HEIDEMAN, Gerben Johan (Olmenstraat 57, TG Winterswijk, NL-7101, NL)
OONK, Marcel (Tuunterstraat 27, EE Winterswijk, NL-7101, NL)
HEIDEMAN, Gerben Johan (Olmenstraat 57, TG Winterswijk, NL-7101, NL)
| CLAIMS 1. A method for asphalting a surface in which at least one manhole is provided, which method comprises the following steps: 5 a) installing a manhole frame in said at least one manhole; b) covering said at least one manhole; c) laying an asphalt layer of a specified height over the surface to be asphalted, using an asphalt machine; and d) making said at least one manhole accessible, 0 wherein the manhole frame is lifted so as to adjust its height to the asphalt layer that has been or is to be laid, characterised in that use is made of a vertically adjustable supporting device which is supported on the bottom of the manhole during the lifting of the manhole frame for supporting the manhole frame at least while it is being5 lifted. 2. A method according to claim 1 , characterised in that the manhole frame is lifted prior to step c). 3. A method according to claim 1 , characterised in that the manhole frame is lifted after step d) but prior to the rolling of the asphalt layer. 0 4. A method according to one or more of the preceding claims, characterised in that steps b) - d) are repeated several times so as to provide a road surface built up of several layers of asphalt, wherein the manhole frame is raised each time after a preceding asphalting step. 5. A supporting device for a manhole frame intended for use in a5 method according to one or more of the preceding claims, said supporting device comprising a foot by means of which the supporting device in use is supported on a bottom of a manhole, and supporting means supported by the foot which in use support the manhole frame, whilst height adjusting means are provided for adjusting < ■ the desired height of the supporting means for the manhole frame. 0 6. A supporting device according to claim 5, characterised in that orientation adjusting means are provided for adjusting the orientation of the manhole frame relative to the horizontal. 7. A supporting device according to claim 5 or 6, characterised in that indication means are provided, which indication means extend to above the surface to be asphalted when the manhole frame is being supported. 8. A supporting device according to claim 7, characterised in that the indication means comprise operating means for operating the supporting device. 9. A supporting device according to one or more of claims 5-8, characterised in that the operating means can be moved between an operative position and a non-operative position. 10. A supporting device according to claim 9, characterised in that the operating means are coupled with the supporting means, so that the support by the supporting means is removed when the operating means are moved from the operative position to the non-operative position. 11. A supporting device according to one or more of ctaims 5-10, characterised in that the supporting device comprises lifting means by means of which a manhole frame, after an asphalt layer has been laid, is lifted within the framework of the operations for asphalting a surface. 12. A supporting device according to claim 11 , characterised in that the lifting means comprise at least one lifting device for lifting the entire manhole frame and/or at least one local lifting device for locally lifting the manhole frame. |
DESCRIPTION The present invention, according to a first aspect thereof, relates to a method for asphalting a surface in which at least one manhole is provided, which method comprises the following steps: a) installing a manhole frame in said at least one manhole; b) covering said at least one manhole; c) laying an asphalt layer of a specified height over the surface to be asphalted, using an asphalt machine; and d) making said at least one manhole accessible, wherein the manhole frame is lifted so as to adjust its height to the asphalt layer that has been or is to be laid. The manhole frame may be a temporary frame or (part of) a permanent manhole frame. The manhole frame may be provided with a cover, in which case the placing of the manhole frame in fact takes place simultaneously with step b).
