MXPA99008053A - All-purpose conduit for conveying harmful fumes or gases away from a work station - Google Patents

Abstract

The conduit (5) includes a rotary fitting (11), and two segments (18, 19) elbow-connected to each other and each having an articulated mechanism (23, 24) including a pair of U-section bars (26, 27) connected to each other in the form of an articulated parallelogram by means of two articulated elements (37, 44;44, 51). A spiral compression spring (35, 36) is housed between each pair of bars (26, 27), and is compressed between a disk (55), integral with one of the bars (26, 27), and a flange (64) sliding along a threaded rod (62). The flange (64) is locked on the rod (62) by means of a nut (67), and the rod (62) is connected to a lever member (69) pivoting on one of the articulated elements (37, 44) so as to adjust the action of the spring (35, 36) as a function of the angular position of the relative segment (18, 19) with respect to the articulated element (37, 44).

Description

CONDUCT OF GENERAL USE TO TRANSPORT THE FUMES OR GASES HARMFUL OF A WORKING STATION FIELD OF THE INVENTION The present invention relates to a conduit of general use for transporting the fumes or harmful gases of a work station. More specifically, the present invention relates to a conduit comprising a connection between a vacuum cleaner and a flexible conduit portion, and wherein the connection rotates about its own axis to allow both radial and angular movement of the conveyor element around it. axis.

BACKGROUND OF THE INVENTION Various conduits of the above type are known. In one, a long flexible conduit is provided between the connection and the conveyor element and houses an articulated mechanism that allows the conduit s to substantially bend in the central line and the mechanism comprises a pair of spiral tension springs also housed in the inside the duct and acting between an articulated plate and two opposite points of the mechanism. An important disadvantage of this type of duct is the rapid deterioration caused by the particles of the fumes deposited in the mechanism and in the springs. Another known conduit has two rigid conduit segments, one of which is connected to the connection at the top by means of a first portion of flexible conduit; a second portion of flexible conduit is fitted between the two rigid segments; the articulated connections between the connection and the rigid segment and between the two rigid segments are constituted by means of pairs of articulated forks; high friction discs are inserted between the arms of the forks; Spiral tension springs are inserted between the connection and an intermediate point on the outside of the duct. An important disadvantage of this type of conduit is the considerable force required to overcome the friction of the discs and move the conveyor element. In addition, the springs, being external, are subject to the incrustation and are released when accidentally hit and, being a safety risk, both the springs and the forks must be protected, thus increasing the cost of the conduit.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a reliable and very direct conduit for transporting harmful fumes or gases, designed to overcome the aforementioned disadvantages normally associated with known conduits. In accordance with the present invention, there is provided a general purpose conduit for transporting harmful fumes or gases from a work station and comprising a connection between a vacuum cleaner and a flexible conduit portion, the connection rotates about its own axis; at least one segment of conduit is connected to the flexible conduit portion; an articulated mechanism for varying the angular position of the conduit segment with respect to the connection; and compensating spring means; characterized in that the mechanism comprises a pair of bars connected to one another in the form of an articulated parallelogram and forming a substantially closed channel; the spring means comprises a spiral compression spring, housed in the channel and connected so as to operate in a varied manner in accordance with the angular position of the conduit segment with respect to the connection.

BRIEF DESCRIPTION OF THE DRAWINGS By way of example, two preferred and non-limiting embodiments of the present invention will be described, with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of a first embodiment of a conduit for use General for transporting harmful fumes or gases from an industrial work station, in accordance with the present invention; Figure 2 shows a schematic vertical view, partly in section of the articulated mechanisms of the conduit of Figure 1; Figure 3 shows a vertical section on a larger scale of a portion of Figure 2; Figure 4 shows a section along line IV-IV of Figure 3; Figure 5 shows a section on a larger scale along the line V-V in Figure 2, in a different operating position; Figure 6 shows a partial view on a larger scale along the line VI-VI in Figure 2; Figure 7 shows a perspective view of a further embodiment of a conduit for general use for transporting harmful fumes or gases, in accordance with the present invention.

