Device for shredding material, in particular medical waste material

Abstract

A device for shredding material has a shredding rotor, which revolves about an axis of rotation and supports at least one blade, and a first counter-blade which cooperates with the blade of the shredding rotor. A feed plate is provided here, which is mounted to be rotatable about a pivot axis and which is connected to an actuator, in particular to an electric motor, so that, with the aid of the actuator, the feed plate can be brought into a feed position, in which the material to be shredded can lie on a first main surface of the feed plate and can slide along this in the direction of the shredding rotor, and into a first pressing position in which the material to be shredded is likewise pressed with the first main surface of the feed plate against the shredding rotor and shredded between the blade and the first counter-blade.

Claims

1. A device for shredding material, comprising: a) a rotor that revolves about an axis of rotation and supports at least one blade, and b) a first counter-blade, which cooperates with the blade of the rotor; and c) a feed plate rotatable about a pivot axis so that a position of the feed plate about the pivot axis is variable, and wherein d) the pivot axis of the feed plate is arranged with respect to the axis of rotation of the rotor so that the feed plate can be brought into a feed position in which the material to be shredded can lie on a first main surface of the feed plate and can slide along the first main surface in a direction of the rotor, and wherein the feed plate can be brought into a first pressing position, in which the material to be shredded is also pressed with the first main surface of the feed plate against the shredding rotor and is shredded between the blade and the first counter blade, wherein, upon a change in the direction of rotation of the rotor, the feed plate can be brought into a second pressing position in which the material to be shredded is pressed with a second main surface of the feed plate against the rotor and is shredded between the blade and the second counter-blade, wherein the feed plate has a pivoting range of at least 200 about the pivot axis.

2. The device according to claim 1, wherein, in the feed position, the inclination of the first main surface of the feed plate with respect to the horizontal is variable in a range of 5 to 85.

3. The device according to claim 2, wherein the range is 10 to 45.

4. The device according to claim 3, wherein the range is 15 to 25.

5. The device according to claim 1, wherein the axis of rotation of the rotor and the pivot axis of the feed plate define a plane which divides the device into two sub-regions, the first counter-blade being located in a first of the sub-regions and a second counter-blade is located in a second of the sub-regions.

6. The device according to claim 5, wherein the feed plate is mounted at one end so as to be rotatable about the pivot axis.

7. The device according to claim 6, wherein the axis of rotation of the rotor and the pivot axis of the feed plate are spaced from one another so that, upon a change in a direction of rotation of the rotor, the material to be shredded is fed to the second counter-blade.

8. The device according to claim 6, wherein the second counter-blade has a cutting geometry that differs from a cutting geometry of the first counter-blade.

9. The device according to claim 8, wherein the second counter-blade is not arranged along a radius of the rotor.

10. The device according to claim 1, further comprising an actuator provided to rotate the feed plate, and a control that controls the actuator of the feed plate and the shredding rotor so that power input of the rotor does not exceed 3.5 kW.

11. The device according to claim 10, wherein the actuator is an electric motor.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) In the drawing:

(2) FIG. 1 a sectional view of the device for shredding material in a rest position after material has been fed in by an operator;

(3) FIG. 2 a sectional view of the device at a later point in a feed position;

(4) FIG. 3 a sectional view of the device at a later point, in which the feed plate presses the fed-in material against the shredding rotor;

(5) FIG. 4 a sectional view of the device at a later point after a change in the direction of rotation of the shredding rotor;

(6) FIG. 5 a sectional view of the device in a second pressing position;

(7) FIG. 6 a sectional view of the device after a second change in direction of the shredding rotor;

(8) FIG. 7 a sectional view of a second exemplary embodiment of the device in the rest position after material has been fed in;

(9) FIG. 8 a sectional view of the second exemplary embodiment of the device in the feed position.

DETAILED DESCRIPTION OF THE INVENTION

(10) 1. Basic Construction of the Device

(11) In the figures, 10 denotes a device as a whole with which material, in this case medical waste material 12, can be shredded.

(12) Unlike the hitherto conventional method in which medical waste in hospitals is conveyed by cleaning personnel via corridors and lifts to a collecting room in the basement, the device 10 enables it to be shredded on site. The shredded material can then be conveyed via an existing sewage system to the basement, where a wastewater treatment plant removes the material from the waste water and prepares it for final disposal. This considerably reduces the bacterial load on the hospitals.