In a known method for asphalting a road surface in which a manhole is provided, for example for rainwater drainage, a steel plate is laid over the manhole on the subgrade. Following that, a layer of rubble is deposited as a substrate layer for asphalt to be subsequently laid. The steel plate is then traced by means of a metal detector and cleared by scooping the rubble off the steel plate, after which the steel plate is removed. Subsequently, a manhole frame provided with a downwardly extended shaft is placed in the manhole and manually adjusted so that it projects above the layer of rubble to a desired extent, after which a preliminary or definitive cover is placed on the manhole frame. Following that, a layer of asphalt is laid over the layer of rubble by means of an asphalt spreader or asphalt machine, after which the layer of asphalt may be subjected to a finishing treatment, for example rolling. Because the manhole frame and the cover float in the asphalt, the manhole frame is depressed along with the upper surface of the asphalt when the asphalt is being rolled and the two will remain aligned with each other. Usually a road surface is built up of a number of layers of asphalt. Before a second (or next) layer of asphalt is provided, the asphalt surrounding the outer edge of the manhole is manually removed for raising the manhole frame to the desired height again, for example by pulling it up by means of a crane. Once the manhole frame has been readjusted, the space between the layer of asphalt that is already present and the outer edge of the manhole is manually filled with asphalt and the manhole frame is fixed at the adjusted height, using asphalt which is likewise manually provided. Then the next layer of asphalt can be provided by means of a asphalt machine. This method is repeated for each next layer of asphalt.
The known method is very labourious. With each new layer of asphalt, no matter how many layers are already provided, the asphalt from the previously laid layer of asphalt surrounding of the manhole frame must be removed, from the upper edge of the manhole frame in some cases as deep as to the layer of rubble, in order to clear the manhole frame so as to be able to pull it up. This must be done with due care, and frequently part of the asphalt surrounding the manhole frame is pulled up from the road along with the manhole frame. In addition, the quality of he asphalt layer surrounding the manhole frame is relatively low, due to the fact the space surrounding the manhole frame is repeatedly cleared of asphalt and manually filled with asphalt again.
Accordingly it is an object of the present invention to provide a method as described in the introductory paragraph which is less labourious. This object is according to the present invention accomplished in that use is made of a vertically adjustable supporting device which is supported on the bottom of the manhole during the lifting of the manhole frame for supporting the manhole frame at least while it is being lifted. With the known method, there is a risk that the manhole frame will fall into the manhole when the manhole frame is being cleared prior to being lifted. With the known method, there is a chance that the asphalt will be damaged during the aforesaid lifting if the manhole frame is insufficiently cleared and/or an insufficiently controlled pulling force is exerted thereon by means of a crane. These drawbacks are eliminated by the invention. By using a supporting device prior to and during the lifting operation, which supporting device is disposed under the circumferential wall to be lifted and which will continue to support said circumferential wall during the lifting operation, the manhole frame can first and foremost not fall into the manhole. In the second place, a controlled force can be exerted on the manhole frame by means of the supporting device, and that in such a manner that the manhole frame will retain the desired orientation at all times, which orientation is ensured by the supporting device. Because the supporting device is supported on a bottom of the manhole, a large force can be developed from said bottom, and the supporting device which is, at least to a large extent, disposed within the manhole will hardly, if at all, interfere with the asphalting operation. The lifting force can thus be exerted on the manhole frame in a controlled manner, adequately distributed over said manhole frame, this in contrast to the known method, which makes use of a crane. While the manhole frame is subsequently held in its correct position by the supporting device, the manhole frame can be fixed in said position relative to the subgrade by means of manually provided asphalt. The supporting device can be removed prior to the asphalting operation in order to prevent it from being damaged during said asphalting by means of the asphalt machine or during the rolling of the new asphalt layer.
From US 5,435,662 A there is known a method for asphalting a road surface provided with a manhole cover, wherein use is made of a marking device which can mark the position of, for example, a manhole cover in a newly laid asphalt layer. After the asphalting operation, a manhole cover provided with the marking device can be easily traced by means of the marking device. The asphalt can then be removed from the manhole cover so as to clear the manhole cover, making it possible to adjust a cylindrical element disposed thereunder. DE 20 2008 013 095 U1 describes an adjusting device for adjusting the installation height of shaft walls in asphalted roadways. The adjusting device is to be placed with its feet on the road surface for subsequently adjusting a cover for the shaft wall by pulling the cover up. With said device, the cover must be cleared prior to being adjusted, because the adjusting device engages the cover from above. Furthermore, the adjusting device seems to be of relatively light construction, because the device only needs to be suitable for adjusting a cover. The device is not suitable for pushing a manhole frame up through a layer of asphalt.
