GB2341343A

GB2341343A - Butt welding machine for plastics pipes featuring clamps which are rotatable about the machine axis

Info

Publication number: GB2341343A
Application number: GB9919924A
Authority: GB
Inventors: Michael Basler; Horst Sluke; Wolfgang Hacker
Original assignee: Rothenberger Werkzeuge AG
Current assignee: Rothenberger Werkzeuge AG
Priority date: 1998-09-12
Filing date: 1999-08-24
Publication date: 2000-03-15
Also published as: GB9919924D0; DE19841812C1; ITMI991885A1; IT1313360B1; ITMI991885A0

Abstract

Butt welding machine for plastics pipes comprising a base frame 2 with two longitudinal side bars 3 and at least two clamps 15,16,17,18 which define a horizontal machine axis (A-A), having semi cylindrical inside surfaces and are displaceable relative and axis parallel to each other by means of horizontal guiding devices 14 and at least one drive 19, the clamps and guiding devices may be rotated, relative to the base frame, around the machine axis by the repositioning of a pair of C-shaped brackets 12 and 13 against a pair of frame mounted brackets. The C-shaped brackets 12, 13 may have partially ring shaped outer surfaces which can rotate smoothly over support elements on the brackets attached to the base frame 9, 10. The brackets may feature bores so that they may be joined together by bolts 11. The base frame may be provided with transport wheels 7 at one end of the machine. The machine may have spatially fixed clamps 15, 16 and movable clamps 17, 18 with parallel operating drives 19, 19a which can be electromechanical, pneumatic or hydraulic with connecting bends and pressure hoses 20, 21. The frame may include a protective plate 28.

Description

2341343 Butt Welding Machine for Plastic Pipes The invention relates to a

butt welding machine for plastic pipes comprising a base frame and at least two clamps which define a horizontal machine axis, have sernicylindrical inside surfaces and are displaceable relative and axis-parallel to each other by means of horizontal guiding devices and at least one drive.

Butt welding machines of this type are known through the catalogues of the applicants "ROTHENBERGER - die Kompetenz in Rohrtechnik ", 1994. In first forms of embodiment of type description P 160 B, P 250 B and P 315 B, the axes of the guiding devices and the separating joints of the clamps lie in a respective horizontal plane. In second forms of embodiment of type description P 500 B 2 and P 630 B 2, the axes of the guiding devices and the separating joints of the clamps lie in a respective plane inclined by 45 degrees. Both the one and also the other (unchangeable) spatial position of the separating joints lead in some applications to uncomfortable body positions of the operator as in most cases the machines have to be set up in or alongside ditches in which the pipelines are laid by welding together pipe sections.

This also requires a clearly broader ditch excavation, and earth excavation and refilling are costly processes.

It is therefore an object of the invention to offer a butt welding machine of the aforedescribed type which can be operated in an ergonomic position and which allows a reduction in volume of earth excavation when laying pipelines in a ditch.

The object is achieved according to the invention with the aforedescribed butt welding machine in that the guiding devices with the clamps are rotary around the machine axis relative to the base frame.

This solution ftilly achieves the object, i.e. welding work can be carried out in more comfortable body positions of the operator, and the volume of earth excavation is clearly reduced.

In the course of further embodiments of the object of the invention, it is particularly advantageous if, either individually or in combination, - the base frame comprises two longitudinal side bars which are joined together by two first traverses, when the guiding devices are joined together by second C-shaped traverses, and when the first and second traverses are rotary relative to each other around the machine axis (particularly stable frame construction against flexural loads by pipelines which protrude laterally by metres); - between the base frame and the second C-shaped traverses is configured a respective rotary guide, in particular if this can be fixed; - the C-shaped traverses have partially ringshaped outside surfaces, and when the first traverses are provided with support elements on which the outside surfaces of the second traverses can be glidingly rotated; - the first traverses of the base frame are provided with first bores parallel to the machine axis, when the second C-shaped traverses are on a part circle provided with a plurality of second bores which can be placed to coincide in different angular positions in pairs with the first bores in the first traverses, and when the first and the second bores can be joined together by bolts; the base frame comprises two longitudinal side bars the ends of which are on the other side of the C-shaped traverses provided with transport wheels (easier mobility); the lowest points of the transport wheels lie higher than the lower edge of the longitudinal side bars (defined position of the butt welding machine at work); - spatially fixed and movable clamps are provided in pairs, when two parallel operative drives with connecting bends and pressure hoses are located between a pair of clamps, and when the ends of the connecting bends facing away from the drives extend parallel to the clamp axis (reduction of the entire width dimensions and earth excavation; reduction of danger of damage to armatures); - the longitudinal side bars and the transport wheels are configUred between two vertical planes in which lie the farthest outward points of the C-shaped traverses (further reduction of the entire width dimensions and earth excavation); the longitudinal side bars are below the gap between the spatially fixed and the movable clamps joined together by a protective metal plate (minimising or keeping away foreign bodies from the welding area); the C-shaped traverses are jointly rotary by a synchronised adjustment device, in particular when the adjustment device is composed of a shaft with a drive element and two pinions which engage respective toothings on the C-shaped traverses (more precise alignment of the clamps when re- mounting).