BEST WAY TO CARRY OUT THE INVENTION Number 5 of Figure 1 indicates, as a whole, 2/68 a conduit for transporting harmful fumes or gases from an industrial or non-industrial work station. The duct 5 is preferably circular in section and is connected to a vacuum cleaner 6 activated by an electric motor with a fume carrying element acting as a suction hood 7. The vacuum cleaner 6 is normally fitted below a fixed or mounted support 8. wheelbarrow, for example, horizontal support almost level with the work station from which fumes will be transported; and the bell 7 is movable to place it directly on the region where the fumes are produced, it is usually made of plastic material, it has a truncated cone shape with the axis inclined with respect to the two parallel ends and comprises a handle 9. The duct 5 comprises an annular connection 11 between the sucker 6 and a known flexible portion 12 of the bellows type of the duct 5; the connection 11 is connected to the vacuum cleaner 6 by means of a rolling bearing (not shown), so that it rotates around its own axis 14; and another flexible portion 16 of bellows type of the conduit 5 is rigidly fitted to the upper edge of the bell 7. The flexible portions 12 and 16 are respectively connected to the ends of two segments 18 and 19 preferably straight and therefore , cylindrical of duct 5; the segments 18 and 19 are connected to each other with an elbow by means of an additional flexible portion 21 of the bellows type; the segment between the segment 19 and the bell 7 is fitted with a known articulated bracket 22 for bending the flexible portion 16; a first articulated mechanism 23 is provided to adjust the angular position of the segment 18 with respect to the connection 11; and, similarly, a second articulated mechanism 24 for adjusting the angular position of segment 19 with respect to segment 18 is provided. Segments 18 and 19 may be either rigid or flexible; the mechanisms 23 and 24 can be located inside or outside the conduit 5; and, in the embodiment of Figures 1 and 2, the segments 18 and 19 have a cylindrical wall 20 rigid. According to the invention, each mechanism 23 and 24 comprises a pair of bars 26 and 27 (Figure 2), connected together in the form of an articulated parallelogram; the bar 26 has a U-shaped section with a spine 28 (see also Figure 4) and two parallel wings 29; and, the spine 28 of the bar 26 is fitted on the outside of the relative segment 18 and 19 by means of at least two fastening elements or brackets 31. More specifically, the spine 28 can be screwed, riveted or welded to the brackets 31, which are in turn screwed, riveted or welded along the lower generating line of the vertical diametrical plane of the relative segment 18, 19. The bar 27 is also shaped like a ü with a spine 32 and two parallel wings 33 closer than the wings 29; the bar 27 is positioned opposite the bar 26, where the wings 33 are inserted between the wings 29 to form a substantially closed channel 34 and the two channels 34 of the mechanisms 23 and 24 house the respective compression springs 35 (FIG. 3) and 36 (Figure 5) described in detail below. Each mechanism 23 and 24 comprises two articulated elements for the bars 26 and 27 which are connected in parallelogram. One of the two articulated elements of the mechanism 23 (Figures 1 and 3) comprises a U-shaped section 37 fixed by a bracket 38 to the connection 11 and having two wings 39 (see also Figure 4), separated to fit between the wings 29 of the bar 26 and the wings 33 of the bar 27. A bolt 40 is fitted near the ends of the wings 29 of the bar 26, adjacent to the section 37, and extends through two spacer rollers 41 and two holes formed in the wings 39 of the section 37, so that the bar 26 is connected in an articulated manner to the section 37. Similarly, an additional bolt 42 is fitted to the flanges 39 of the section 37 and extends through two additional spacer shells 43 and two holes formed in the ends of the flanges 33 of the bar 27, which is also connected therefore in articulated form with the section 37. The second articulated member of the mechanism 23 comprises an additional U-shaped section 44 (Figure 2) having two wings 45 spaced the same distance as the wings of the section 37 and which, in the same as the bolts 40 and 42, are connected in an articulated manner, by means of two additional bolts 46 and 47, to the other ends of the wings 29 and 33 of the bars 26 and 27. The bolts 40 and 42 are located so that the respective axes remain in a plane P (Figure 3) inclined, in the example shown, at an angle of 45 ° with respect to the axis 14 of the connection 11; and the bolts 46 and 47 are obviously in a plane parallel to the plane P. One of the two articulated elements of the mechanism 24 (Figure 2) comprises the same section 44, whose wings 45 are connected in an articulated manner to the ends of the wings 29 and 