WO2014122676A1

WO2014122676A1 - Safety device for the oscillating box feeding door of machines for the treatment of waste

Info

Publication number: WO2014122676A1
Application number: PCT/IT2013/000037
Authority: WO
Inventors: Luciano Salda; Angelo Cappi; Fabrizio NARDINI
Original assignee: C.M.S S.p.A.
Priority date: 2013-02-06
Filing date: 2013-02-06
Publication date: 2014-08-14
Also published as: HK1211557A1; CN104968586A

Abstract

A safety device for the oscillating box door with assisted rotation (5) for feeding machines for the treatment of waste, positioned at the loading mouth (1) of these machines to abut against this with its mouth (108) to enable it to be loaded with waste and arranged to close this mouth (108) progressively upwards and to orient it downwards to discharge the waste into treatment means (2, 3, 104, 4) below, while said loading mouth (1) is closed by the lateral wall of the same door (5), characterized in that this mouth (1) is provided with an upper opening (16) which houses a barrier (17) projecting from this opening with a rounded portion thereof, which is mounted on guide means that enable a movement parallel to itself and tangential to the door (5), to enter and to exit from said opening (16), which is connected to elastic return means (25, 25') that maintain it normally projecting from said opening (16) and cooperating with end of stroke stops (26, 26') and which if pushed inside said opening (16) by an obstacle (H) that projects from the mouth (108) of the door (5) during closing and which is interposed between said barrier and the lower side (305) of the same mouth (108) of the door, operates a sensor (27) connected to means (14) that stop the rotation means (9) of the door (5) and control reversal of the direction of opening rotation of the mouth of this door.

Description

SAFETY DEVICE FOR THE OSCILLATING BOX FEEDING DOOR OF MACHINES FOR THE TREATMENT OF WASTE DESCRIPTION

The invention refers to machines for the collection and compaction of waste produced, for example, by catering activities, provided with at least one lateral mouth, internally communicating with a hopper for loading a compaction press and which is normally closed by an oscillating box door, in the shape of a cradle, which in rest position is oriented with its hollow part facing downwards and on said hopper, so as to discharge into this hopper the waste previously placed therein, while it closes said window with its curved and externally convex wall. In the opposite loading step, the box door is instead oriented with its hollow part facing outwards, abutting against said mouth, to be loaded with the waste to be disposed of and so as to close all connections with the inside of the compacting machine. As prior art closest to the invention, the international patent application WO 2004/067460 by the same applicant is cited, in which said oscillating box door is operated by a gear motor, wherein there are provided end of stroke sensors to detect both the open and the closed position of the door and wherein there is provided, in the upper and middle part of the mouth intercepted by the same door, with downward orientation and with an inclination moving progressively away from the machine, to explore the space in front of the same window, at least one presence sensor, for example of optoelectronic type, which can be entrusted with both cycle and safety functions, the first to control automatic opening of the door in the case of detection of the presence of a tray or a person in the vicinity of the loading mouth of the machine and to subsequently control the opposite closing step of the same door after a predetermined time interval after the presence is no longer detected and the other to interrupt closing of the same door in the case of detection of parts projecting therefrom. Closing of the door normally takes place with upward rotation of the lower side of the same box door, so that this side moves progressively away from the user, for obvious reasons of safety. Said presence sensor is also entrusted with the function of preventing the door from closing in the case of detection of accidental presences outside the same door, such as parts projecting therefrom or a hand attempting to insert an item into the box door at the last minute during the closing step, possibly by inserting the hand into the same door. For this function and also for the aforesaid functions, the prior art means have proved to be somewhat unreliable, both due to the difficulty of ensuring prompt and safe action, also as all this is entrusted to the software of the machine, and due to difficulties of extending the safety control to the entire transverse extension of the loading mouth and of the related intercepting door.

