shown in Fig. 4 to provide access.

The apparatus 101 shown in Figs. 1A, 1B and 1C has a transfer mechanism for removing sacks from the support table 104 as will be further described below. In such apparatuses, the transfer mechanism itself may be used to maintain the position of a sack on the support table 104 during a part of the process. Consequently, the sack engagement mechanism 504, located on the support table 104, may not be necessary in such an apparatus.

A partial view of the apparatus 101 showing an alternative support table 104A separated from the first support structure 119 is shown in Fig. 6. The support table 104A differs from support table 104, only in that it does not have a sack engagement mechanism. This Figure provides a clearer illustration of the means by which the support table 104A (and 104) is attached to the first support structure 119.

As mentioned above, the support structure 119 comprises the plates 120 fixed to the rotatable shaft 121. The plates 120 may comprise slots 123 configured to receive the spigots 503 provided on the support table 104A. In the present example, the slots 123 have a dog-leg shape extending from an upper edge of the plates. An indexing plunger 601 is fixed to each of the plates 120 and positioned such that the pin 602 of the indexing plungers may be located in the holes 510 formed in the plates 502 of the support table 104A when the spigots 503 are located in the slots 123. It will therefore be understood that the indexing plungers 601 provide the engagement mechanism for retaining the support table in position on the support structure 119.

The indexing plungers 601 may be of the same type as the indexing plungers 310 located on the blade assembly 108.

A partial view of the transfer mechanism 111 is shown in the front perspective view of Fig. 7 and the rear perspective view of Fig. 8. The transfer mechanism 111 is also shown disassembled in Fig. 9.

The sack retaining structure 112 comprises a plate 701 having an upper surface 151 for supporting a sack during use. The sack retaining structure 112 is provided with sack engagement elements 152, which may be in the form of retractable spikes, similar to spikes 505 of the support table 104 described above. The spikes 152 are shown in their forward position in Figs. 7 and 8 and retracted in Fig. 9. The spikes may have an arcuate shaped portion that extends above the upper surface 151 when the spikes are in their forward position. The spikes 152 each have a pointed free end 801 and an opposite end fixed to a rotatable shaft 802.

The sack retaining structure 112 also comprises a drive mechanism 803 for driving the sack engagement elements 152 into their forward and retracted positions. The drive mechanism 803 is located in a housing 804 mounted on the rear surface 805 of the plate 701. The drive mechanism 803 comprises a pneumatic cylinder (not shown) that is operatively connected to the shaft 802 by a rack and pinion mechanism. Thus, a full stroke of the cylinder in one direction is arranged to cause the spikes 152 into their forward position, and a full stroke in the other direction is arranged to cause the spikes into their retracted position.

The plate 701 is provided with several pairs of slots, such as slots 703 and 704, such that each of the sack engagement elements 152 is arranged to extend through a pair of the slots 703, 704 in the forward position. In the retracted position the sack engagement elements 152 are located below the upper surface 151 of the plate 701.

The sack retaining structure 112 is pivotally mounted on the support arm 113.

In the present embodiment, the support arm 113 comprises two legs 806 which provide pivot means at their ends. The pivot means may be provided by bearings in each of the ends of the legs which retain an axle that is fixed to the plate 701. Alternatively, the pivot means may be provided by an axle that extends between the ends of the legs and that is supported by bearings which are fixed to the plate.

The support arm 113 may be attached to a support structure 115 so that it is detachable. The support structure 115 may comprise two support members 901 fixed to the shaft 177 that forms a part of the drive mechanism 116, as shown in Fig. 9. In this example each of the two support members define a slot 902 extending down from an upper end. The slots 901 are configured to receive bars 903 which extend between the two legs 806 of the support arm 113.

Each of the two support members 901 defines a hole 904 which is positioned to be aligned with the pin 905 of an indexing plunger 906 attached to a respect one of the legs 806 of the support arm 113 when the bars 903 are located within the slots 902 of the support member 901. The indexing plungers 906 may be of the same type as the indexing plungers 310 described above The pin 905 of the indexing plungers 906 may be located in the holes 904 to retain the sack retaining structure 112 and support arm 113 on the support structure 115. However, by withdrawing the pins 905 from the holes 904, the support arm 113 may be lifted to remove the bars 903 from the slots 902 and the sack retaining structure 112 and support arm 113 may be removed from the housing 102 of the apparatus 101. Thus, it will be understood that the indexing plungers 906 provide an arm engagement mechanism 906 which prevents separation of the support arm 113 from the support structure 115 in a first configuration and allows separation of the support arm 113 from the support structure 115 in a second configuration.