In a preferred embodiment of a method according to the present invention, the manhole frame is lifted prior to step c). Thus, the manhole frame can be lifted to approximately the correct height prior to the asphalting operation, as discussed with reference to the known method, the difference being that a supporting device makes it possible to lift the manhole frame in a very controlled and gradual manner.
In an alternative embodiment of the present invention, the manhole frame is lifted after step d) but prior to the rolling of the asphalt layer, or at least prior to the rolling of the part of the asphalt layer in which the manhole frame is disposed. The asphalt layer is in that case laid over the entire manhole frame. The manhole frame can subsequently be largely cleared of asphalt, so that the adjusting means for the vertical adjustment can be reached and the manhole frame is pushed up "through the asphalt" to above the newly laid asphalt layer by means of the supporting device. In a finishing operation, the asphalt layer is rolled, thereby aligning the upper edge of the manhole frame with the asphalt.
In a preferred embodiment of the present invention, steps b) - d) are repeated several times so as to provide a road surface consisting of several layers of asphalt, with the manhole frame being raised each time after a preceding asphalting step. The manhole frame can be positioned at a higher level, for example by means of the supporting means, after a layer of asphalt has been laid. Alternatively, a new circumferential wall segment can be placed on top of the manhole frame for the preceding layer of asphalt.
To prevent the supporting means from causing damage to the supporting device as a result of forces being exerted on the subgrade during the asphalting operation, it is advantageous if the support provided by the supporting device is removed prior to step b). The present invention, according to a second aspect thereof, relates to a supporting device for a manhole frame for use in the first aspect of the present invention, said supporting device comprising a foot by means of which the supporting device in use is supported on a bottom of a manhole, and supporting means supported by the foot which in use support the manhole frame, whilst height adjusting means are provided for adjusting the desired height of the supporting means for the manhole frame. The height adjusting means may comprise mechanical height adjusting means, such as a spindle, for example. The height adjusting means may alternatively comprise hydraulic or pneumatic adjusting means. It is advantageous in that case if the adjusting means are suitable for stepless adjustment of the height of the manhole frame. As already indicated before, the desired height of the manhole frame is determined by the height of the asphalt layer to be laid, among other factors.
Preferably, orientation adjusting means are provided for adjusting the orientation of the manhole frame relative to the horizontal. The manhole frame preferably extends perpendicularly to the final road surface at the location of said at least one manhole. There is a possibility that the road surface is locally oriented exactly horizontal, but usually this is not the case. As a rule, roads are constructed to be convex so as to effect an adequate drainage of rain water to the side of the road surface, in addition, a road itself may be oriented at a certain angle. In both cases it is preferable if the manhole frame is oriented at an angle corresponding to the local orientation angle of the road surface relative to the vertical. The supporting device can provide three bearing points on which the manhole frame can be positioned. Three bearing points provide a stable bearing surface. If one or more bearing points can be individually adjusted for height, it is possible to adjust the orientation of the manhole frame in this way. A manhole cover to be placed on the manhole frame can in that case be laid on the manhole frame in alignment with the road surface.
To prevent the supporting device from being damaged by an asphalt machine and/or a roller driving over the manhole frame while the manhole frame is being supported by the supporting device, it is preferable if indication means are provided, which indication means extend to above the surface to be asphalted when the manhole frame is being supported. This prevents the risk that a cover is placed on the manhole frame and asphalting is started while the manhole frame is still being supported by the supporting means.
In a preferred embodiment of the present invention, the indication means comprise operating means for operating the supporting device. The operating means may comprise a shaft with a handwheel for adjusting the height of the supporting device, and thus the height of the manhole frame, and/or the orientation of the manhole frame. A user-friendly device is provided if the operating means can be moved between an operative position and a non-operative position. In a non-operative position, the operating means must have been removed or at least not extend above the manhole frame. This means that they must be countersunk in the road surface. To realise better ergonomics, the operating means can be moved upwards to the operative position. Thus, the operating means are also indication means in the sense of the preceding paragraph.