The object of the invention is to overcome these limits of the prior art with a device as claimed in the appended claim 1 and in the subsequent dependent claims, based on the following idea of solution. At the upper side of the loading mouth of the machine, there is placed, parallel, a small barrier mounted on guide means and which is pushed outwards by elastic means and is held resting against end of stroke means. If a thrust is exerted on said barrier towards the inside of the loading mouth of the machine, opposing said elastic means, the movement is detected by a sensor connected to means that promptly reverse the rotation of the box door. To ensure that said barrier reacts with the same sensitivity in any point in which it is pushed and to ensure that its displacement in the operating step takes place without dangerous relative movements in relation to the upper side of the box door, therefore substantially following the displacement of this side, said barrier is mounted on arms that oscillate on an axis parallel and as close as possible to, or coinciding with, the rotation axis of the box door. The oscillation of a cam-shaped end portion of at least one of said arms, placed at a short distance from the oscillation axis of this arm, is promptly detected by a sensor or micro contact which detects the displacement of said barrier, which can take place with a long stroke as the same barrier is placed at a greater distance from the oscillation axis of the related arms than said cam-shaped portion of the arm that cooperates with said micro contact.

Further features of the invention and the advantages deriving therefrom will be more apparent from the following description of a preferred embodiment thereof, illustrated purely by way of non-limiting example, in the two accompanying drawings, wherein:

- Fig. 1 shows the device in perspective and with the box door in semi-closed or semi-open position;

- Fig. 2 shows the safety device with the box door in open position and in a cross-sectional view;

- Fig. 3 shows the box door as in the cross section of Fig. 2 but in closed position;

- Fig. 4 shows the safety device with the box door according to the cross section of Fig. 2, but with the closing step of the same door obstructed;

- Fig. 5 is a flow chart showing operation of the device in question and of the box door with which this device is associated.

In Figs. 1 and 2, the reference letter M indicates the box-shaped body of the compactor, provided in an upper corner area, with both lateral and upper opening, with a loading window or mouth 1 , for example rectangular in shape, which communicates structurally with the hopper 3, which through a lower funnel 103 discharges into the loading mouth 104 of a press 4, for example of screw type, for compaction of waste that is inserted through said loading mouth 1. The bottom opening of the hopper 2 and said mouth 1 are intercepted by a cylindrical box door 5, provided with lateral walls 105 supported rotatably through axial pins 6, by supports 7 fixed to the side panels of the body M, so that the same box door 5 can be controlled to rotate about its own horizontal axis parallel to the horizontal sides of the mouth 1. The reference numeral 205 indicates the curved lateral wall of the box door 5 having an extension such that the inner chamber 8 of the same door communicates with the outside, with a mouth 108 of a width correlated to that of said loading mouth 1 , all so that in the step to load the waste into the treatment machine, the mouth 108 of the door is abutting against the loading mouth 1 , as shown in Fig. 2, while the same box door 5 prevents any direct connection with the internal parts 3, 103, 4, 104. In the step to discharge the waste loaded previously, the box door 5 is in the condition shown in Fig. 3, with the mouth 108 oriented downwards to discharge the same waste, also liquids, into the internal parts 3, 103, 4, 104 which treat the same waste, while the loading mouth 1 of the machine is closed by the lateral surface 205 of the door 5. To pass from the aforesaid open and loading position to the aforesaid closed and discharge position, the door 5 rotates counter clockwise, so that the lower and rounded horizontal edge 305 of its mouth 108 is raised, so that the same mouth 108 closes upwards, moving progressively away from the user, and so as to always prevent any direct connection between the mouth 1 and the internal, lower and operating parts 3, 103, 4, 104 of the machine. Rotation of the door 5 is driven by a small gear motor unit 9 fixed on a support 10 fixed on a side panel of the body M of the machine and connected to the nearby axial pin 6 of the door 5 with direct connection or with interposition of a safety joint (not shown). On the other axial pin 6 of the door there is fitted a cam 1 1 , which in the open and closed positions of the same door 5 cooperates in a known manner with corresponding micro contacts or sensors 12 and 13 fixed on the body M of the machine. In Fig. 2, the reference numeral 14 indicates an electronic board which, through a few hardware components 1 14, controls operation of the gear motor 9 (see below) and to which there are connected both the aforesaid micro contacts 12, 13, and the presence sensor 15, known and, for example, of optoelectronic type, placed on the centre line of the upper side of the mouth 1 and oriented downwards, just above and outside the rotation orbit of the lateral wall 205 of the door 5, without interfering with it, to detect the presence of a user moving towards the machine, normally with a tray and with the waste to be disposed of and which in the case of this detection, through said board 14 controls opening rotation of the door 5, with clockwise rotation thereof and therefore with progressive downward opening of the mouth 108 of the door, to prevent any direct connection between the mouth 1 and the internal parts 3, 103, 4, 104 of the machine.