Operation of the apparatus 101 is illustrated by Figs. 10 to 17 which show the apparatus 101 in sequential configurations.

A starting position for apparatus 101 is shown in Fig. 10. In operation, sealed sacks 1001 of particulate material are supplied one at a time to apparatus 101 though opening 181. The particulate material may for example comprise a powdered material or a material having larger particle sizes. The sacks may be supplied to the opening 181 by a conveyor 182.

In the starting position of Fig. 10, the blade assembly 108 is fully forward and so the blade 109 is position at the lower end of the support table 104. A first sack 1001A has been slid down the support table 104 and it is being stopped by the blade assembly 109. It may be noted that the sack engagement elements 505 are fully retracted during this initial positioning of the sack.

The blade assembly 108 is supported by the second support structure 126 including the shaft 171 which passes through bearings 172 mounted on arms 175. The arms 175 are mounted to pivot about shaft 177 and the arms 175 are urged into their forward position shown in Fig 10 by a spring means. However, under the weight of the sack 1001A the blade assembly will be pushed back in direction of arrow 1002. The movement of the blade assembly 108 may be restricted to a desired distance by suitable stops. For example the distance may be restricted to between 10 and 30 millimetres.

A position sensor 199 (shown in Fig 1C) may be provided to detect the position of one of the arms 175, and so initiate the next action of the apparatus 101. With the sack 1001A in place on the support table 104, the transfer mechanism 111 is moved from its position shown in Fig. 10 to the position shown in Fig. 11 by the operation of the pneumatic cylinder 153.

The apparatus 101 is shown in Fig. 11 after movement of the transfer mechanism 111 such that the sack retaining structure 112 is positioned above the sack 1001A. The new position of the transfer mechanism 111 may be detected by a sensor, such as a pressure sensor on the low pressure side of the pneumatic cylinder 153.

With the sack retaining structure 112 positioned above the sack 1001A, the pneumatic cylinder located in the housing 804 may then be operated to move the spikes 152 forward so that they pierce the sack 1001A. Alternatively, or in addition, the pneumatic cylinder located in housing 504 of support table 104 may be operated to cause spikes 505 to pierce the sack 1001A. The fully forward positioning of the spikes 152 and/or 505 may be detected by sensing pressure on the low pressure side of the respective pneumatic cylinder.

With the spikes 152 and/or 505 retaining the sack 1001A on the support table 104, the blade assembly 108 may then be retracted by operation of cylinder 174.

The apparatus 101 is shown with the blade assembly 108 in its retracted position in Fig. 12. It will be noted that during this retraction of the blade assembly 108, the arms 175 and the shaft 171 may be urged to return to their forward position under a spring force applied to the arms 175. Therefore the distance between the shaft 171 and the lower end of the sack 1001A is reduced.

The pneumatic cylinder 174 is then operated again to swing the blade assembly 108 forward to cause the edge of the blade 109 to impact upon an end portion of the sack 1004A as illustrated in the cross-sectional perspective view of Fig. 13.

The apparatus 101 is shown in Fig. 14 after the blade assembly 108 has reached its full stroke and cut into the sack 1001A. Consequently, the sack has been cut such that an end portion 1401 of the sack 1001A is attached to the remainder of the sack but only along one side of the sack. When the fully forward position of the blade assembly is detected, the blade assembly 108 is retracted once again by a further operation of cylinder 174. Thus, the now open end of the sack 1001A allows the particulate material 1501 (shown in Fig. 15) within the sack to fall out and through the material outlet 103.

To assist movement of the particulate material from within the sack 1001A the support table 104 may be oscillated by repeated backward and forward strokes of pneumatic cylinder 124 over a period of time or for a number of cycles of the oscillation.

