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(11) | EP 1 024 084 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Improvements in machines for mounting valve bags |
| (57) Improvements in machines for mounting valve-type sacks (4a, b, c) on filler ports
(51), said machines comprising devices for withdrawing one sack (4a, b, c) at a time
from a pile of horizontally lying sacks, for making at least part of the withdrawn
sack vertical, and for then feeding it to said port, in which said devices comprise
means for withdrawing the sack (4) and making at least part of it vertical, these
means being provided with a sucker arrangement (20) forming part of a penumatically
controlled articulated parallelogram (15, 17, 12, 13) which acts on that end (4a)
of the sack (4) at which the valve (4c) is provided and transfers the withdrawn sack
to a sack support and guide means (22, 25) comprising a stationary component (22)
and a component (25) movable away from and towards said stationary component, said
components (22, 25) comprising rotatable means (24, 28) arranged to cooperate with
motor means (40) to feed the sack towards the filler port (51). |
[0001] This invention relates to improvements in sack mounting machines, ie those machines which mount valve-type sacks on ports through which they are filled for example with pulverulent or grain-like material, such as cement and the like.
[0002] Such machines are known. They generally comprise a point at which valve-type sacks are loaded horizontally into piles, a point at which sacks are withdrawn one by one from the pile and changed from their horizontal position to a vertical position, and a point in which the now vertical sack is moved horizontally with its valve aperture open and is literally propelled over the filler port which at that moment faces and is aligned with the valve. The devices provided at the point at which the sack is withdrawn from the pile and at which the sack is made vertical move sequentially and hence the cycle is relatively slow, it therefore being the main object of this invention to provide improvements which accelerate the withdrawal and vertically positioning cycle. This and further objects which will be more apparent from the detailed description given hereinafter are attained by the improvements of the invention as defined in the accompanying claims.
[0003] The invention will be more apparent from the detailed description of a preferred embodiment thereof given hereinafter by way of nonlimiting example and illustrated on the accompanying drawings, on which:
Figure 1 is a schematic view with parts omitted for clarity, showing a sack mounting machine incorporating the improvements of the invention;
Figure 2 is a side view with parts omitted for clarity, showing the device embodying the improvements of the invention;
Figure 3 is a partial plan view of the sack mounting machine in which the device of the invention can be seen in part;
Figure 4 is a side view with parts omitted for clarity, showing a detail of the device of the invention which in the preceding figures is only partly shown; in this figure the device is shown in its two end-of-travel positions;
Figure 5 is a partial section on the line V-V of Figure 3. With reference to Figure 1, this shows an example of a sack mounting machine incorporating the improvements of the invention, these comprising a device by which piled valve-type sacks are withdrawn one by one by suckers applied to that end at which the relative valve is located, and conveyed by these suckers to rest on guide elements 2, 3 via this end and assume a vertical position (along part of their length). One of said guide elements 3 comprises a rotary wall which is adjacent to the other guide element 2 (which is fixed) and defines with this latter both a support for said end (lying horizontally) of the withdrawn sack and a vertical guide interspace for the vertically orientated part of the sack which follows this end. Motorized means then engage this end to rapidly move the sack towards an at least lowerly open known profiled duct where the valve is opened during the movement of the sack (totally orientated vertically) towards a product loading port which is inserted into the open valve.
[0004] A part of the device of the invention is shown schematically in Figure 1 and comprises the sucker device 1, the fixed element 2 and the movable wall 3 cooperating with the fixed element 2, in addition to other parts and components described in detail hereinafter.
