Dosing device for potting soil

Abstract: Dosing device (1) for dosed discharge of a bulk material mass from a storage container which comprises at least two parallel opposite walls (3,4) and wherein an infeed opening and outfeed opening are respectively provided between the corresponding outer ends of these walls for receiving this mass between these walls and the infeed and outfeed openings, comprising a carriage (2) displaceable along the upper side of said walls, on which carriage at least one gripper arm (8) is suspended pivotally at one end round a pivot shaft extending transversely of the walls, which gripper arm is provided at the other end with a gripper element (10), wherein the gripper element is displaceable controllably or freely as desired in vertical direction, and the carriage is displaceable over a distance and the gripper arm has a length such that the gripper element is displaceable over the entire length of the space bounded by the walls.

Description: The invention relates to a dosing device for dosed discharge of a bulk material mass, for instance potting soil, from a storage container which comprises at least two parallel opposite walls and wherein an infeed opening and outfeed opening are respectively provided between the corresponding outer ends of these walls for receiving this mass between these walls and the infeed and outfeed openings. Such a dosing device is known wherein the container is formed by the walls and a movable bottom bounded by the walls and comprising a conveyor belt. The container is disposed for instance such that the conveyor belt ends above a second conveyor belt for further transport of the bulk material mass or, when the dosing device is used for potting soil, above a per se known potting machine in which pots are filled with potting soil, into which is then placed a plant for cultivation. Each time soil is dosed from the known dosing device the whole soil supply in the storage container is necessarily displaced in the direction from the infeed opening to the outfeed opening, as a result of which the conveyor belt and the drive thereof must have a heavy construction respectively a high capacity, which in turn results in high initial and operating costs. Another drawback of the known dosing device is that the dosing accuracy is low, because the quantity of soil dispensed at the end of the conveyor belt is determined both by the displacement of the conveyor belt and the height of the supply on the conveyor belt, and this height, determined by the manner of filling of the storage container, is quite random. Furthermore a closing device according to the preamble of claim 1 is known from GB-A-2 241 934. The object of the invention is to provide a dosing device which is simple to construct and to use and of which the purchase and operating costs are relatively low and with which a determined quantity of a bulk material mass for dosing can be discharged in reliable manner, wherein the dosing accuracy is not dependent on the height of the supply of this mass. These objectives are achieved, and other advantages obtained, with a dosing device of the type stated in the preamble, which is characterized according to the invention by a carriage, on which carriage at least one gripper arm is suspended pivotally at one end round a pivot shaft extending transversely of the walls, which gripper arm is provided at the other end with a gripper element, wherein the gripper element is displaceable controllably or freely as desired in vertical direction, and the carriage is displaceable over a distance and the gripper arm has a length such that the gripper element is displaceable over the entire length of the space bounded by the walls. In an embodiment the at least one gripper arm has a fixed length which is greater at any position of the carriage than the distance from the pivot shaft to the bottom surface between the walls. In another embodiment the at least one gripper arm is telescopic, wherein the maximum length of the gripper arm is at least equal to the maximum distance from the pivot shaft to the bottom surface between the walls. Filling of a dosing device according to the invention with a bulk material mass takes place in simple manner in a situation wherein the gripper arm is held in its highest position. The dosed discharge of the bulk material mass takes place by successively performing the steps of (1) displacing the carriage to the infeed opening of the storage container, wherein the gripper arm is held in its highest position, (2) lowering the gripper arm in controlled manner until the gripper element rests freely on the bottom surface or the bulk material mass present thereon, (3) displacing the carriage to the outfeed opening of the storage container, wherein the gripper element is freely displaceable in vertical direction and in this situation pushes ahead of itself a quantity of bulk material mass from the top of the supply, which quantity, in the case of sufficient supply, is determined practically solely by the form and dimensions of the gripper element, (4) raising the gripper element as soon as it has reached the outfeed opening and the pushed forward quantity of bulk material mass has been pressed out of the outfeed opening by the gripper element, and (5) repeatedly performing step (1). In a practical embodiment the carriage is displaceable using drive means over parallel guides extending horizontally along the walls. In this embodiment an electric motor is for instance placed on the carriage for displacing the carriage and lowering or raising the gripper element as required. In a simple embodiment of a device according to the invention the carriage is displaceable under the influence of the force of gravity in the direction from the outfeed opening to the infeed opening over parallel guides inclining upward along the walls in the direction from the infeed to the outfeed opening, and drive means are provided for displacing the carriage in the direction from the infeed to the outfeed opening. In this embodiment the drive means for the carriage are formed for instance by a