An exemplary embodiment of the object of the invention will now be described in more detail, based on Figures 1 to 5.

Shown are, in Figure 1: a side view of the butt welding machine; Figure 2: a front view of the butt welding machine as in Figure 1 in an axis-parallel viewing direction, with the horizontal guiding devices lying in a horizontal plane; Figure 3: a front view of the butt welding machine analogue Figure 2, and the horizontal guiding devices lie in a plane which is rotated by 30 degrees; Figure 4: an axial top view of one of the pivotal C-shaped second traverses; and Figure 5: an axial top view of one of the first traverses connected to the base frame.

Figures 1 and 2 illustrate a butt welding machine 1 with machine axis A-A, comprising a ground frame 2 with two axis parallel longitudinal side bars 3. These are at their one end joined by an upward bent yoke 4, whilst the other upward bent end areas 5 are joined by an axis 6 which carries two transport wheels 7. If longitudinal side bars 3 are erected on a plane surface 8, then the lowest points of transport wheels 7 are at distance "s" from this surface. With yoke 4 lifted, the device can be moved in the manner of a wheelbarrow.

Furthermore, the two longitudinal side bars 3 are joined together by two welded on first traverses 9 and 10 to which are detachably mounted by means of bolts 11 second C-shaped traverses 12 and 13 the appearance of which is shown in the other figures, in particular Figure 4. The ends of these second traverses 12 and 13 are joined by two guiding devices 14 which are parallel to each other and to machine axis A-A and which support a total of four clamps 15, 16, 17 and 18. The two lefthand clamps 15 and 16 are spatially fixed in the axial direction, and the two righthand clamps 17 and 18 are displaceable parallel to the axis. For this purpose, two diametrically opposite drives 19 are provided, designed as double acting pressure cylinders and each having one piston (not illustrated) and two pressure pipe connections 21 and 20 designed as connecting bends the ends of which facing away from pressure cylinders 19 extend axis parallel, so that the bulkiness of the arrangement is reduced and danger of breakage excluded. Alternatively, a single electromechanical drive 19a can be provided which supports itself on the one side against traverse 13 and on the other side against clamp 18.

Between clamp pairs 15/16 and 17/18 is a variable gap "D" into which, for the purpose of preparing butt welding, a doublesided rotary planing tool (not illustrated) and a heating element (also not illustrated) can be inserted for plane-parallel processing of the ends of pipeline sections to be welded and subsequently bringing them up to welding temperature. However, these elements are part of the prior art so that further descriptions can be dispensed with. Clamps 15 to 18 have semi-cylindrical inside surfaces 22 and 23 and clamping spindles 18a, which is also prior knowledge and therefore not described in more detail.

First traverses 9 and 10 have near longitudinal side bars 3 support elements 24 on which second traverses 12 and 13 are seated and, after release of bolts 11, glidingly rotary around machine axis A-A. This is possible because C-shaped traverses 12 and 13 have concentrically to machine axis A-A partially ringshaped outside surface 25, which is particularly clearly shown in Figures 4 and 5. This establishes a respective rotary guide between base frame 2 and the second C-shaped traverses 12 and 13 which can be secured b,,, bolts 11.

Figures 4 and 5 show that the first traverses 9 and 10 of base frame 2 are provided with first bores 26 which run parallel to machine axis A-A, and the second Cshaped traverses 12 and 13 are provided with a plurality of second bores 27 on a concentric partial circle 'W' which in different angular positions coincide in pairs with first bores 26 in first traverses 9 and 10. The first and two of the second bores 26 and 27 can then be joined together by bolts 11. Furthermore, Figure 4 shows two points P 1 and P2 which are of significance in conjunction with a view of Figure 2.

Longitudinal side bars 3 and transport wheels 7 are configured between two vertical planes E l and E2 (Figure 2), in which lie the farthest outside points P I and P2 of the C-shaped traverses (Figure 4). This further reduces the total structural width as compared to conventional butt welding machines.

Longitudinal side bars 3 are joined together by a protective metal plate 28 below gap "D" between spatially fixed (15 and 16) and movable clamps 17 and 18. This offers the great advantage that objects protruding from the ground, such as plants, cannot enter the welding area and reduce the quality of the welding seam.

Figure 4 describes yet another possibility of embodiment of the invention, in that the C-shaped traverses 12 and 13 are jointly rotary by means of a synchronously working adjustment device 29. For this purpose, adjustment device 29 is composed of a shaft 30 with a (not illustrated) preferably arrestable drive (for example a lever or a hand wheel) and two pinions 31 which engage respective toothings 32 on C-shaped traverses 12 and 13.