According to the invention, the mouth 1 is provided with a supplementary opening 16 on the upper horizontal side, in which there is housed a C- or U-shaped cross member 17, so as to be light and also have great bending and torsional strength, an adequate portion of which projects from said opening 16 with the convex and rounded part of its profile, to form an actual safety barrier, as explained in more detail below. The barrier 17 forms the new upper horizontal side of the mouth 1 of the machine and, in the same manner as the previous side, although positioned very close to the door 5, does not interfere with it. The profile barrier 17 has, on the centre line of its outer wall, a window 18 for passage of the radiation of the presence sensor 15 which is fixed inside this barrier by means of a support 19. To facilitate mounting of the sensor 15, the barrier 17 is provided in the intermediate part with an upper opening 20, at which the same barrier has an extension 21 of its lower wall, which terminates with a portion bent upwards, so as to provide a suitable surface on which to place the support 19, and to form a small bumper also on the inner side of the same sensor 15, which is protected towards the outside by being positioned set back and inclined with respect to the window 18.

The barrier is fixed, for example welded, to the bent ends 122 of corresponding flat arms 22, 22' pivoted at the bottom in 23, 23' to the side panels of the body M of the machine, there being anchored to said arms, in 24, 24', on pivot points aligned with each other and parallel to the barrier 17, respective extension springs 25, 25', in turn anchored with the other end to the body M of the compactor, to stress the same arms to abut against end of stroke buffers 26, 26' and to maintain the barrier 17 normally in rest position, with an adequate portion projecting from the upper opening 16 of the mouth.

From the figures it can be seen that one of said arms, for example 22, placed on the side of the gear motor 9, in the portion corresponding to the pivot 23 and which is placed with sufficient angular distance from the anchor point 24 of the spring 25, for example with a distance of approximately 1 15°, has a cam structure 122 that is read by a micro contact 27 fixed laterally to the body M of the machine and connected to the aforesaid electronic board 14.

In Fig. 2 the reference letter A indicates an ideal plane that passes through the rotation axis of the door 5 and on which, or close to which, the point of the lower side of the barrier 17 closest to the door 5 lies, while the reference letter B indicates an ideal plane parallel to the aforesaid plane A and which passes through the pivots 23, 23' of the arms 22, 22'. According to the finding, said ideal plane B can coincide with the plane A or, as shown in the drawings, can be displaced from this and from the mouth 1 , by a distance C so that by exerting a thrust on the barrier 17, opposing the action of the springs 25, 25', the same barrier 17 follows the rotation of the edge 305 of the mouth 108 of the door 5, without being able to move radially towards the same door, but rather moving away from it, for reasons of safety explained below.