(13) The device 10 has a housing 14 with a feed opening 16, which can be closed by a lockable flap 17. This enables simple loading from the front or from the side. To close the feed opening 16, it is alternatively possible to provide a displaceable door (not shown specifically) which can be displaced for example between an open and closed position.

(14) Arranged in the interior of the housing 14 are an operator-protection means in the form of a collecting plate 18, a pivotable feed plate 20 and a shredding rotor 22, whereof the axis of rotation 30 is arranged perpendicularly to the plane of projection of the figures. Although the feed opening 16 is shown to the side here with respect to the axis of rotation 30 of the shredding rotor 22, it can also be arranged on a side of the housing 14 which is perpendicular to the shredding rotor 22, depending on the spatial requirements.

(15) The shredding rotor 22 has a substantially cylindrical form and is driven by a drive motor 23, which is only illustrated schematically in FIG. 1.

(16) The shredding rotor 22 supports blades 32 which project in the radial direction. These cooperate with a first counter-blade 24, which is arranged horizontally here, somewhat below the axis of rotation 30, on the circumference of the shredding rotor 22 and therefore substantially radially to the axis of rotation 30 of the shredding rotor 22.

(17) A second counter-blade 26 is offset through approximately 160 relative to the circumference, i.e. it is likewise arranged horizontally here, somewhat above the axis of rotation 30, as a result of which the second counter-blade 26 is not aligned radially to the axis of rotation 30.

(18) The shredding rotor 22 is delimited in a lower circumferential region between the first counter-blade 24 and the second counter-blade 26 by a perforated screen 28, which is at a radial spacing from the shredding rotor 22 and, with this, forms a circumferential gap in which the blade 32 can still pass between the shredding rotor 22 and the perforated screen 28.

(19) The medical waste material 12 can be fed to the shredding rotor 22 in the upper, free circumferential region between the counter-blades 24, 26.

(20) Upon a rotation about the axis of rotation 30, the blades 32 are in contact with the first counter-blade 24 and the second counter-blade 26 and shred the fed-in medical waste material 12 in such a way that this can fall through the perforated screen 28.

(21) The feed plate 20 is arranged above the shredding rotor 22. The feed plate 20 has a first main surface 34 and a second main surface 36 and is mounted such that it is rotatable about a pivot axis 38 extending substantially parallel to the main surfaces 34 and 36. The pivot axis 38 is furthermore arranged substantially parallel to the axis of rotation 30 of the shredding rotor 22.

(22) The feed plate 20 is actively connected in a manner not shown in more detail to an actuator 25 (likewise only shown in FIG. 1) which can be used to vary the angular position of the feed plate 20 about the pivot axis 38. The pivoting range 21 (cf. FIG. 2) of the feed plate 20 covers at least 200 above the shredding rotor 22 here. The actuator 25 can be an electric motor.

(23) Both the drive motor 23 and the actuator 25 are connected to a control means 27 which initiates the different operating modes.

(24) In a further exemplary embodiment, instead of the collecting plate 18, a two-part collecting means 40 is provided, which comprises two collecting flaps 42 as shown in FIGS. 7 and 8.

(25) 2. Mode of Operation of the Device

(26) In the rest position shown in FIG. 1, the collecting plate 18 of the operator-protection means is arranged between the feed opening 16 and the feed plate 20 and is arrested in a substantially horizontal position in which the collecting plate 18 extends substantially to the housing walls and therefore covers the shredding rotor 22. A safety circuit ensures here that the lockable flap 17 on the feed opening 16 of the device 10 can only be opened if the collecting plate 18 is in this covering position. The collecting plate 18 therefore prevents any engagement on the part of the operating personnel and, at the same time, serves as a support for the medical waste material 12 fed through the feed opening 16 of the device 10.

(27) In particular, the collecting plate 18, which is not provided in previously known shredding machines, makes it possible to dispense with providing a circumferential protective wall above the shredding rotor 22. This protective wall normally has a minimum height which is greater than an arm's length of the operator and therefore constitutes a passive operator-protection means. Conventional shredding machines therefore always have to be filled from above and are built high, which means that they can only be used on factory floors. The use of the collecting plate 18 therefore enables their use in normal spaces, such as in hospital rooms.