The apparatus 101 is shown in Fig. 15 after retraction of the blade assembly 108 and during oscillation of the support table 104. In Fig. 15 the support table 104 has been tilted downwards and consequently side-pressing elements 161 are extending up above the upper surface 105 of the table 104 and impacting upon side walls of the sack 1004A. This impact assists particulate material located next to the side walls of the sack to be released.

After completion of the oscillations of the support table 104, the transfer mechanism then lifts the sack 1001A from the support table 104. (If spikes 505 are used to support the sack on the table 104 they are retracted before lifting the sack.) At this stage in the process, a large portion of the material originally in the sack has been emptied out and a very small portion of the original material remains in the sack. To remove most of this remaining portion, the sack is moved by the transfer mechanism 111 to an intermediate position in which the sack 1001A is approximately upright with the open end lowermost. This is achieved by operation of pneumatic cylinder 153 until a sensor on the cylinder detects a required position of the piston of the cylinder. The piston of the pneumatic cylinder 153 may then be caused to perform small movements backward and forward to shake the sack while in the inverted position and so remove further material from the sack. The apparatus 101 is shown in Fig. 16 during this process of shaking the sack 1001A.

During the movement of the sack retaining structure 112 by the support arm 113 from the position of Fig. 15 to the position of Fig. 16, the action of the 30 slide support 158 on the slide member 157 causes the sack retaining structure 112 to be rotated about the second axis 156 (which is a line extending into the paper in Figs. 15 and 16) through an angle of about 20 to 40 degrees.

After a period of time of shaking the sack, or after a number of oscillations, the pneumatic cylinder 153 is operated to move the transfer mechanism 111 to a sack separation position. The apparatus 101 is shown with transfer mechanism 111 in the sack separation position in Fig. 17.

During the movement of the sack retaining structure 112 by the support arm 113 from the sack shaking position of Fig. 16 to the sack separation position of Fig. 17, the action of the slide support 158 on the slide member 157 causes the sack retaining structure 112 to be rotated about the second axis 156 though more than 90 degrees (in the present example about 180 degrees). Consequently, the upper surface 151 against which the sack 1001A is held is moved from a position in which it is approximately upright, through a horizontal orientation to the sack separation position. During this movement the sack engagement elements 152 may be retracted such that they are fully retracted by the time the sack separation position is reached. This enables some time to be saved in the process because as soon as the sack separation position is reached the sack 1001A becomes separated from the sack retaining mechanism 112 and the transfer mechanism 111 is ready to begin a new cycle of the apparatus 101.

As shown in Fig. 17, while the transfer mechanism 111 is being moved to the sack separation position, the blade assembly 108 may be moved to its forward position ready to support the next sack 1001B that is to be cut open. Thus, the apparatus 101 is again in its starting configuration as shown in Fig. 10.

An alternative apparatus 101A embodying the present invention is shown in Fig. 19. The apparatus 101A may be the same as apparatus 101 of Fig. 1 but it differs in the arrangement of the sack engagement mechanism 112A. The sack engagement mechanism 112A has two spikes 1901 fixed to each of four shafts such that they pivot about axes which extend horizontally in the present embodiment (into the paper in the view of Fig. 19). The spikes are linked together by a link bar 1902 that may be actuated by a pneumatic cylinder to cause the spikes to rotate through about 90 degrees between forward positions (shown in Fig. 19) and retracted positions. Like the previous arrangement, the spikes are brought to their forward position to engage a sack and a retracted position to disengage the sack.

A second alternative embodiment is shown in Fig. 20. In this embodiment, the apparatus 101B may be the same as apparatus 101 except that it has an alternative transfer mechanism 111A. The transfer mechanism 111A may have a sack engagement mechanism 112 like that of apparatus 101 but it has a different arrangement for moving the sack engagement mechanism. The transfer mechanism 111A has a shaft which supports the sack engagement mechanism 112 via an arm 2002. The shaft is positioned so that it is higher than the sack engagement mechanism 112 in all positions from engagement of the sack on the support table 104, through the intermediate position (shown in Fig. 20), where it may be made to perform a reciprocating action to shake the sack, and to the sack release position where the empty sack is deposited. Like the apparatus 101, the shaft 2001 of the transfer mechanism 111A may be operated by a pneumatic cylinder located on the outside of the rear wall 117 of the housing 102.