[0005] The valve-type sacks indicated by 4 (see Figure 3 in particular) are arranged piled on a known horizontal support table 5 to which they have been transferred in a known manner by known means which do not form part of the invention. The sacks 4 when flattened comprise in known manner two folded ends 4a, b, of which that indicated by 4a carries a usual valve 4c (indicated by dashed lines). The sucker device 1 is shown in detail in plan view in Figure 3 and in side elevation in its two end positions in Figure 4, and operates on the sack end 4a. It comprises a double-acting pneumatic operating cylinder 6, hinged at 7 to the machine structure and having its rod 8 hinged at 9 between two parallel plates 10 rigid with a lever 11. This lever is pivoted at 12 to a part 13 fixed to the machine structure. In a different position on this structure there is hinged at 13 one end of an adjustable rod 14, the other end of which is hinged at 15 to one end of an angle lever 16, the other end of which is hinged at 17 to the lever 11. The four hinge points 12, 13, 15 and 17 define the vertices of an articulated parallelogram, the sides of which are represented by the lines joining said vertices together in pairs. A suction pipe, in the form of a bent pipe 18, is rigidly joined to the angle lever 16 (at its angle) and to a connecting rod 19 also hinged at the point 17 (see Figure 3) to the lever 11 and parallel to said angle lever. The bent pipe 18 comprises a series of suckers 20 suitably spaced apart and can be connected via a controlled valve, not shown, to a source of vacuum and to atmosphere alternately.
[0006] The suction pipe 18 extends with its suckers 20 projecting towards that side on which the sacks 4 lie in a pile, the described mechanism which operates it being located on one side of this pile (as can be seen from Figures 2 and 3).
[0008] Above the pile of sacks and at a suitable distance therefrom, the machine structure carries (see Figure 5 in particular) a fixed vertical wall 22, which could be adjustable in height, and to the top of which there is connected a horizontal ledge 23 carrying at one end (the right in Figures 2 and 3) a horizontal idle roller 24 which partially emerges from an aperture in said ledge 23. With this wall 22 there is arranged to cooperate (as described hereinafter) a movable wall, indicated overall by 25, provided with a part 26 which during a given period of the operating cycle (Figure 5) lies vertically parallel to the wall 22, and also provided with a right angled ledge 27 also comprising an idle roller 28 which partially emerges.
[0009] The movable wall 25 is connected to a lever 29 pivoted at 30 between supports 31 on the machine structure and on which, at 34, there acts the rod 33 of a double acting pneumatic cylinder 32 pivoted at 35 to the machine structure.
[0010] Two spaced-apart rollers 40, coaxial with each other and with an intermediate driven pulley 41, cooperate with said idle rollers 24, 28 (which as stated slightly emerge from apertures in the relative ledge 23, 27 which carries them). The three components 40, 41 are torsionally connected together and supported at the end of an arm 42 interposed between them. The arm 42 is rotatably supported (at 43) on the shaft of an electric motor 44 driving a pulley 45 which by means of a V transmission belt 46 transmits movement to the wheel and hence to the pair of rollers 40. The rod 48 of a double-acting pneumatic cylinder 47 acts on the arm 42 to raise and lower it from and towards the idle rollers 24, 28 of the driven rollers 40.
[0011] Downstream of the wall 22 there is provided a usual profiled duct 50 the purpose of which is to open the valve 4c of the sack to enable the sack to be mounted over a rotating filler port 51 by propelling the sack the moment these latter become aligned (see Figure 2).
[0012] As can be seen from Figure 2 in particular, with the fixed wall 22 there are associated two parallel horizontal projecting rods 60 which have their end part inclined. These rods guide the end part 4a of the sack, when in the position of Figure 4, and pass through forks 61 fixed to the ledge 27 on the movable wall 25. Said rods are positioned (Figure 2) such as not to interfere with the suckers 20.
[0014] It will be assumed that the suckers 20 are positioned on the end 4a of the highest sack of the pile lying on the support table 5 (Figures 3, 4) and that the sucker carrier pipe 18 is connected to a source of vacuum. By this means the suckers, which are in pneumatic connection with the pipe 18, retain this end 4a of the sack. A central control unit acts on valve means to feed compressed air into the cylinder 6 in such a direction as to move the articulated parallelogram (vertices 12, 13, 15, 17) from the position indicated by full lines (for sack withdrawal) to the position indicated by dashed lines in Figure 4, so dragging the end 4a of the sack 4 by the relative suckers 20, this end remaining horizontal (see Figure 4) while a part of the remainder of the sack assumes a vertical position and a part (that towards the other end 5b) remains horizontal.