(28) FIG. 1 shows a first exemplary embodiment of the device 10 in a rest position. Medical waste material 12 is fed to the device through the feed opening 16. This waste material lies on the collecting plate 18 which, in the present exemplary embodiment, is mounted horizontally above the feed plate 20. The collecting plate 18 is brought with a pivotal movement into a vertical storage position, in which it remains during the shredding process. With this, the medical waste material 12 falls onto the first main surface 34 of the feed plate 20, as shown in FIG. 2.

(29) The shredding rotor 22 is then set in rotation (clockwise in FIG. 2). The feed plate 20 is rotated gradually clockwise about the pivot axis 38 out of its horizontal rest position. Provided that the collecting plate 18 has reached its storage position, the medical waste material 12 thereby slides along the first main surface 34 and is fed to the shredding rotor 22 as required.

(30) With this, the medical waste material 12 comes into contact with the blades 32 of the shredding rotor 22, is carried along and chopped into relatively small pieces at the latest at the first counter-blade 24. Once the relatively small pieces have reached a particular minimum size, they can fall through the perforated screen and be disposed of.

(31) The control means 27 monitors the speed and power input of the drive motor 23 and ensures that the inclination of the feed plate 20 is adapted accordingly to prevent too great a power input or a blockage of the shredding rotor 22.

(32) A further metering functionality of the feed plate 20 can also be achieved in that the waste material 12 to be shredded is purposefully trapped between the housing 14 and the feed plate 20, as shown in FIG. 3. This can be especially relevant if the waste material 12 is fed in in sacks or the like.

(33) To this end, starting from the horizontal rest position, the feed plate 20 is pivoted round in such a way that the waste material 12 to be shredded lies on the shredding rotor 22. By pivoting the feed plate further 20, the waste material 12, or the sack in which this is located, is trapped between the feed plate 20 and a housing wall oras in FIG. 3the collecting plate 18.

(34) Through an alternating change in the direction of rotation of the feed plate 20, material which is trapped in this way can be released and trapped again so that it is fed to the shredding rotor 22 as required.

(35) If, as the material 12 is shredded, the weight force alone is not sufficient to achieve efficient shredding, the material 12 can be pressed against the shredding rotor 22. If an increased power input is determined, then the pressure force is reduced or removed.

(36) FIG. 4 shows how the feed plate 20 is used as a pressing means for this purpose.

(37) The control means 27 firstly pivots the feed plate 20 out of the feed position, in which the waste material 12 lies substantially on the first main surface 34, into the first pressing position, in which the feed plate 20 presses substantially from above on the waste material 12 with the first main surface 34 in FIG. 4.

(38) To ensure better contact of the medical waste material 12 with the shredding rotor 22, a pressure force is exerted here by the feed plate 20 on the medical waste material 12, said pressure force being directed substantially perpendicularly to the first main surface 34. The less medical waste material 12 there is between the feed plate 20 and the shredding rotor 22, the greater the force component acting in the radial direction to the shredding rotor. The feed of the medical waste material 12 is further facilitated in that the housing 14 has curved walls in the vicinity of the shredding rotor 22, with these tapering substantially radially with respect to the shredding rotor.

(39) To devise the shredding process more efficiently, the present exemplary embodiment also provides for the shredding rotor 22 to be operated in both directions. This is shown in FIG. 5, in which the shredding rotor 22 is shown running counter-clockwise.

(40) The blades 32 on the shredding rotor 22 are constructed with double cutting edges for this. The pivot axis 38 and the axis of rotation 30 form a plane which divides the housing into two sub-regions. As a result of the change in direction of the shredding rotor 22, the medical waste material 12 arrives from the first sub-region, in which the first counter-blade 24 is located, into the second sub-region, in which the second counter-blade 26 is located.

(41) The shredding rotor 22 in the present exemplary embodiment is arranged eccentrically on the housing 14 so that the plane formed by the pivot axis 38 and the axis of rotation 30 forms an angle with the vertical. This enables an asymmetrical construction of the device 10 with respect to the plane, resulting in the two sub-regions having a geometrically unequal design. This generates a different feed behaviour of the waste material 12 in relation to the respective housing wall and counter-blade 24, 26, which can contribute to a more efficient shredding process.