A third alternative embodiment is shown in Fig. 21. In this embodiment, the apparatus 101C may be the same as apparatus 101 except that it has an alternative transfer mechanism 111B. The transfer mechanism 111A may have a sack engagement mechanism 112 like that of apparatus 101 but it has different arrangement for moving the sack engagement mechanism. The transfer mechanism 111A may have a sack engagement mechanism 112 like that of apparatus 101 but it has different arrangement for moving the sack engagement mechanism. In this embodiment, the sack engagement mechanism 112 is suspended by an arrn 2101 that has a carriage 2102 arranged to slide along a fixed rail 2103. The carriage 2102 may be moveable along the rail 2103 by a pneumatic cylinder or alternative means such as a chain and motor drive. By this sliding mechanism, the sack engagement mechanism may be moved from the sack engagement position shown in Fig. 21, through an intermediate position, where it may be made to perform a reciprocating action to shake the sack, and to the sack release position where the emptied sack is deposited.

A fourth alternative embodiment is shown in Figs. 22 and 23. In this embodiment, the apparatus 101D may be the same as apparatus 101 except that it has an alternative stopping means for maintaining a correct position of a sack 1001A on the support table 104. In the main embodiment of Fig. 1, the blade assembly 108 is used to provide a stopping means as well as providing the means to cut through the sack. In contrast, the apparatus 101D is provided with a separate stopping mechanism 2201. The stopping mechanism 2201 comprises one or more stopping elements 2202 fixed to a rotatable shaft 2203 mounted below the lower end of the support table 104. In an example, the stopping element may be a plurality of fingers each extending from the shaft 2203. The shaft 2203 may be caused to rotate by a pneumatic cylinder between an up position, where a sack 1001A is held in position (as shown in Fig. 22), and a down position, where a cut flap 2204 of the sack is released to allow particulate material 1501 to fall from the sack (as shown in Fig. 23).

A fifth alternative embodiment is shown in Fig. 24. In this embodiment, the apparatus 101E may be the same as apparatus 101D of Figs. 22 and 23 except that it has an alternative blade mechanism 2401. The blade mechanism 2401 comprises a rotary cutting blade 2402 powered by a motor 2403. The motor 2403 may be a pneumatic motor or an electric motor. The motor 2403 is mounted on two bosses 2404 each supported by a cross-bar 2405 to allow the blade mechanism 2401 to traverse from one side of the apparatus to the other while cutting a similar flap in the sack as achieved by the blade assembly 108 of apparatus 101. Means for causing the traversal of the blade mechanism 2401 may be provided in the form of a pneumatic cylinder or alternatively a chain or belt drive system with an electric motor.

On review of these alternative embodiments, it will be appreciated that the main embodiment of Fig. 1A has the advantage of minimizing the number of actuators, slide rails, etc. that are required to be mounted inside the housing 102 and would therefore be subject to the dust environment. Consequently, the apparatus 101 of Fig. 1A is relatively easy to maintain and clean.

Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed. For example, in the illustrated embodiments, first engagement mechanisms, the second engagement mechanisms and the arm engagement mechanisms 906 have each comprises of indexing plungers. Indexing plungers advantageously provide a quick release mechanism that requires no tools to be used to provide the release, they are easy to handle and remain fixed to one of the components. However, other engagement mechanisms may be used that do not require the use of a tool, such as a spanner or screwdriver to release them. For example, in an alternative embodiment, toggle latches (or toggle catches) are used instead of indexing plungers.

As another example, the drive mechanisms for the motion of the transfer mechanism 111, the motion of the support table 104, the chopping action of the blade assembly 108 and the actuation of the spikes 152 and 505 all comprise pneumatic cylinders. Pneumatic cylinders have the advantage of not requiring an electrical supply and therefore may be safer in apparatus used to empty sacks comprising powdered material that is flammable. Pneumatic cylinders may also have an advantage in that they are driven by a gas and not by a hydraulic fluid as hydraulic cylinders would be. Consequently, they do not provide concerns of contamination of surfaces of the apparatus or material.

However, in alternative embodiments, where these problems are not a concern, the pneumatic cylinders may be replaced by alternative drive mechanisms, such as electric motors or hydraulic cylinders.