33 of the relative bars 26 and 27 by means of two additional bolts 48 and 49, so that the section 44 defines an articulated element common to both mechanisms 23 and 24, which thus present a 52/68 self-support characteristic. The bolts 46-49 are arranged in the form of a trapezoid with the long side at the top. The second articulated member of the mechanism 24 comprises a third U-shaped section 51, which, by means of two bolts 52 and 53, is connected only in an articulated manner to the other ends of the wings 29 and 33 of the bars 26 and 27. At each end, the wings 29 of the bars 26 of the two mechanisms 23 and 24 comprise a cavity 50 which allows the rods 26 to rotate with respect to the sections 37, 44, 51 without interfering with the ends of the respective bolts 42, 47, 49, 53. The edges of the wings 33 of the bar 27 of each mechanism 23 and 24 are welded to a respective metal tube 54 (Figures 2-5) into which the respective spring 35, 36 is inserted; and, at a certain distance from the end of the bar 27 adjacent to the section 37 (mechanism 23) and section 44 (mechanism 24), the tube 54 is fitted inside with a stop to stop the spring 35, 36 and. which comprises a disk 55 having a hole and which is secured to the tube 54 by means of a radial bolt or bolt 56. A member comprising a piston 57 slides inside the tube portion 54 adjacent to the section 37, 44, and comprises two annular grooves accommodating two piston rings 58 made of low friction material to smoothly guide the piston 57 along the tube 54. Each piston 57 comprises a threaded hole 59 engaged by the threaded end 61 of a rod 62 around from which the respective springs 35 and 36 are wound. The other end 63 of the rod 62 is adapted with a second stop to stop the respective spring 35, 36 and which comprises a flange 64 of a sleeve 66 that slides freely at length of the rod 62. The end 63 is also threaded and is engaged by a nut 67 to secure or immobilize the flange 64 in opposition to the action of the spring 35, 36. As shown in Figs. 2 and 5, the rod 62 may be advantageously threaded along its entire length to integrate the two ends 61 and 63. Each nut 67 is screwed in an adjustable manner to the end 63 of the rod 62 to adjust the preload of the rod 62. respective spring 35, 36; for this purpose, the spine of section 44 comprises a hole or cavity 68 (Figure 6) and the spine of section 51 (Figure 2) comprises a similar cavity that allows access to each nut 67 by means of a key. The preload of each spring 35, 36 is precisely adjusted by means of the respective nut 67, to compensate for the action of the springs 35 and 36 and to minimize the effort required by the operator to 52/68 move the bell 7 along the work table. Since each mechanism 23, 24 rotates in the respective first articulated member defined by the section 37, 44, the tension of each spring 35, 36 is varied by a respective lever member 69. More specifically, each lever member 69 comprises two parallel levers 71 similar (Figures 4 and 5) pivoting about a pin 72 (Figure 2) fitted to the wings 39 of the section 37 in the case of the mechanism 23 and around the pin 73 fitted to the wings 45 of the section 44, in the case of the mechanism 24. The ends of each pair of levers 71 are housed within two parallel slots 74 (Figure 5) at the outer end of the respective piston 57; the two levers 71 are hinged to the end of the piston 57 by means of an additional bolt 76; and each section 37, 44 comprises a bolt 77 (Figure 3) against which each pair of levers 71 is seized in the limit position shown in Figures 2 and 3. Bolts 72 and 73 of the respective sections 37 and 44 are additionally located away from the respective second stops 64 of the respective bolts 40, 42 and 48, 49 and, are therefore eccentric with respect to the bolts 42 and 49 of the bars 27. Consequently, when each pair of levers 71 rotates from the position 52/68 against the respective bolt 77, the respective piston 57 moves closer to the disc 55 to reduce the preload of the respective spring 35, 36. Therefore, the disc 55 defines the other limit stop when the levers are rotated. 71 and, hence, the respective mechanisms 23, 24 towards the bent position shown by the line of dots and dashes in Figure 3 and Figure 5. The duct 5 as described, operates as follows. Using the handle 9, the operator can move the bell 7 angularly about the axis 14, by rotating the connection 11 on its bearing or along the work table or, vertically towards the source of smoke or gases for its removal. More specifically, starting from the position of FIGS. 1 and 2, the bell 7 moves away from the connection 11 by the bending mechanism 23 and hence from the rigid segment 18 of the conduit 5 with respect to the section 37 and the connection 11 and, moves towards the connection 11 by the bending mechanism 24 with respect to the section 44. However, the location of the bell 7 