[0015] The position shown by dashed lines in Figure 4 is attained when the movable wall 25 has already commenced its movement, under the control of the pneumatic cylinder 32, from the position shown by dashed lines to the left of Figure 5 to the position shown by full lines in the same figure, but not before this movable wall can interfere with the right part of the end 4a of the sack 4 or with the position 18.
[0016] When the movable wall 25 has practically reached the fixed wall 22 (see Figure 5) but without touching it, ie leaving a sufficient distance between them such as not to clamp the underlying part P of the sack 4, the control unit connects the suckers 20 to atmosphere with the result that the sack is abandoned and hence lies in the position shown in Figure 5. The motorized rotating rollers 40 are then lowered against that end 4a of the sack resting on the horizontal ledges 23, 27 on the walls 22, 25, to hence propel the sack 4 towards the filler port 51 by way of the downwardly open profiled duct 50, which opens the valve 4c in order to mount it on the port, as shown by crossed lines. (If another sack is already on the port or if the port is not in position, the rollers 40 are not lowered). As the profiled duct 50 is open downwards longitudinally, the sack becomes positioned vertically in its travel after leaving the pile.
[0017] After the suckers 20 are released from the sack, the articulated parallelogram, which controls the sucker carrier pipe 18, brings this latter into engagement with a new sack of the pile.
[0018] When the sack has been expelled or propelled, the movable wall 25 rises to reach the position shown by dashed lines in Figure 5, and the described cycle is repeated for the new sack.
[0019] The following should be noted:
a) the purpose of the rods 60 is to guide the end 4a of the sack 4 into the required position;
b) any interference between the sucker carrier pipe 18 and the movable wall 25 during possible crossing of the movement between these parts is minimized by the fact that when viewed laterally (Figure 2), the movable wall 25 has the shape indicated by crosses, ie a part B of lesser height h in correspondence with the trajectory of the sucker carrier pipe 18 which terminates at A, hence within the extent of the narrow part B.
1. Improvements in machines for mounting valve-type sacks (4a, b, c) on filler ports
(51), said machines comprising devices for withdrawing one sack (4a, b, c) at a time
from a pile of horizontally lying sacks, for making at least part of the withdrawn
sack vertical, and for then feeding it to said port, characterised in that said devices
comprise means for withdrawing the sack (4) and making at least part of it vertical,
these means being provided with a sucker arrangement (20) forming part of a penumatically
controlled articulated parallelogram (15, 17, 12, 13) which acts on that end (4a)
of the sack (4) at which the valve (4c) is provided and transfers the withdrawn sack
to a sack support and guide means (22, 25) comprising a stationary component (22)
and a component (25) movable away from and towards said stationary component, said
components (22, 25) comprising rotatable means (24, 28) arranged to cooperate with
motor means (40) to feed the sack towards the filler port (51).
2. Improvements as claimed in claim 1, wherein the movable component (25) is rotated
pneumatically from and towards the stationary component (22), the two components (22,
25) defining when in their cooperating position a vertical interspace for passage
of the sack and a horizontal surface (23, 27) for supporting the valved end part (4a)
of the sack (4).
3. Improvements as claimed in the preceding claims, wherein the idle means (40) are rollers
which partially emerge from said horizontal support surfaces (23, 27).
4. Improvements as claimed in the preceding claims, wherein the articulated parallelogram
arrangement (12, 13, 15, 17) is situated to the side of the pile of sacks (4) and
comprises a sucker carrier pipe (18) projecting to extend towards and above the pile
of sacks (4).
5. Improvements as claimed in the preceding claims, wherein the movements of the sucker
carrier pipe (18) and of the movable support and guide component (25) are arranged
such that their mutual crossing takes place without interference, so enabling their
movement to be partly simultaneous to reduce the duration of the operating cycle.
6. Improvements as claimed in the preceding claims, wherein the stationary component
(22) can be adjusted in height.
7. Improvements as claimed in the preceding claims, wherein the stationary component
(22) is provided with projecting rods (60) for guiding the sack, the suckers (20)
being arranged in such a manner as not to interfere with said rods.