| 1. | Work bench (1), preferably for ventilation engineers, said work bench (1) including a framing (2) that supports a working top plate (3) included in the work bench (1), c h a r a c t e r i z e d in that it includes a number of pairs of support rollers (8,9), that in active position projects through slots (10) in the working top plate (3), said pair of support rollers (8,9) may also assume an inactive position below the working top plate (3). |
| 2. | Work bench (1) according to claim 1, c h a r a c t e r i z e d in that within each pair of support rollers (8,9) the distance between the support rollers (8,9) is adjustable in a direction transverse to the axes of rotation of the support rollers (8,9). |
| 3. | Work bench (1) according to claim 1 or 2, c h a r a c t e r i z e d in that the pair of support rollers (8,9) are carried by a carrying device (11) that is pivotally connected to a frame (4) included in the framing (2). |
| 4. | Work bench (1) according to claim 3, c h a r a c t e r i z e d in that in active position of the support rollers (8,9) the carrying device (11) is fixed relative to the frame (4). |
| 5. | Work bench (1) according to any of the claims 14, c h a r a c t e r i z e d in that the framing (2) includes two pairs of legs (5), the length of said pairs of legs (5) being adjustable. |
| 6. | Work bench (1) according to claim and 5, c h a r a c t e r i z e d in that the pairs of legs (5) are telescopic. |
| 7. | Work bench (1) according to any of claims 16, c h a r a c t e r i z e d in that it includes a holding arm (14) that pivotally supports a cutting disc (20). |
| 8. | Work bench (1) according to any of claims 17, c h a r a c t e r i z e d in that it at one of its short sides is provided with wheels (28), that may be brought to assume an active position or an inactive position. |
| 9. | Work bench (1) according to claim 8, c h a r a c t e r i z e d in that the wheels (28) are mounted in holders (29), that are detachably mounted in a frame (4) of the framing (2). |
| 10. | Work bench (1) according to any of claims 19, c h a r a c t e r i z e d in that a storage box (16) may be mounted on the work bench (1) in the area of one of its short sides. |
Prior Art When ventilation engineers are going to cut or in another way work ventilation ducts the working situation is often at present such that the ventilation engineer has no natural place to work in but he/she is reduced to effect cutting and/or other working while going down on his/hers knees on the floor. This is extremely un-satisfying since electrically powered rotating cutters or the like are used during cutting and the risk of being damaged by such a rotating cutter or the like is increased when the ventilation engineer is not in a controlled working position.
A work bench is previously known, said work bench being marketed under the name VENTIKAP-2000 by which ventilation ducts may be cut while the worked ventilation duct is supported by a number of rotatable rollers along the length of the duct. A rotating cutter is pivotally supported by a rack and a from above lowered fixing means may be brought to contact the ventilation duct in the area of cutting. This work bench may only be used for cutting of ventilation ducts and has no means for adjustment to different diameters of the ventilation ducts.
Objects and Features of the Invention The present invention aims at providing a work bench of the type defined above, the primary aim of said work bench being to essentially improve the working situation of ventilation engineers by offering an ergonomical acceptable working position at a location that is chosen by the ventilation engineer himself. A further object of the present invention is that the work bench in a satisfying way allows cutting of ventilation ducts having different diameters.
Still a further object of the present invention is that it is possible to use the work bench also for other working operations than cutting of ventilation ducts. Still a further object of the present invention is that the work bench is easy to transport. A further object of the present invention is that the work bench may be used when transporting the tools of the ventilation engineer. Still a further object of the present invention is that said tools are easily accesible to the ventilation engineer when he/she is working at the work bench.
Brief Description of the Drawings Below an embodiment of the invention will be described, reference being made to the accompanying drawings that show: Fig. 1 a perspective view inclined at an angle from above of a work bench according to the present invention; Fig. 2 a perspective view inclined at an angle from below of the work bench according to Fig. 1; Fig. 3 a perspective view according to Fig 1 where the work bench is equipped with a storage box; Fig. 4 an exploded view for certain items of the perspective view according to Fig. 3 and a downhanging support roller structure for the ventilation ducts; Fig. 5 a perspective view of the work bench according to the invention where cutting of ventilation ducts is effected by a rotating cutter; Fig. 6 a side view of Fig. 5; Fig. 7 a schematic side view of a pair of the support rollers that supports the ventilation ducts, the adjustment possibility of said support rollers being shown; Fig. 8 a top view of a pair of support rollers; Fig. 9 a perspective view of the work bench according to the invention in folded position, where the work bench is equipped with wheels; and Fig. 10 a side view of the work bench according to Fig. 9, where it is used as a trolley.