first winch placed at the highest point of the guides and the carriage comprises a second winch for lowering or raising the gripper element as required. In a very advantageous embodiment of a dosing device according to the invention the bottom surface between the walls has on at least a part thereof bounded by the outfeed opening an upward sloping incline in the direction from the infeed opening to the outfeed opening. In a further embodiment the incline can be adjusted using adjusting means such that the bottom surface at the location of the outfeed opening ends for instance just above a potting machine or a conveyor belt, so that the soil pushed along by the gripper element is deposited in this potting machine respectively onto this conveyor belt. The gripper element in a device according to the invention comprises for instance a slide which is placed at a determined angle relative to the at least one gripper arm, which angle is preferably adjustable using adjusting means. In order to prevent the usually moist potting soil compacting or caking onto the bottom surface, the slide in yet another embodiment comprises a row of tooth-shaped protrusions directed toward the bottom surface. The invention will now be elucidated hereinbelow on the basis of an embodiment with reference to the annexed drawings. In the drawings Fig. 1 shows schematically in broken-away perspective view an embodiment of a potting soil dosing device according to the invention in a first situation, Fig. 2 shows the dosing device of fig. 1 in a second situation which follows the first situation, Fig. 3 shows the dosing device of fig. 1 in a third situation following on from the second situation, and Fig. 4 shows the dosing device of fig. 1 in a fourth situation following on from the third situation. Figure 1 is a highly simplified view of a dosing device 1 for dosed discharging of potting soil 2 from a storage container substantially consisting of two parallel opposite walls 3, 4 and wherein between the corresponding ends 5, 6 of these walls 3, 4 an infeed opening and outfeed opening are respectively formed for infeed and outfeed of potting soil 2. Displaceable along the upper side of said walls 3, 4 is a carriage 7 on one end of which two gripper arms 8 are suspended round a pivot shaft 9, which gripper arms 8 are provided on the other end with a gripper element 10, wherein at any position of carriage 7 the fixed length of gripper arms 8 is greater than the distance from pivot shaft 9 to bottom surface 11 between the walls 3, 4. An electric motor 12 is placed on carriage 7 for displacing of carriage 7 provided with wheels 15, 16 over a pair of parallel horizontal guides 13, 14 and for lowering or raising gripper element 10 as required, which element is displaceable over the entire length of the space bounded by walls 3, 4. A part 17 of bottom surface 11 bounded by the outfeed opening has an incline sloping upward in the direction from the infeed to the outfeed opening and adjustable by means of adjusting means (not shown) and ending above the infeed side of a potting machine 18 and above a conveyor belt 19, which likewise ends above the infeed side of said potting machine 18. A slide 20 is placed on gripper element 10 at a determined angle relative to gripper arms 8, which angle can be varied subject to the desired dose and the substance of the potting soil mass. The figure shows a situation in which carriage 8 is fully retracted to the outfeed side and gripper 8, 10, 20 lies in its highest position, while a quantity of potting soil 2 lies on bottom surface 11 close to the infeed opening. Fig. 2 shows dosing device 1 of fig. 1 in a following situation, wherein carriage 7 has been moved wholly to the infeed opening and gripper element 10 rests freely on and behind the potting soil mass 2 such that slide 20 can push a determined dose ahead of itself. Fig. 3 shows dosing device 1 of fig. 1 in a further advanced position, wherein carriage 7 has been moved halfway towards the outfeed opening from the infeed opening and has pulled gripper element 10 along behind it, wherein slide 20 has pushed along a determined dose ahead of itself. Fig. 4 shows dosing device 1 of fig. 1 in even further advanced position, wherein carriage 7 has been moved wholly to the outfeed opening and gripper element 10, which rests freely on the end of the inclining bottom part, has deposited the dose of potting soil pushed along by slide 20 over the edge of inclining bottom part 17 onto the infeed side of the potting machine 18 and onto conveyor belt 19. It is emphasized that the above described embodiment serves to elucidate the invention and not to limit it. Within the scope of the inventive concept it is possible for instance to incorporate the dosing device as a modular system in a transport container or in a trailer provided with wheels, so that the device can be used at any desired location. The bottom surface between the opposite walls is preferably formed by a flat concrete plate provided with an inclining part rising toward the outfeed opening, but can also be provided with a part sloping downward toward the outfeed opening, or can be formed by the ground surface on which the walls are disposed. The opposite walls are preferably so far apart that a truck can be driven into the infeed opening therebetween. The inner walls of a shed, the walls of a container or truck or per se known sheet pile elements can be used as walls, wherein the guides for the carriage can be arranged on, above or along the mutually facing inner sides of the walls. Flat rails or round bar material can be used as guides for the carriage, or one or both guides can be made in the form of a gear rack, wherein the corresponding wheels are embodied as toothed wheels. It is further possible to suspend the carriage from a monorail system, so that only one guide can suffice. In a simple device the control of the carriage and of the gripper can be manual, wherein for instance the drives are provided by winches, while in devices wherein the carriage is provided with an electric motor the control can be fully automated.