It is preferable if the operating means are coupled with the supporting means, so that the support by the supporting means is removed when the operating means are moved from the operative position to the non-operative position. Thus a user can see whether or not the support of the manhole frame by the supporting means has been released.
It is preferable if the supporting device comprises lifting means by means of which a manhole frame, after an asphalt layer has been laid, is lifted within the framework of the operations for asphalting a surface. The manhole frame can thus be lifted somewhat in a simple manner each time a new layer of asphalt is (to be) laid.
In order to be able to adjust the position of the manhole frame as desired, it is preferable if the lifting means comprise at least one lifting device for lifting the entire manhole frame and/or at least one local lifting device for locally lifting the manhole frame. Using the former, the height of the manhole frame can be adjusted. Using the latter, also the orientation of the bearing surface for the manhole frame can be adjusted.
The present invention further relates to the use of a supporting device according to the second aspect of the invention in the asphalting of a surface, wherein the supporting device is supported with its foot on the bottom of the manhole and wherein the manhole frame is positioned to project at least partially above the surface to be asphalted, using the supporting device, prior to the asphalting of the surface. The advantages hereof correspond to the advantages described with reference to the first and the second aspect of the invention.
The present invention will be explained in more detail hereinafter by means of an exemplary embodiment and with reference to the appended figures, in which:
Figure 1 is a perspective view of a part of a supporting device according to the present invention;
Figure 2 is a perspective view of the supporting device of figure 1 , disposed in a manhole; and
Figures 3a-3e are sectional views of steps to be carried out when asphalting a road surface in accordance with the present invention. Figure 1 shows a vertically adjustable stamp 1 as the supporting device according to the present invention. The stamp 1 comprises a spindle 2, on which a tubular housing 3 is supported. A rotatable bush 5 provided with internal screw thread is supported on the housing 3 via a bearing (not shown). At the upper side the spindle 2 is surrounded by an inner rotatable bush 6, which is in turn surrounded by a static bush 7, to which arms 8a, 8b, 8c are attached, in which arms keyhole-shaped holes 19 are provided. The bushes 6 and 7 are covered by a flange 9 and a disc 10, respectively, which disc can be rotated via the engaging element 11. The arms 8a, 8b, 8b each accommodate an extension piece 12a, 12b and 12c, respectively, which is held in place by bolts 13 and by shafts 14 that can be rotated by means of handwheels 15. At the ends thereof, bolts 17 provided with a support plate 18 are provided, which bolts are rotatable in brass bushes 16.
Figure 2 shows a stamp 1 in a housing 30 of a storm drain as the manhole. In figure 2, elements corresponding to elements used in the stamp 1 in figure 1 are indicated by the same numerals. The spindle 2 is supported on two tubes 20a, 20b which can be telescoped together, which tubes are provided with through holes 21a and 21b, respectively. The lower tube 20b is connected to a foot 22, which rests on the bottom 31 of the storm drain. The storm drain is provided with a concrete cover 32 at the upper side, in which a circular opening is present. A first layer of asphalt 33 (only a circular part of which is shown here) lies on the cover 32. On said first layer of asphalt 33 lie a second layer of asphalt 33a and a manually provided third layer of asphalt 34, on which a flange-shaped edge 35 of a manhole frame 36 is supported.
Figures 3a-3e show in cross-sectional view successive situations of the manhole and asphalt of figures 1 and 2 when an layer of asphalt is being laid by means of the device, using a method according to the present invention In these figures, too, like elements are indicated by the same numerals.