Features described in the preceding description may be used in combinations other than the combinations explicitly described.

Although functions have been described with reference to certain features, 10 those functions may be performable by other features whether described or not.

Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

I/we claim:CLAIMS1. Apparatus for opening a sealed sack containing particulate material, the apparatus comprising: a housing having a material outlet; a support table mounted within the housing, the support table having a surface for supporting a sack; a first engagement mechanism configured to retain the support table in position; a blade assembly mounted within the housing, the blade assembly configured to hold a blade for cutting a sack when located on the support table; a second engagement mechanism for retaining the blade assembly in position, wherein at least one of the first engagement mechanism and the second engagement mechanism is configured to be releasable to enable the support table and/or the blade assembly to be removed from the housing.
2. Apparatus according to claim 1, wherein at least one of the first engagement mechanism and the second engagement mechanism is configured to be releasable without a tool.
3. Apparatus according to claim 1 or claim 2, wherein at least one of the first engagement mechanism and the second engagement mechanism comprises a pin arranged to slide between a first position in which the pin engages a hole and a second position in which the pin is retracted from the hole.
4. Apparatus according to claim 2 or claim 3, wherein at least one of the first engagement mechanism and the second engagement mechanism is an indexing plunger or a toggle latch.
5. Apparatus according to any one of claims 1 to 4, wherein the support table is mounted on a first support structure and the first engagement mechanism is configured to retain the support table on the first support structure.
6. Apparatus according to claim 5, wherein the first support structure is configured to tilt the support table to cause a sack to be shaken when located on the support table.
7. Apparatus according to any one of claims 1 to 6, wherein the support table has an upper end and a lower end and the blade is configured to be located at the lower end of the upper surface.7. Apparatus according to any one of claims 1 to 6, further comprising side-pressing elements configured to extend upwards adjacent to side edges of the support table, wherein the support table is configured to tilt independently of the side-pressing elements
8. Apparatus according to claim 7, wherein the side-pressing elements are arranged to extend upwards through slots provided in the support table
9. Apparatus according to claim 8, wherein the side-pressing elements are configured to impact upon side portions of a sack when a sack is located upon the support table and the support table is tilted.
10. Apparatus according to any one of claims 1 to 9, wherein the apparatus further comprises a first sack engagement mechanism configured to retain a sack in position above the support table during tilting of the table.
11. Apparatus according to claim 10, wherein the first sack engagement mechanism comprises at least one spike configured to move upward from an upper surface of the support table to pierce a sack when located on the support table.
12. Apparatus according to claim 11, wherein the spike has an arcuate shape having a pointed end and the pointed end is arranged to move from a retracted position below an upper surface of the support table, upwards above the upper surface of the table and to a fully forward position below the upper surface.
13. Apparatus according to any one of claims 1 to 12, wherein the blade assembly is mounted on a second support structure and the second engagement mechanism is configured to retain the blade assembly on the second support structure.
14. Apparatus according to claim 11, wherein the second support structure is configured to move the blade assembly.
15. Apparatus according to any one of claims 13 to 14, wherein blade has an edge extending within a plane and the second support structure and/or blade 20 assembly comprises a spring means configured allow the blade to be pushed in a direction substantially perpendicular to the plane.
16. Apparatus according to any one of claims 13 to 15, wherein the second support structure is configured to move the blade assembly from a first forward position, in which the blade assembly provides a surface for supporting a sack in position on the support table, to a retracted position and to a second forward position to enable the blade to cut through a sack when located on the support table.
17. Apparatus according to any one of claims 1 to 16, wherein the blade assembly is located adjacent to a lower end of the support table.
18. Apparatus according to any one of claims 1 to 16, wherein the apparatus comprises pneumatic cylinders arranged to generate forces for moving parts of the apparatus.
19. Apparatus according to any one of claims 1 to 18, further comprising a transfer mechanism configured to lift an open ended sack from the support table and move the sack through an intermediate orientation, in which the open end of the sack is beneath an opposite end of the sack, to a separation position where the sack is separated from the transfer mechanism.