Detailed Description of Preferred Embodiments of the Present Invention The work bench 1 disclosed in Figs. 1-4 includes a framing 2 and a working top plate 3, said plate 3 being supported by a frame 4 of the framing 2, said framing 2 in the disclosed embodiment also including two pairs of legs 5 that are pivotally connected to the frame 4. As is evident from Figs. 1-4 the pairs of legs 5 are locked in their outwards bent positions by bars 6 that consist of parts 6a, 6b that on one hand are hingedly connected to each other and on the other hand are hingedly connected to the frame 4 and the pairs of legs 5 respectively. The bars 6 may be brought to assume a somewhat buckled position where the pairs of legs 5 are locked in their outwards bent positions.
As is evident from Figs. 1-4 the pairs of legs 5 are adjustable as regards their length, i. e. the height of the work bench 1 when the pairs of legs 5 are in their outwards bent positions. The adjustment of the length of the pairs of legs 5 is effected in the shown embodiment by having the pairs of legs 5 telescopically designed and that locking bolts 7 may be brought to co-operate with through-going holes in the parts of the pairs of legs 5 that are telescopically movable relative to each other. Said adjustment of the length of the pairs of legs 5 is important on one hand to set the work bench 1 at an individually adjusted working height and on the other hand in connection with the folding of the work bench 1, said folding being described in more detail below with reference to Fig. 9.
The work bench 1 according to the invention also includes a structure having a number of rotatable support rollers 8 and 9. According to the preferred described embodiment the support rollers 8 are stationary while the support rollers 9 are adjustable. In active position each pair of support rollers 8 and 9 are received in a slot 10, said slot 10 extending transverse to the longitudinal direction of the working top plate 3. In the disclosed embodiment three pairs of support rollers 8 hand 9 are provided and consequently three slots 10.
The structure involving the support rollers 8 and 9 includes a carrying device 11, see especially Fig. 2, that is pivotally connected to the frame 4. As is most evident from Fig. 2 the pivotally connected carrying device 11 may be locked in a raised position when the pairs of support rollers 8 and 9 in active position project through the slots 10. Said locking of the carrying device 11 in raised position is effected in the disclosed embodiment by means of a locking arm 12 that is hingedly connected to the carrying device 11, said locking arm 12 may be brought to engage a holding means 13 that is provided on the frame 4, said holding means 13 keeping the locking arm 12 in the position shown in Fig. 2 where the carrying device 11 assumes it raised position, i. e. the position when the support rollers 8 and 9 project through the slots 10 and assume their active positions.
An important feature of the work bench 1 according to the present invention is that the carrying device 11 is pivotally connected to the frame 4. By this it is possible that the carrying device 11 also can assume a lowered position, see Fig. 4, where the engagement between the locking arm 12 and the holding means 13 has ceased and the carrying device 11 depends freely from the frame 4. As if evident from Fig. 4 also the support rollers 8 and 9 assume a depending position, i. e. they are no longer positioned in the slots 10.
This means that the working top plate 3 is completely planar without any objects that project above its working surface.
In this way the working top plate 3 may be used for working operations that demand a planar working surface.
As is evident from Figs. 1-4, according to the disclosed embodiment, the work bench 1 is provided with a holding arm 14 for a rotating cutting disc that will be described more in detail below. In Fig. 4 it is indicated that said holding arm 14 is mounted at the work bench 1 by means of an attachment device 14a, in the shown embodiment in the shape of a square tube, that is pushed into an opening (not shown) in the frame 4 and fixed by means of a locking bolt (not shown) or the like. The holding arm 14 includes a portion 15 that is hinged relative to the rest of the holding arm 14, said rotating
cutting disc being attached to said hinged portion 15, see below.
As can be seen from Figs. 3 and 4 a storage box 16, having a circumferential rim 17, may be hung on the frame 4 of the work bench 1, a bent edge portion 18 of the storage box 16 constituting its hanger means. The box 16 is intended for storage of tools used by the ventilation engineer in his work.
With reference to Figs. 5-8 the primary work task, that the work bench 1 according to the present invention is intended for, will be described below, said work task being cutting of ventilation ducts 19, said ducts in Figs. 5-7 having the shape of a spiral tube. As can be seen from Figs.