Operation of the safety device as described is now described with reference to the flow chart of Fig. 5, wherein:

The reference numeral 28 indicates the rest and standby step of the machine, with the door 5 closed as shown in Fig. 3 and with the presence sensor 15 on. If the presence sensor 15 is activated and if this activation continues for more than a short predetermined time interval, the step 28 is followed by the step 29 of opening the door. The subsequent step 30 detects whether the safety barrier 17 and the presence sensor 15 are free. If they are not free, the door 5 remains open, while if they are free, after a predetermined time interval, the subsequent step 31 to control closing of the door 5 is activated, followed by the step 32, which checks whether the door 5 is closed and whether the related end of stroke micro contact 13 has been activated. If the door 5 closes successfully within a predetermined time interval, the final step 33 of stopping the gear motor 9 and of blocking the door 5 in the closed position takes place, so that it discharges all the waste, also liquid, deposited therein previously. From the step 33, the cycle returns to the initial step 28. If said step 32 detects that the door 5 has not closed within the predetermined time and the related end of stroke micro contact 13 has not been activated, the step 34 is activated to detect whether the safety barrier 17 has been pushed, with switching of the related micro contact 27. If switching of the micro contact 27 is detected, the step 35 takes place, with reversal of the direction of rotation of the gear motor 9 to open the door 5 and the cycle subsequently returns to the beginning of the step 30. It can be understood at this point how operation of the barrier 17 is very safe and easily certifiable, as the signal of the micro contact 27 is sent independently to only a few electromechanical hardware components 114, to which safety is entrusted, and to the board 14 of Fig. 2. If the step 34 detects that the micro contact 27 has not been switched, so that failure to close the door 5 is due to reasons that do not involve the safety barrier 17, the step 36 takes place, to check whether the presence sensor 15 is free. If the sensor 15 is free, so that this fault is not detected by this presence sensor, the cycle returns to the beginning of the step 32 to automatically repeat this step and the subsequent steps. Instead, if the presence sensor 15 is not free and detects the presence of an obstacle in front of it, the step 37 takes place, which, via the software of the machine, controls opening of the door 5. From the step 37 the cycle returns to the beginning of the step 30 to automatically repeat this and the subsequent steps. The reference numeral 38 indicates an optional step to count the activations of the steps 35 and/or 37 so that if these activations are repeated within a short and predetermined time interval, a subsequent step 39 takes place to activate acoustic and/or optical means that warn an operator of the need to take action to restore the correct operating conditions of the machine.

By observing Fig. 4 it can be appreciated how, due to the aforesaid constructional features of the safety device according to the invention, displacement of the safety barrier 17 by any obstacle H present between the same barrier and the side 305 of the door 5 during closing, takes place without related constrictive movements between the two parts 305, 17 and therefore in conditions of total safety for any hand forming said obstacle. It can also be appreciated how the cam-shaped portion 122 of the arm 22 is followed by a portion 222 of the same arm having a radius of curvature with centre on the pivot axis 23, so that even after switching the micro contact 27, without this being subject to further stresses, the barrier 17 can continue to move towards the inside of the opening 16 in overtravel, to further guarantee the safety of the hand H, which can, in total safety, be removed from the door before it closes. Finally, again with reference to Fig. 4, it can be appreciated how the distance between the pivot 23 and the cam 122 is approximately three times less than the advantageous distance existing between the same pivot 23 and the uppermost portion of the barrier 17, which in this way can be displaced with a small thrust for switching the micro contact 27. It is understood that the description refers to a preferred embodiment of the invention, to which numerous variants and constructional modifications can be made, without departing from the basic principle of the invention, as described and illustrated and as claimed below. Naturally, the protection of the invention is extended to all those compaction or waste treatment machines that use oscillating box doors similar to the one considered in this document. In the claims, the reference numerals and letters indicated in brackets are purely indicative and do not limit the scope of protection of these claims.