Claims: Dosing device (1) for dosed discharge of a bulk material mass (2), for instance potting soil, from a storage container which comprises at least two parallel opposite walls (3, 4) and wherein an infeed opening and outfeed opening are respectively provided between the corresponding outer ends (5, 6) of these walls for receiving this mass (2) between these walls and the infeed and outfeed openings, wherein a carriage (7) is displaceable along the upper side of said walls (3, 4), characterized in that on the carriage at least one gripper arm (8) is suspended pivotally at one end round a pivot shaft (9) extending transversely of the walls (3, 4), which gripper arm (8) is provided at the other end with a gripper element (10), wherein the gripper element (10) is displaceable controllably or freely as desired in vertical direction, and the carriage (7) is displaceable over a distance and the gripper arm (8) has a length such that the gripper element (10) is displaceable over the entire length of the space bounded by the walls (3, 4). Device (1) as claimed in claim 1, characterized in that the at least one gripper arm (8) has a fixed length which is greater at any position of the carriage (7) than the distance from the pivot shaft (9) to the bottom surface (11) between the walls (3, 4). Device as claimed in claim 1, characterized in that the at least one gripper arm is telescopic, wherein the maximum length of the gripper arm is at least equal to the maximum distance from the pivot shaft to the bottom surface between the walls. Device as claimed in any of the claims 1-3, characterized in that the carriage (7) is displaceable using drive means (12) over parallel guides (13, 14) extending horizontally along the walls (3, 4). Device (1) as claimed in claim 4, characterized in that an electric motor (12) is placed on the carriage (7) for displacing the carriage (7) and lowering or raising the gripper element (10) as required. Device as claimed in claim 1 or 2, characterized in that the carriage is displaceable under the influence of the force of gravity in the direction from the outfeed opening to the infeed opening over parallel guides inclining upward along the walls in the direction from the infeed to the outfeed opening, and drive means are provided for displacing the carriage in the direction from the infeed to the outfeed opening. Device as claimed in claim 6, characterized in that the drive means for the carriage are formed by a first winch placed at the highest point of the guides and the carriage comprises a second winch for lowering or raising the gripper element as required. Device (1) as claimed in any of the foregoing claims, characterized in that the bottom surface between the walls has on at least a part (17) thereof bounded by the outfeed opening an upward sloping incline in the direction from the infeed opening to the outfeed opening. Device (1) as claimed in claim 8, characterized in that the incline is adjustable using adjusting means. Device (1) as claimed in any of the foregoing claims, characterized in that the gripper element (10) comprises a slide (20) which is placed at a determined angle relative to the at least one gripper arm (8). Device (1) as claimed in claim 10, characterized in that the determined angle is adjustable using adjusting means. Device (1) as claimed in claim 10 or 11, characterized in that the slide comprises a row of tooth-shaped protrusions directed toward the bottom surface.

Inventors: VAN, VAN KEMPEN, ANTONIUS GERARDUS
Applicants: KEMPEN ANTONIUS GERARDUS VAN, VAN KEMPEN, ANTONIUS GERARDUS
Application year: 1998
Main classification: A01G9
IPC codes: A01G9