In figure 1 the upper part of a vertically adjustable stamp 1 is shown partially in cut-away view and partially in sectional view. Figure 2 shows the stamp 1 in a housing 30 of a storm drain, on which a first and a second layer of asphalt 33 and 33a, respectively, and a third auxiliary layer of asphalt 34 for a manhole frame 36 placed on the storm drain 30 is provided. The operation of the stamp 1 will now be explained with reference to figures 1 and 2. The stamp 1 is placed on the bottom 31 of the storm drain 30 with a foot 22. Then a first vertical adjustment of the supporting parts of the stamp 1 is achieved by sliding the tube 20a upwards in the tube 20b to a desired height and passing a pin through mutually aligned pairs of holes 21a and 21 b so as to lock the tubes 20a and 20b together. In this way a relatively rough height adjustment of the spindle 2, which rests on the upper tube 20a, is realised. The spindle 2 has a relatively wide lower part not provided with screw thread and a relatively narrow upper part provided with screw thread. The transition between the relatively narrow part and the relatively wide part forms a stop 4 for the rotatable bush 5. An upper stop may be provided as well. The rotatable bush 5 engages the external screw thread of the upper part of the spindle 2 with its 5 internal screw thread. A static bush 7 is supported on an upper circumferential wall of the rotatable bush 5 via a bearing (not shown), which static bush surrounds an inner rotatable bush 6. At the upper side, the bush 6 is provided with a cover disc 10 which is fixed to the bush 6, to which cover disc an engagement element 11 for a tool is fixedly connected. When the engagement element 11 is engaged and rotated 0 by means of the tool, the inner bush 6 and the rotatable bush 5 are rotated along with the engagement element 11. Since the bush 5 engages the spindle 2 with its internal screw thread, the height of the upper part of the stamp 1 is adjusted by rotating the engagement element 11. It will be understood that, using the present stamp 1, this can be done in a very gradual and controlled manner. Depending on 5 the pitch of the spindle 2, the manhole frame is lifted only a few millimetres with every full rotation of the engagement element 11. The arms 8a, 8b, 8c connected to the static bush 7 move upwards or downwards as the bush 5 rotates. The support discs 18 for the manhole frame 36 follow the movements of the arms 8a, 8b, 8c The height of each individual support plate 18 can be individually adjusted for adapting 0 the bearing surface for the manhole frame 36 formed by the three support plates 18. This will become clearer when looking at the cutaway arm 8c and the extension piece 12c. Near the distal end of the extension piece 12c, a brass bush 16 is mounted in a through hole of the extension piece 12c. The brass bush 16 houses a bolt 17, to the upper end of which a support plate 18 is attached. By rotating the bolt 5 17 relative to the brass bush 16, the bolt 17 is turned into or out of the brass bush 16, thereby adjusting the height of the support plate 18 of the arm 8c. Thus a fine height adjustment can be realised in a comparable manner as with the spindle 2. In fact, this adjustment serves to adjust the height of the support plate 18 on the arm 8c relative to the other two support plates 18 on the arms 8a and 8b, which can be0 individually adjusted for height in a comparable manner. The extension pieces 12a, 12b and 12c are slidably accommodated in the arms 8a, 8b and 8c, respectively. This will now be explained in more detail, again with reference to the cutaway arm 8c. The extension piece 12c is clamped to the upper part of the arm 8c by means of
; . a bolt 13 on the one hand and a rotatable shaft 14 provided with internal screw thread on the other hand. When the handwheel 15 is rotated in anti-clockwise direction, the clamping force on the arm 8c of the bolt 13 on the one hand and the shaft 14 on the other hand is reduced until the extension piece 12c can be pulled in the direction of the centre of the stamp 1 , for example via the handwheel 15. To that 5 end a keyhole-shaped hole 19 is provided in the upper side of the arm 8c. Once the extension piece 12c has been pulled sufficiently far into the arm δc, the shaft 14 will be positioned near the keyhole-shaped hole 19 and can move downwards into the arm 8c through the wide part of the keyhole-shaped hole 19. From that position, the extension piece 12c can be pulled up again at a desired moment and be returned to 0 the position shown in figure 1.
