EP0974699B1 - Screed for a road paver - Google Patents

Description

The invention relates to a screed for a paver according to the preamble of claim 1.

Asphalt pavers usually comprise a screed arranged on the back in the direction of installation behind a spreading auger. Such screeds are articulated to the chassis via draw arms so that they float on the material to be installed.

So that different working widths can be realized, it is known to manually attach screed extension parts on each side of such screeds (see e.g. DE-A-2 555 218).

Such screed extension parts are usually attached to the screed by means of fastening screws which pass through in one on the extending through the side wall of the screed provided through openings and through holes provided in a side wall of the screed extension part to be attached. However, such an assembly is time-consuming and requires a great deal of effort from the installer.

The object of the invention is to provide a screed for a paver according to the preamble of claim 1, in which a quick and energy-saving attachment of screed extension parts can take place.

This object is achieved in accordance with the characterizing part of claim 1.

For this purpose, in the case of a screed for a paver with two outer side walls, through-holes for releasably attaching at least one side screed extension part are provided in at least one of the side walls via fastening elements which can be inserted through the through-holes, the fastening elements spring-loaded cylinders. The spring-loaded cylinders each have a piston that is spring-loaded in its starting position, can be hydraulically loaded to move the piston against the spring preload, and can be connected to a hydraulic circuit of the screed for this purpose, the piston carrying a shaft that can be pushed through the respective push-through opening and that is or can be provided with an abutment element this carries.

As a result of the attachment using spring-loaded cylinders, the time required for installing a screed extension part is significantly reduced and requires less effort, since the screed extension part can only be hooked into the screed when the spring-loaded cylinder is released and then connected to the screed by subsequently venting the spring-loaded cylinder.

In particular, the spring-loaded cylinders for supplying pressurized oil can be connectable to the oil supply to a leveling cylinder from two screed halves which can be pivoted relative to one another or, if appropriate, to a hydraulic cylinder for extending an extendable screed which is extendable relative to a base screed. As a result, an already existing hydraulic circuit of the screed can be used become.

A distributor head is preferably already preassembled on the relevant side wall of the screed extension part and is coupled to each of the spring-loaded cylinders via hydraulic lines. This further reduces the assembly time.

Further embodiments of the invention can be found in the following description and the subclaims.

• Fig. 1 zeigt eine Seitenansicht einer Einbaubohle für einen Straßenfertiger.
• Fig. 2 zeigt eine rückseitige Teilansicht der Einbaubohle von Fig. 1 mit angebauten Bohlenverlängerungsteilen.
• Fig. 3 zeigt vergrößert einen Ausschnitt von Fig. 2.
• Fig. 4 zeigt den Ausschnitt von Fig. 3 in Draufsicht.
• Fig. 5 zeigt ausschnittweise eine rückseitige Ansicht einer Einbaubohle mit beidseitig angebauten Bohlenverlängerungsteilen.

The invention is explained below with reference to an embodiment shown in the accompanying figures.

• Fig. 1 shows a side view of a screed for a paver.
• Fig. 2 shows a rear partial view of the screed of Fig. 1 with attached screed extension parts.
• FIG. 3 shows an enlarged detail from FIG. 2.
• Fig. 4 shows the detail of Fig. 3 in plan view.
• 5 shows a section of a rear view of a screed with screed extension parts attached on both sides.

The screed for a paver shown in FIGS. 1 and 2 expediently comprises two screed halves 1a, 1b (only one 1b of which is shown), which can be pivoted relative to one another and, if necessary, extended to form a roof profile transversely to the direction of installation.

Each screed half 1a, 1b further comprises an outer side wall 2 and a base plate 3. In the installation direction directly in front of the base plate 3, a tamper bar 4 extending transversely to the installation direction is arranged over the entire width of the base plate 3. The tamper bar 4 can be driven up and down by an adjustable stroke, for example, via an eccentric drive (not shown). The tamper bar 4 has an inlet slope 5 on its front edge. The angle of the inlet slope 5 is preferably between 30 ° and 70 ° in order to ensure an optimal supply of material to be installed.

Alternatively, the screed can also have two tamper strips 4 arranged one behind the other in the installation direction, as a pure one Vibrating screed or be provided with pressure bars.

The screed half 1 a, 1 b also has a front wall 6 on the side located on a distributor screw of the road paver feeding the material to be installed. The front wall 6 comprises a lower guide section 7 which is inclined to the tamper bar 4 and ends adjacent thereto. The angle of inclination of the guide section 7 suitably corresponds approximately to the angle of the run-in slope 5 of the tamper bar 4.

According to the embodiment shown in Figs. 1 and 2 in the side wall 2 on the side to be extended e.g. four through openings 8 are provided at the corners of a square for releasably attaching a screed extension part 9 to the screed half 1b. As also shown in FIG. 2 by views of the push-through openings 8 folded into the image plane and in FIG. 4, these are keyhole-like. The screed extension part 9 has, adjacent to the side wall 2 of the screed half 1 b, a side wall 10 with bores 11 at positions which correspond to the push-through openings 8 of the adjacent right side wall 2 of the screed half 1 b. In a side wall 12 of the screed extension part 9 opposite the side wall 10, push-through openings 13 corresponding to the push-through openings 8 in the side wall 2 are preferably provided.