(42) As a result of the pivot axis 38 of the feed plate 20 and the axis of rotation 30 of the shredding rotor 22 being at a spacing from one another which is greater than the radius of the shredding rotor 22, a passageway is formed between the cylindrical shredding rotor 22 and the pivot axis 38. The medical waste material 12 is then carried along by the shredding rotor 22 and fed to the second counter-blade 26 through the passageway. If the pressure force of the feed plate 20 is removed and the feed plate 20 is pivoted in a counter-clockwise direction and locked in an intermediate position, the feed plate 20 forms a funnel together with the surface of the shredding rotor 22. The medical waste material 12 slides therein along the first main surface 34 of the feed plate 20. Alternatively, the funnel function can however also be achieved by simply removing the pressure force in the first pressing position of the feed plate 20 without this needing to be locked in a defined intermediate position.

(43) As soon as the medical waste material 12 has been transferred into the second sub-region of the device, the feed plate 20 is pivoted in the counter-clockwise direction until it can press with its second main surface 36 against the medical waste material 12, as shown in FIG. 6. The pressure force here acts perpendicularly to the second main surface 36 of the feed plate 20.

(44) The forces acting on the medical waste material 12 can result in an undesired compression of the medical waste material 12 during operation. To loosen this, provision is made in a further step for the direction of rotation of the shredding rotor 22 to change again. The feed plate 20 again cooperates with the surface of the shredding rotor 22 in the manner of a funnel, with the second main surface 36 here serving as a guide element for the medical waste material 12.

(45) The medical waste material 12 is thus transferred from the second sub-region back into the first sub-region of the device 10. To accelerate the shredding process, the feed plate 20 is brought into its first pressing position.

(46) During operation, the change in the direction of rotation can take place a plurality of times, in which case the time at which such a change is introduced can be determined by the control means 27, for example as a result of an increase in the load torque on the drive motor 23 of the shredding rotor 22. Such an increase in the load torque can signify a compression of the medical waste material 12.

(47) 3. Modifications

(48) In a further exemplary embodiment, the operator-protection means is formed by two collecting flaps 40, 42 arranged horizontally in their rest position, as shown in FIGS. 7 and 8. The collecting flaps 40, 42 are pivotably mounted on a common axis 44, which extends substantially parallel to the axis of rotation 30 and the pivot axis 38. In this case, the spacing between the axis 44 and the pivot axis 38 is at least as great as the length of the feed plate 20, so that this latter can be pivoted unhindered between its first pressing position and its second pressing position.

(49) To enable the feed of medical waste material 12, a collecting flap 42 is opened in that it is pivoted in a downward direction. If the collecting flap 42 has been pivoted further and moved out of the pivoting range of the feed plate 20, the medical waste material 12 can be fed to the shredding rotor 22, as shown in FIG. 8.

(50) When, in the next step, the feed plate 20 has reached the first pressing position, the open collecting flap 42 can be pivoted back into its rest position. The collecting means can therefore also fulfil its safety function during operation.

(51) In a further modification of the device 10 according to the invention, it is possible to dispense with a collecting plate 18 or with collecting flaps 40, 42. So that an operator-protection function is still ensured, the open position of the lockable flap 17 can only be achieved in this case when the shredding rotor 22 is not moving. Electrical and/or mechanical monitoring means can be provided for this, which form the operator-protection means in conjunction with the lockable flap 17. In the exemplary embodiments described, material is then fed in during operation preferably when the feed plate 20 is located in its feed position. This enables a metering of the medical waste material 12 to be shredded.

(52) As likewise shown in FIGS. 7 and 8, the device 10 can have an intermediate ceiling 50 above the opening 16. When used for shredding medical waste material 12, nozzles 52 are arranged in this intermediate ceiling and can be used to spray disinfectant and cleaning water into the device 10. This enables the device 10 to be disinfected and rinsed from time to time.

(53) When used to destroy information carriers, a camera 54 which documents the destruction of a particular information carrier can be arranged in the intermediate ceiling 50.

(54) As a further modification, in FIGS. 7 and 8 the feed plate 20 is provided with pressing wedges 56 and 58 on both sides at its end which is remote from the pivot axis 38. The pressing wedges 56 and 58 enable the surface of the feed plate 20 which is active during the pressing procedure to advance more closely to the cylindrical shredding rotor 22.

(55) While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.