In figures 3a-3e the method according to the present invention is explained in more detail, in this case using the stamp 1 shown in figures 1 and 2. Figures 3a-3e show a subgrade 40, in which a storm drain 30 is present. Disposed in the storm drain 30 is a stamp 1 , only the upper part of which is visible in figures 3a-5 3e. The storm drain 30 is provided with a concrete cover 32, which has a circular opening for the manhole frame 36 and whose upper side is flush with the upper surface of the subgrade 40.
Figure 3a shows a situation in which the stamp 1 supports a manhole frame 36 via three support plates 18 (only one of which is shown in its0 entirety and one is shown in cross-sectional view in figures 3a-3e), and that in such a manner that the flange-shaped upper edge 35 of the manhole frame 36 "floats" above the surface of the subgrade 40. The stamp 1 has to that end been so adjusted by means of the telescopic tubes 20a, 20b (not shown in figures 3a-3e), the rotatable bush 5 and by adjusting the support plates 18 that the manhole frame 36 is5 positioned at the desired height and in the desired orientation relative to the horizontal (read: parallel to the upper surface of the subgrade 40). Note that the shafts 14 and the handwheels 15 extend to above the flange-shaped upper edge 35 of the manhole frame 36.
Figure 3b shows a next step, in which asphalt 41 has been manually0 provided on the upper surface of the subgrade 40 around the manhole frame 36. The asphalt 41 functions to fix the manhole frame in the position adjusted by the stamp 1. The handwheels 15 are still positioned above he flange-shaped edge 35.
Figure 3c shows the next step, in which the extension pieces 12 of
- ; the arms have been lowered through the keyhole-shaped holes (see figure 1 ) in a manner as already explained with reference to figure 1. The manhole frame 36 is now only supported by the manually provided asphalt 41 around the manhole frame 36. The handwheels 15 are now positioned below the level of the flange-shaped upper edge 35, so that the manhole cover 37 can be placed on the manhole frame 36. In this position the subgrade 40 can be asphalted by means of an asphalt machine (not shown).
Figure 3d shows a situation after asphalt has been laid on the subgrade 40. A uniform layer of asphalt 42 is present on the entire subgrade 40, of which layer of asphalt the asphalt that was previously manually provided (indicated at 41 in figures 3b and 3c) forms an integral part. When a new layer of asphalt is to be laid on the layer of asphalt 42, the manhole cover 37 is removed and the extension pieces 12 are returned to the position shown in figures 3a and 3b. When the manhole frame 36 is positioned lower than in the situation shown in figures 3a- 3c, for example after the asphalt has been rolled, the rotatable bush, and thus also the arms 8, will first have to be moved downwards by operating the engaging element 11. Once the support plates 18 have been positioned, the rotatable bush 4 is rotated by means of the engaging element 11 in order to thus raise the support plates 8 and the manhole frame 36 supported thereon. This situation is shown in figure 3e, which is only different from figure 3a in that a first and a second layer of asphalt 42 and 44, respectively, are present on the subgrade 40. The above steps can then be repeated for laying a next layer of asphalt.
Only one embodiment of the method and only one embodiment of a supporting device according to the invention to be used in said method are shown in the appended figures and described in the above description, it will be understood, however, that several variants both of the method and of the supporting device, which may or may not be obvious to those skilled in the art, are possible within the scope of the present invention, which is defined in the appended claims. Thus it is possible, for example, to use a modular manhole frame, in which case a next module, for example a ring, is installed for raising the edge of the manhole frame each time a new layer of asphalt is laid, whilst the manhole frame itself is not lifted. Furthermore, it is not necessary to use a stamp according to the present invention when using the method according to the present invention. In fact, raising and fixing the manhole frame above the subgrade surface can be done in any suitable way. The stamp shown and described herein functions entirely mechanically, but it is also possible to use a stamp which is driven by hydraulic or pneumatic means for raising and lowering a manhole frame.
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