20. Apparatus according to claim 19, wherein the transfer mechanism comprises a second sack engagement mechanism configured to provide mechanical engagement with a sack and to release the mechanical engagement before the sack reaches the separation position.
21. Apparatus according to claim 20 or claim 20, wherein the transfer mechanism has a sack retaining structure comprising a support surface configured to support a sack when rotated from an upright position and through a horizontal orientation and the sack engagement mechanism is configured to hold a sack against the support surface.
22. Apparatus according to claim 21, wherein the transfer mechanism comprises a drive mechanism configured to rotate the sack retaining structure from a first upright orientation in which emptying of a sack is completed through the horizontal orientation and to the separation position.
23. Apparatus according to any one of claims 19 to 22, wherein the transfer mechanism comprises: a sack retaining structure comprising support surface for location against a sack and a sack engagement mechanism configured to mechanically engage with a sack located against the support surface; a support arm supporting the sack retaining structure; a drive mechanism supporting the support arm and configured to rotate the support arm about a first axis, wherein the sack retaining structure is pivotally mounted on the support arm to enable the sack retaining structure to rotate about a second axis while the support arm is rotated by the drive mechanism.
24. Apparatus according to claim 23, wherein the transfer mechanism further comprises a rotation mechanism for causing rotation of the sack retaining structure during rotation of the support arm.
25. Apparatus according to claim 23 or claim 24, wherein the second axis is parallel to the first axis.
26. Apparatus according to claim 25, wherein the first axis and the second axis are substantially horizontal.
27. Apparatus according to any one of claims 24 to 26, wherein the rotation mechanism comprises a slide member retained by a slide support, the slide support being anchored at a point, the slide member being configured to slide with respect to the slide support, and the slide member being rigidly attached to the sack retaining structure.
28. Apparatus according to any one of claims 21 to 27, wherein the sack 25 engagement mechanism of the sack retaining structure comprises a moveable arcuate shaped spike.
29. Apparatus for emptying a sack containing particulate material, the apparatus comprising: a support table for supporting a sack during a sack cutting process; and a transfer mechanism configured to lift an open ended sack from the support table and move the sack through an intermediate orientation, in which the open end of the sack is beneath an opposite end of the sack, to a separation position where the sack is separated from the transfer mechanism, wherein the transfer mechanism comprises a sack engagement mechanism configured to provide mechanical engagement with a sack and to release the mechanical engagement before the sack reaches the separation position.
30. Apparatus according to claim 29, wherein the transfer mechanism has a sack retaining structure comprising a support surface configured to support a sack when rotated through a horizontal orientation and the sack engagement mechanism is configured to hold a sack against the support surface
31. Apparatus according to claim 30, wherein the transfer mechanism comprises a drive mechanism configured to rotate the sack retaining structure from a first upright orientation in which emptying of a sack is completed through the horizontal orientation and to the separation position.
32. Apparatus according to claim 31, wherein the transfer mechanism is configured to shake a sack while the sack is in the first upright orientation.
33. Apparatus according to any one of claims 29 to 32, wherein the transfer mechanism comprises: a sack retaining structure comprising support surface for location against a sack and a sack engagement mechanism configured to mechanically engage with a sack located against the support surface; a support arm supporting the sack retaining structure; a drive mechanism supporting the support arm and configured to rotate the support arm about a first axis, wherein the sack retaining structure is pivotally mounted on the support arm to enable the sack retaining structure to rotate about a second axis while the 30 support arm is rotated by the drive mechanism.
34. Apparatus according to claim 33, wherein the transfer mechanism further comprises a rotation mechanism for causing rotation of the sack retaining structure during rotation of the support arm.
35. Apparatus according to claim 34, wherein the second axis is parallel to the first axis.
36. Apparatus according to claim 35, wherein the first axis and the second axis are substantially horizontal. 10
37. Apparatus according to any one of claims 34 to 36, wherein the rotation mechanism comprises a slide member retained by a slide support, the slide support being anchored at a point, the slide member being configured to slide with respect to the slide support, and the slide member being rigidly attached to the sack retaining structure.
38. Apparatus according to any one of claims 34 to 37, wherein the sack engagement mechanism comprises a moveable arcuate shaped spike.
39. Apparatus according to any one of claims 34 to 38, wherein the support arm is releasably attached to a support structure attached to the drive mechanism.