normally includes moving it both vertically and radially by rotating one or both of the mechanisms 23 and 24 with respect to sections 37, 44. By virtue of the articulated parallelogram connection of each pair of bars 26, 27, the rotation of the 52/68 mechanism 23 causes section 44 to move parallel thereto, so that both mechanism 24 and segment 19 also move parallel thereto; and, similarly, the rotation of the mechanism 24 with respect to the section 44 causes the section 51 to move parallel thereto. Finally, by properly folding the bracket 22, the bell 7 is rotated to position the lower edge of the bell as required with respect to the work station table. In the embodiment of Figure 7, in which some parts similar to those of Figure 1 are indicated using the same numbering system, the segments 18 and 19 again comprise a rigid wall 20; and the mechanisms 23 and 24 are again defined by a pair of bars with U-sections 26 and 27 between which the respective springs 35 and 36 are inserted (see also Figures 3-5) although, in this case, they are shorter and they are not directly connected to each other. More specifically, the bar 26 of each mechanism 23, 24 is adjusted, for example, welded or bolted, to an annular bracket 78 in turn adjusted in some known manner to the end of the corresponding segment 18, 19; the bars 26 and 27 of the mechanism 23 are connected in the form of an articulated parallelogram to the articulated element 37 and to a second articulated element 52/68 defined by an additional U-shaped section 79; and section 79 is connected by bolts 46 and 47 to bars 26 and 27 only and comprises a hole or cavity similar to that of section 51. Bars 26 and 27 of mechanism 24 are connected in the form of an articulated parallelogram to a articulated element defined by an additional U-shaped section 81, which is separated from the section 79 and is rigidly adapted, for example, by means of two bolts 83, to an additional annular bracket 82 adapted in some known manner to the end of segment 18 adjacent to flexible portion 21; and the bars 26 and 27 of the mechanism 24 are connected to the section 51 in the same manner as the mechanism 24 of Figure 1. When the segment 18 of Figure 7 is rotated together with the mechanism 23 with respect to the section 37 , the section 81 also rotates integrally with the segment 18, so that the segment 19 and the mechanism 24 also rotate with respect to the section 37. In turn, the mechanism 24 can be rotated with respect to the section 81 independently of the mechanism 23. In the two embodiments of Figure 1 and Figure 7, the mechanisms 23 and 24 can be housed within segments 18 and 19 and are protected by sealing rings to prevent dust or particles 52/68 suspended in the fumes settle within the mechanisms. If defined by a flexible wall, segments 18 and 19 of Figure 1 are supported by mechanisms 23 and 24, which have the self-supporting feature, and segments 18 and 19 of Figure 7 can be supported by any known type. of support structure, possibly within the segments. In comparison with known conduits, the advantages of the conduit according to the present invention will be clear from the preceding description. In particular, the channel 34 of each mechanism 23, 24 provides full protection to both the tube 54 and the respective compensating springs 35, 36; and the articulated parallelogram connection of the bars 26 and 27 provides for stable rotation of the mechanisms 23 and 24. In addition, the rod 62 and the nut 67 provide the precise adjustment of the preload of each spring 35 and 36 to obtain the better balance; and the connection of the rod 62 to the levers 71 provides the variation of the spring preload 35, 36, as a function of the bending angle of the mechanism 23, 24, with respect to the corresponding articulated element 37, 44, 81. Clearly, changes can be made to the flues for smoke and gases, as described and illustrated in 52/68 without departing, however, from the scope of the accompanying claims. For example, the rod 62 may be threaded only at the ends 61 and 63, in opposite manner along its entire length; the angle of the plane P with respect to the axis 14 can vary according to the type of application; disc 55 may be welded to tube 54, as opposed to the use of a bolt or screw; and, the flange 64 may be dispensed with and the spring stop 35, 36 may be defined by the same nut 67. In addition, the bars 26 and 27 may have a curved section, as opposed to a U-shaped section; the lever member 69 may be defined only by a lever 71 and / or the wings of one or more of the sections 37, 44, 51, 79, 81 may be located outwardly of said bars 26; and the connection 11 may be mounted on the roof, may be adapted to a support at a level higher than that of the work station and may be connected to a centralized suction system, as opposed to being directly connected to a single vacuum cleaner. 52/68