5 and 6 a spiral tube 19 is positioned on the work bench 1 in such a way that said spiral tube 19 is supported by the pairs of support rollers 8 and 9. All support rollers 8 have an essentially coinciding axis of rotation and all support rollers 9 are brought to have an essentially coinciding axis of rotation since the support rollers 9 are adjustable as regards their positions, this being described more in detail below. Within each pair of support rollers the axes of rotation of the support rollers 8 and 9 are essentially parallel to each other and extend in the longitudinal direction of the work bench 1. A rotating cutter 20 having a cutting disc 21 is mounted on the hinged portion 15 of the holding arm 14, and by this arrangement the cutting disc 21 may be swung towards and away from the spiral tube 19. The actual cutting of the spiral tube 19 if effected by having the cutting disc 20 swung to contact the spiral tube 19 for removing material from said tube 19 simultaneously as the spiral tube 19 is rotated by the ventilation engineer in direction of the arrow 22, see Fig. 5. The cutting is finished when the spiral tube 19 has been rotated one revolution in direction of the arrow 22.
In Figs. 7 and 8 a pair of support rollers 8 and 9 are shown more in detail. It is thereby seen that the support rollers 8,9 rotatably are supported in a first holder 23 and a second holder 24 respectively, said holders 23,24 in their turns being supported by a plate 30, said plate 30 in its turn
being supported by the carrying device 11, see Fig. 2. The holders 23 and 24 may for instance be screwed to the plate 30, said plate 30 in its turn may be welded to the carrying device 11 top.
Since there are spiral tubes 19 having different diameters it is important that the work bench 1 according to the present invention may be used for spiral tubes having different diameters. In order to realise this the second holder 24 of each pair of support rollers is adjustable as regards its position in the slot 10, said holder 24 supporting the support roller 9. As can be seen especially from Fig. 7 the second holder 24 of the support roller 9 is displacable in the plane of the paper of Fig. 7, said second holder 24 being displacable along a rail 25 provided on the plate 30, said holder 24 may be fixed in said rail 25 by means of a locking pin 26. In Fig. 7 is disclosed how the adjustment of the second holder 24 of the support roller 9 brings about that spiral tubes 19 having essentially different diameters may be received by a pair of support rollers 8 and 9. Generally, as pointed out above, the axes of rotation of the support rollers 8,9 in one pair are parallel but separated in a transverse direction, said axes of rotation being essentially parallel to the axis of rotation of the spiral tube 19 when rotated according to the arrow 22.
In Fig. 9 the work bench 1 according to the present invention is shown in folded position that is suitable for transporting the work bench 1. In that position the work bench 1 may be carried in a handle 27 that is mounted on the frame 4. As pointed out above the adjustment as regards the length of the pairs of legs 5 is important as regards the position of transport of the work bench 1. In the position of transport shown in Fig. 9 the pairs of legs 5 have a minimum length, i. e. the telescopically displacable portions of the pair of legs 5 are inserted as for as possible into each other, this allowing the pairs of legs 5 to be folded to the position of Fig. 9 without interfering with each other.
In order to simplify the transport of tools and other accessories used by the ventilation engineer in his work the work bench 1 is provided with wheels 28 in the embodiment
shown in Figs. 9 and 10, said wheels 28 being rotatably received in third holders 29 that are detachably mounted in the frame 4 of the work bench 1. Said holders 29 are mounted in the frame 4 by means of a locking bolt or the like and they may assume two different positions, i. e. an inactive position according to Fig. 9 and an active position according to Fig.
10. In order to displace the holders 29 from one position to another they are turned 180°.
By providing the work bench 1 with wheels 28 and mount its holders 29 in active position the work bench 1 may be used as a trolley, this being shown in Fig. 10. Thereby one of the pairs of legs 5 is bent outwards and the space between the outwardly bent pair of legs 5 and the associated portion of the frame 4 may be used to store tools and other accessories needed by the ventilation engineer in his work. The inclination of the work bench 1 relative to the surface in Fig. 10 is intended to indicate a position when the ventilation engineer raises the end of the work bench 1 being void of wheels and the ventilation engineer pushes the work bench 1 ahead of him like a trolley. Since the distance between the location where the ventilation engineer parks his car and the actual working site may be far it is of extreme benefit that the work bench 1 according to the present invention may be used as a transporting trolley.
Feasible Modifications of the Invention An essential feature of the present invention is the carrying device 11 with the support rollers 8 and 9. In the embodiment described above the carrying device 11 is pivotally connected to the frame 4. However, the invention is in no way restricted to such a structural design. The device that carries the support rollers may be designed in several different ways and further the means for raising and lowering said device that carries the support rollers may be of different type. In exemplifying and not restricting purpose it may be mentioned that raising and lowering of the support rollers may be effected by means of some type of rack device or by means of hydraulic cylinders. Important in connection with the present invention is that the support rollers may be
brought to assume an active position when they project through the slots and an inactive position when they are located below the working top plate.
As regards the possibility to adjust the length of the pairs of legs this can be effected in another way compared to what has been described above. Of course the legs must not be coupled in pairs.