40. Apparatus according to any one of claims 34 to 39, further comprising an 25 arm engagement mechanism which prevents separation of support arm from a support structure in a first configuration and allows separation of the support arm from the support structure in a second configuration.
41. Apparatus according to claim 40, wherein the arm engagement 30 mechanism comprises a pin mounted on one of the support arm and the support structure of the support arm and a hole is located on the other one of the support arm and the support structure, the pin being mounted to slide into the hole to prevent separation of the support arm and the support structure.
42. Apparatus according to claim 41, wherein the pin is a part of an indexing plunger.
43. Apparatus for emptying a sack containing particulate material, the apparatus having a transfer mechanism comprising: a sack retaining structure comprising a support surface for location against a 10 sack and a sack engagement element configured to mechanically engage with a sack located against the support surface; a support arm supporting the sack retaining structure; a drive mechanism supporting the support arm and configured to rotate the support arm about a first axis, wherein the sack retaining structure is pivotally mounted on the support arm to enable the sack retaining structure to rotate about a second axis while the support arm is rotated by the drive mechanism.
44. Apparatus according to claim 43, wherein the transfer mechanism further comprises a rotation mechanism for causing rotation of the sack retaining structure during rotation of the support arm.
45. Apparatus according to claim 44, wherein the second axis is parallel to the first axis.
46. Apparatus according to claim 45, wherein the first axis and the second axis are substantially horizontal.
47. Apparatus according to any one of claims 44 to 46, wherein the rotation mechanism comprises a slide member retained by a slide support, the slide support being anchored at a point, the slide member being configured to slide with respect to the slide support, and the slide member being rigidly attached to the sack retaining structure.
48. Apparatus according to any one of claims 44 to 47 further comprising a support table for supporting a sack during a cutting process, wherein the transfer mechanism is configured to lift an open ended sack from the support table and move the sack through an intermediate orientation, in which the open end of the sack is beneath an opposite end of the sack, to a separation position where the sack is separated from the transfer mechanism.
49. Apparatus according to any one of claims 43 to 48, wherein the transfer mechanism has a sack retaining structure comprising a support surface configured to support a sack when rotated through a horizontal orientation and the sack engagement mechanism is configured to hold a sack against the support surface
50. Apparatus according to any one of claims 43 to 49, wherein the transfer mechanism comprises a drive mechanism configured to rotate the sack retaining structure from a first upright orientation in which emptying of a sack is completed through the horizontal orientation and to the separation position.
51. Apparatus according to any one of claims 43 to 50, wherein the support arm is releasably attached to a support structure attached to the drive mechanism.
52. Apparatus according to any one of claims 43 to 51, further comprising an arm engagement mechanism which prevents separation of support arm from a support structure in a first configuration and allows separation of the support arm from the support structure in a second configuration.
53. Apparatus according to claim 52, wherein the arm engagement mechanism comprises a pin mounted on one of the support arm and the support structure of the support arm and a hole is located on the other one of the support arm and the support structure, the pin being mounted to slide into the hole to prevent separation of the support arm and the support structure.53. Apparatus according to claim 53, wherein the pin is a part of an indexing plunger.
54. A method of disassembling an apparatus for opening a sealed sack containing particulate material, in which the apparatus comprises: a housing having a material outlet; a support table mounted within the housing, the support table having an upper surface for supporting a sack; a first engagement mechanism configured to retain the support table in position; a blade assembly mounted within the housing, the blade assembly configured to hold a blade for cutting a sack when located on the support table; a second engagement mechanism for retaining the blade assembly in position, wherein the method comprises releasing at least one of the first engagement 20 mechanism and the second engagement mechanism to enable the support table and/or the blade assembly to be removed from the housing.
55. A method of emptying a sack containing particulate material, the method comprising: cutting a sack to provide an open ended sack; providing mechanical engagement between the open ended sack and a transfer mechanism; lifting the open ended sack from a support table; moving the open ended sack through an intermediate orientation, in which the 30 open end of the sack is beneath an opposite end of the sack, to a separation position where the sack is separated from the transfer mechanism, wherein the method comprises releasing the mechanical engagement before the sack reaches the separation position.