Claims (2)

1. CLAIMS: 1. A general purpose conduit for transporting harmful fumes or gases from a work station and comprising: a connection for connecting with a flexible conduit portion, the connection rotates around its own axis; at least one segment of the conduit is connected to the flexible conduit portion; an articulated mechanism for varying the angular position of the conduit segment with respect to the connection, and compensating spring means; characterized in that the mechanism comprises a pair of bars connected to one another in the form of an articulated parallelogram and forming a substantially closed channel; the spring means comprises a spiral compression spring housed in the channel and connected so as to operate in a varied manner in accordance with the angular position of the conduit segment with respect to the connection. A conduit according to claim 1, characterized in that the conduit segment can be rigid or flexible and the articulated mechanism is located inside or outside the conduit segment. A conduit according to claim 2, characterized in that the pair of bars comprises a first bar having a U-shaped section and whose spine is adapted to the exterior of the conduit segment and a second one 52/68 bar which has a U-shaped section and which is located opposite to the first bar; the wings of the second bar are inserted between the wings of the first bar to form the channel; the articulated parallelogram comprises a pair of articulated elements and a first articulated element of the pair is fixed to the connection. 4. A duct according to claim 3, characterized in that the spring is inserted inside a rigid tube adapted to the wings of the second bar, the spring is compressed between a first stop fixed to the tube and a second stop and a lever member, articulated to the first articulated element, it is connected to the second stop. A conduit according to claim 4, characterized in that the second stop is fitted to a rod inserted into the spring, a sliding member inside the tube is fitted to the rod and is hinged to the lever member. A conduit according to claim 5, characterized in that the rod comprises at least one threaded portion to which a nut is screwed to secure the second stop and to adjust the preload of the spring. A conduit according to one of the preceding claims 4 to 6, characterized in that the lever member pivots about a bolt, located at 52/68 so that the preload of the spring varies as a function of the rotation of the mechanism with respect to the first articulated element. A conduit according to claim 7, characterized in that the bars are articulated to the first articulated element by means of two respective bolts, the bolt of the lever member being located further away from the second stop than each of the respective bolts. A conduit according to one of the preceding claims 6 to 8, characterized in that the first stop comprises a disk having an orifice and being fixed inside the tube, the second stop comprises a flange that slides along the rod and It is pushed by the spring against the nut. A conduit according to claim 9, characterized in that the sliding member comprises a piston having at least two piston rings made of low friction material and for guiding the piston along the inner surface of the tube; the rod has a second threaded portion that engages a threaded hole in the piston. A conduit according to claim 10, characterized in that the piston is clamped against the disk to define a trip end of the lever member; 52/68 the first articulated element comprises a stop defining the other end of the travel of the lever member. 12. A conduit according to claim 11, characterized in that the piston terminates out of the tube with a pair of slots.; the lever member comprises two similar parallel levers inserted into the slots and a through bolt is provided, perpendicular to the slots, for connecting the levers in an articulated manner to the piston. A conduit according to one of the preceding claims 3 to 12, characterized in that each of the articulated elements comprises a section in the shape of a U, whose wings are inserted between the wings of the first and second bars; the U-shaped section of the first articulated element is fixed to the connection by a fixed bracket to the outside of the connection. A conduit according to claim 13, characterized in that the U-shaped section of the second articulated element comprises a cavity that allows adjusting the nut on the rod. A conduit according to claim 13 or 14, wherein the section of the flue passage is circular, characterized in that the conduit segment comprises a rigid cylindrical wall; the first bar is fixed to the outside of the duct segment by means of at least two 52/68 fixed elements along a wall generating line. A conduit according to claim 13 or 14, wherein the section of the flue passage is circular, characterized in that at least one segment of conduit forms a first conduit segment comprising a rigid cylindrical wall; the first bar is fixed to the exterior of the first segment of conduit, along a generating line of the wall, by means of an annular bracket that surrounds the wall. A conduit according to one of the preceding claims, characterized in that the first conduit segment is connected by a second flexible conduit portion to a second conduit segment; the second conduit segment is provided with a second articulated mechanism and the two articulated mechanisms are similar. 18. A conduit according to claim 13 and 17, characterized in that the pair of bars of the second mechanism are connected in the form of an articulated parallelogram to a first and a second articulated elements; the second articulated element comprises a cavity that allows adjusting the respective nut on the corresponding rod. 19. A conduit according to claim 15 and 17, 52/68 characterized in that the two articulated mechanisms have a common articulated element; the first bar of the second mechanism is fixed to the second segment of conduit by means of a corresponding pair of elements and the other articulated element of the second articulated mechanism is connected only to the respective pair of bars. 20. A conduit according to claim 19, characterized in that the axes of the respective bolts of the first articulated element lie in a plane (P) at an angle practically of 45 ° with respect to the axis of the connection; the bolts of the bar pairs of the articulated mechanisms are arranged in the form of a trapezoid, so as to maintain the two conduit segments at an angle to each other. 21. A conduit according to claim 16 and 17, characterized in that the articulated mechanisms are independent of each other; the first bar of the second mechanism is fixed to the second segment of conduit by means of a respective bracket that surrounds the respective cylindrical wall. A conduit according to claim 21, characterized in that the first articulated member of the second mechanism is fitted to a bracket adapted to one end of the first conduit segment; the second articulated element of each of the mechanisms is 52/68 connected to the respective two bars only. A conduit according to one of the preceding claims 17 to 22, characterized in that the second conduit segment is connected to a fume or gas conveyor element, by means of a third portion of flexible conduit. 24. A conduit according to one of the preceding claims, characterized in that the connection is connected to a vacuum cleaner fitted to a fixed or movable support, practically at the level of the work station or at a lower level. 25. A conduit according to one of the preceding claims 1 to 23, characterized in that the connection is mounted to the ceiling or adjusted to a support at a level higher than that of the work station.
2. 2/68