Claims

1 . A safety device for the oscillating box door of machines for the treatment of waste and machines of this type provided on their body (M) with at least one loading mouth (1 ) open towards the outside and communicating with an internal hopper (3) and with parts (103, 4, 104) below this for the treatment of waste, wherein this communication is intercepted by a box door (5) of a shape correlated to that of said loading mouth (1 ), arranged to rotate on axial pins (6) horizontal and parallel to the transverse direction of said loading mouth (1 ) and which is driven in rotation by motor means (9), of the type that rotate in both directions and provided with means (1 1 , 12, 13) to transmit to an electronic board (14) that controls said motor means (9), signals corresponding to the open and closed end of stroke positions of the door (5), positions in which, during closing, the mouth (108) of the door is oriented downwards and said loading mouth (1 ) is closed by the lateral wall of the same door and in which, during opening, the mouth (108) of the door is open over the loading mouth (1 ) of the machine, while the lateral wall of the same door (5) closes the treatment means (2, 3, 104, 4) below, and wherein the opening and closing movements of the door (5) take place respectively with progressively downward opening and progressively upward closing of the mouth (108), characterized in that at the upper horizontal side of said loading mouth (1 ) and parallel to said side there is arranged a barrier (17) mounted on guide means which enable a movement tangential to the door (5), parallel to itself and moving towards the inside or towards the outside of the machine, which is connected to elastic return means (25, 25') that normally maintain it in an external position and cooperating with end of stroke stops (26, 26') and which if pushed towards the inside during the closing step of the door (5), for example by an obstacle (H) interposed between this barrier and the lower side (305) of the same mouth (108) of the same door (5), activates a micro contact (27), which sends an independent signal to said board (14) and to a few other hardware means (1 14) which are those that stop said motor means (9) that rotate the door (5) to close it and that reverse the direction of rotation to open the mouth (108) of the same door (5), there being provided means so that said active displacement of the barrier (17) takes place without appreciable radial movements of the same barrier (17) towards the door (5).

2. Safety device and machines according to claim 1), wherein said barrier (17) is housed with sufficient clearance in an opening (16) provided on the upper side and on the whole of the transverse extension of the loading mouth (1) of the machine and projects outside this opening (16) with a part thereof with suitably rounded edges and profiles, so that the same barrier (17) forms a new upper and moving side of the loading mouth (1) of the machine, which in the same manner as the previous fixed side, is positioned at a short distance from the perimeter of the door (5), without interfering therewith.

3. Safety device and machines according to claim 2), wherein said barrier (17) is fixed with its ends to the ends (122) of corresponding flat arms (22, 22') constrained at the bottom to the side panels of the body (M) of the machine with the possibility of pivoting on pivots (23, 23') aligned with each other and parallel to the same barrier (17), there being anchored to said arms with one end (24, 24') thereof respective extension springs (25, 25'), in turn anchored with the other end to said body (M) of the compaction machine, and which push the same arms to abut against end of stroke buffers (26, 26'), maintaining said barrier (17) in rest position and with adequate frontward projection from the upper opening (16) of said loading mouth (1).

4. Safety device and machines according to claim 3), wherein the area of the lower side of the barrier (17) closest to the lateral wall (205) of the door (5) is positioned on or a short distance from, an ideal plane (A) which passes through the rotation axis of the same door (5), there being provided that an ideal plane (B) which passes through the pivots (23, 23') of said arms (22, 22') and which is parallel to the preceding ideal plane (A), can coincide with this plane (A) or which is displaced from it and from the loading mouth (1 ) by a distance (C), so that by exerting a thrust on said barrier (17) to move it inside the opening (16) in which it is housed, opposing the action of said springs (25, 25'), the same barrier (17) tangentially follows the rotation of the lower edge (305) of the mouth (108) of the door (5), without any radial movement thereof towards the same door (5).

5. Safety device and machines according to claim 3), wherein one of said arms (22, 22'), in the portion corresponding to the related pivot (23) and which is placed with sufficient angular distance from the end (24) for anchoring the related return spring (25) to said arm, has a cam structure (122) that is read by a micro contact (27) fixed laterally to the body (M) of the machine and connected to said electronic board

(14) , it being provided that the cam-shaped portion (122) of the arm (22) is followed by a portion (222) of the same arm having a radius of curvature with centre on the pivot axis (23) of the same arm (22), so that even after switching said micro contact (27), without this being subjected to further stresses, the barrier (17) can continue to move towards the inside of the machine in overtravel, to further guarantee the safety of any obstacle H projecting from the mouth (108) of the door (5) and which can, in total safety, be removed from the door before it closes.