The operational manner of butt welding machine 1 is described based on Figure 3 as follows: After release and removal of four bolts 11 from both C-shaped clamps 12 and 13, guiding devices 14 and with them all clamps 15 to 18 can be rotated around machine axis A by angle "a" of, for example, 30 degrees. Both C-shaped traverses 12 and 13 then glide with the partcylindrical outside surfaces 25 on support elements 24 until four other second bores 27 coincide with the four first bores 26. The assembly in the new position can again be arrested by screwing in and tightening of bolts 11. This makes it possible to place butt welding machine 1 into a most ergonomic position for the operator(s).

List of Reference Marks 1 Butt Welding Machine 2 Base Frame 3 Longitudinal Side Bar 4 Yoke End Areas 6 Axis 7 Transport Wheels 8 Plane Surface 9 Traverse - Traverse 11 - Bolts 12 - Traverse 13 - Traverse 14 - Guiding Devices - Clamp 16 - Clamp 17 - Clamp 18 - Clamp 18a - Clamp Spindles 19 Drives 19a - Electro-mechanical Drive - Pressure Pipe Connection 21 Pressure Pipe Connection 22 - Inside Surface 23 - Inside Surface 24 Support Element Outside Surfaces 26 - First Bores 27 - Second Bores 28 Protective Metal Plate 29 - Adjustment Device - Shaft 31 - Pinion 32 Toothing A, AA - Machine Axis D - Gap EI - Plane E2 - Plane K - Partial Circle PI - Point P2 - Point

Claims

Claims

Butt welding machine for plastic pipes, comprising a base frame (2) and at least two clamps (15, 16, 17, 18) which define a horizontal machine axis (A-A), have serni- cy lindri cal inside surfaces (22, 23) and are displaceable relative and axis-parallel to each other by means of horizontal guiding devices (14) and at least one drive (19, 19a), characterised in that the guiding devices (14) with the clamps (15, 16, 17, 18) are rotary around the machine axis (A-A) relative to the base frame (2).

2: Butt welding machine according to Claim 1, characterised in that the base frame (2) comprises two longitudinal side bars (3) which are joined together by two first traverses (9, 10), and the guiding devices (14) are joined together by second C-shaped traverses (12, 13), and the first and second traverses are rotary around the machine axis (A-A) relative to each other.

3: Butt welding machine according to Claim 2, characterised in that between the base frame (2) and the second C-shaped traverses (12, 13) is arranged a respective rotary guide.

4: Butt welding machine according to Claim 3, characterised in that the rotary guide can be fixed.

5: Butt welding machine according to Claim 2, characterised in that the C shaped traverses (12, 13) have partially ringshaped outer surfaces (25), and the first traverse (9, 10) are provided with support elements (24) on which the outside surfaces (25) of the traverses are glidingly rotary.

6: Butt welding machine according to Claim 5, characterised in that the first traverses (9, 10) of the base frame (2) are provided with first bores (26) which extend parallel to the machine axis (A-A), and the second C-shaped traverses (12, 13) are provided with a plurality of second bores (27), which are positioned on a partial circle (K) and which can coincide in different angular positions in pairs with the first bores (26) in the first traverses (9, 10), and the first and second bores (26, 27) can be joined together by bolts (11).

7: Butt welding machine according to Claim 1, characterised in that the base frame (2) comprises two longitudinal side bars (3) and end areas (5) of which are on the other side of the C-shaped traverses (12, 13) provided with transport wheels (7).

8: Butt welding machine according to Claim 7, characterised in that the lowest points of the transport wheels (7) lie higher than the bottom edges of the longitudinal side bars (3).

9: Butt welding machine according to Claim 1, characterised in that spatially fixed (15, 16) and movable clamps (17, 18) are provided in pairs, and between a pair of clamps (17, 18) are located two parallel operating drives (19) with connecting bends and pressure hoses, and the ends of the connecting bends facing away from the drives (19) extend parallel to the clamp axis (A-A).

10: Butt welding machine according to Claim 7, characterised in that the longitudinal side bars (3) and the transport wheels (7) are configured between two vertical planes (El, E2) in which lie the farthest outward points (P1, P2) of the C-shaped traverses (12, 13).

ll: Butt welding machine according to Claim 1, characterised in that the base frame (2) is below the gap (D) between the spatially fixed and the movable clamps (15, 16, 17, 18) joined together by a protective metal plate (28).

12: Butt welding machine according to Claim 1, characterised in that the C shaped traverses (12, 13) are jointly rotary by a synchronously operative adjustment device (29).

13: Butt welding machine according to Claim 12, characterised in that the adjustment device (29) comprises a shaft (30) with a drive and two pinions (3 1) which engage respective toothings (32) on the C-shaped traverses (12, 13).