Spring-loaded cylinders 14 are attached to the side wall 10 (shown enlarged in FIG. 3), each of which has a piston 15, which is spring-biased into its starting position by a compression spring 16 designed as a plate spring assembly and carries a shaft 17 which extends through the associated bore 11 extends in the side wall 10 and is provided at its end facing away from the piston 15 with an abutment element 18. The abutment element 18 preferably comprises a spring ring 19 plugged onto the shaft 17 and a nut 20 screwed onto the shaft 17. Each of the spring-loaded cylinders 14 further comprises, at its end remote from the nut 20, a connection opening 21 for a hydraulic line 22, via which the spring-loaded cylinder 14 leads to Displacement of the piston 15 against the spring force can be acted upon hydraulically for ventilation. For hydraulic loading, the hydraulic lines 22 can be connected to a hydraulic circuit, for example to a distributor head 23 of a hydraulic cylinder 24 serving for the oil supply, for adjusting the screed (here the extension cylinder for extending an extension screed 1 'of the screed half 1b) can be connected.

The push-through opening 8 is sufficiently large in its upper section 8a so that the abutment element 18 can be pushed through, and its lower section 8b is a little wider than the diameter of the shaft 17. When the spring-loaded cylinders 14 are released as a result of hydraulic action, the screed extension part 9 can therefore slide into the side wall 2 of the screed half 1b, the shaft 17 being received in the lower section 8b of the push-through opening 8 concerned.

Preferably, two adjusting screws 25 for height leveling are provided on the side wall 10 one behind the other in the installation direction and are supported on the upper edge of the side wall 2. When the screed extension part 9 is suspended and the spring-loaded cylinder 14 is lifted, the screed extension part 9 can first be leveled with the screed half 1b with respect to the base plate 3 by actuating the adjusting screws 25. Then, by venting the spring-loaded cylinders 14, the screed extension part 9 is clamped to the screed half 1b, the clamping being releasable again by venting the spring-loaded cylinders 14.

The screed extended in this way can additionally be extended in the same way with one or more further screed extension parts 26, which also have a side wall 27 with bores 28 at positions which correspond to those of the push-through openings 13 in the side wall 12 of the screed extension part 9.

If the screed half 1a, 1b comprises an extension screed 1 'in addition to a base screed, as shown in FIG. 2, the spring-loaded cylinders 14 can be connected to the oil supply of the hydraulic cylinder 24 for the extension screed 1', cf. Fig. 2. The spring-loaded cylinders 14 are preferably over a Existing outside steering position 29 of the screed can be controlled. For coupling to the hydraulic cylinder 24 located in the hydraulic circuit of the screed, the distributor head 23 is preassembled on the relevant side wall 2, 12 of the screed extension parts 9, 26 according to FIG. 1. The distributor head 23 is coupled to each of the spring-loaded cylinders 14 via the hydraulic lines 22 and can be connected to the hydraulic cylinder 24 via a hydraulic hose 30.

According to FIG. 5, plank extension parts 9 are attached to both (not extendable) plank halves 1a, 1b and each is additionally extended with further plank extension parts 26 (only partially shown on the right-hand side in FIG. 5). A leveling cylinder 31 coupled to both screed halves 1a, 1b serves to pivot the screed halves 1a, 1b against each other to form a roof profile. For the hydraulic loading of the spring-loaded cylinders 14, these can in particular be connectable to the oil supply to the leveling cylinder 31 of the screed.

Instead of the spring ring 19, a fork piece plugged onto the shaft 17 can also be used, which, however, should be secured to the shaft 17 by means of a chain or the like.

Claims (8)

1. Screed for a paver with two external side walls (2, 12) in which in at least one of the side walls (2, 12) through-openings (8, 13) are provided for the removable attachment of at least one lateral screed extension part (9, 26) by means of fastening elements, which can be inserted through the through-holes (8, 13), characterised in that the fastening elements include spring-loaded cylinders (14), which each comprise a piston (15) spring-biased in its initial position, can be hydraulically actuated to displace the piston (15) counter to the spring bias and to this end can be connected to a hydraulic circuit of the screed, whereby the piston (15) bears a shank (17) which can be inserted through the respective through-hole (8, 13), said shank being optionally provided with an abutment element (18).
2. Screed according to claim 1, characterised in that the spring-loaded cylinders (14) can be connected to the oil supply of a levelling cylinder (31) of two screed halves (1a, 1b) which are pivotable with respect to each other.
3. Screed according to claim 1, characterised in that the spring-loaded cylinders (14) can be connected to a hydraulic cylinder (24) to extend an extension screed (1') which is extendable with respect to a basic screed.
4. Screed according to one of claims 1 to 3, characterised in that the pressurised oil supply to the spring-loaded cylinders (14) can be controlled via an external control console (29) of the screed.
5. Screed according to one of claims 1 to 4, characterised in that on at least one side wall (2, 12) of the screed, a distributor head (23) is premounted, which is coupled via hydraulic lines (22) with each of the spring-loaded cylinders (14).
6. Screed according to one of claims 1 to 5, characterised in that the through-holes (8, 13) in the at least one side wall (2, 12) of the screed are keyhole shaped with an upper section (8a) to allow for penetration of the abutment element (18).
7. Screed according to one of claims 1 to 6, characterised in that the abutment element (18) includes a nut (20) and a split washer (19).
8. Screed according to one of claims 1 to 7, characterised in that the screed extension part (9, 26) bears two adjustment screws (25) supporting on the side wall (2, 12) of the screed to level the screed extension part (9, 26) with the screed part (1a, 1 b, 1') to be lengthened.