6. Safety device and machines according to claim 5), wherein the distance between the pivot (23) of the arm (22) and the related cam (122) is less than the distance between the same pivot (23) and the uppermost portion of the barrier (17) integral with said arm (22), so that the same barrier (17) is mounted on an advantageous system of arms (22, 22') and can be displaced with a small thrust for switching the related safety micro contact (27).

7. Safety device and machines according to one or more of the preceding claims, wherein said barrier (17) has a C- or U-shaped profile so as to be relatively light and also have great bending and torsional strength, said barrier being provided on the centre line of its outward facing wall with a window (18) for the passage of the radiation of a presence sensor (15) which is fixed inside this barrier by means of a support (19), it being provided that to facilitate mounting of said sensor (15), the same barrier (17) is provided in the intermediate part with an upper opening (20), at which the same barrier has an extension (21) of its lower wall, which terminates with a portion bent upwards, so as to provide a suitable surface on which to place said support (19), and to form a small bumper also on the inner side of the same sensor

(15) , which is protected towards the outside by being positioned suitably set back and inclined with respect to said window (18).

8. Safety device and machines according to one or more of the preceding claims, characterized by comprising means to enable it to operate with the sequence of the following operating steps: the waste treatment machine is normally in a standby step (28), with the door (5) closed and with the presence sensor (15) on and when this sensor (15) detects a presence in its range of action and this presence continues for more than a short predetermined time interval, said standby step (28) is followed by a step (29) of opening the door (5) and a subsequent step (30) to detect whether the safety barrier (17) and the presence sensor (15) are free, it being provided that, if they are not free the door (5) remains open while, if they are free, after a predetermined time interval, a subsequent step (31 ) is activated to control closing of the door (5), followed by a step (32) which checks whether said door (5) is closed and whether the related end of stroke micro contact (13) has been activated and, if the door (5) has closed successfully within a predetermined time interval, the final step (33) of stopping the gear motor (9) and of blocking the door (5) takes place, and from this step (33) the cycle returns to the initial standby step (28), there also being provided means which, if said second last step (32) detects that the door (5) has not closed within the predetermined time and the related end of stroke micro contact (13) has not been activated, activate a step (34) to detect whether the safety barrier (17) has been pushed, with switching the related micro contact (27), it being provided that if switching of this micro contact (27) is detected, a step (35) takes place, which, via hardware (114) reverses the direction of rotation of the gear motor (9) to open the door (5) and the cycle subsequently returns to the beginning of said step (30) to detect whether the safety barrier (17) and the presence sensor (15) are free to automatically repeat the subsequent steps.

9. Safety device and machines according to claim 8), characterized by comprising means which, if in the second last step (34) it is detected that the micro contact (27) of the barrier (17) has not been switched, so that failure to close the door (5) is due to reasons that do not involve the same safety barrier (17), a step (36) takes place to check whether the presence sensor (15) is free, i.e. if it does not detect or detects presences, in the first case the cycle returning to said intermediate step (32) to check closing of the door (5) again and automatically repeat the subsequent steps, while instead, if the presence sensor (15) detects the presence of an obstacle in front of it, a step (37) takes place which, via the software of the machine, controls the opening of the door (5), it being provided that from this step (37) the cycle then returns to the beginning of said intermediate step (30) to detect whether the safety barrier (17) and the presence sensor (15) are free to automatically repeat the subsequent steps.

10. Safety device and machine according to claim 9), characterized by comprising means for performing a step (38) of counting the activations of said last steps (35 and/or 37) to re-open the door (5), so that if these activations are repeated several times within a short and predetermined time interval, a subsequent step (39) takes place to activate acoustic and/or optical means to warn an operator of the need to take action to restore the correct operating conditions of the machine.