DEVICE FOR DRIVING A FLEXIBLE LANCE

Abstract

A device for driving a flexible lance for cleaning a heat exchanger duct or the like, includes a frame in which a driving mechanism is arranged for moving this flexible lance in a driving direction in the direction of an outlet opening. The driving mechanism is provided with a clamp member which can be clamped on the flexible lance and which is movable in the frame towards and away from this outlet opening. The clamp member is mounted on an endless drive element. The active part of the endless drive runs parallel to the driving direction. The drive mechanism further comprises at least one non-driven counter roller arranged opposite said clamp member. The lance is clamped between the clamp member and the counter roller.

Claims

1. A device for driving a flexible lance for cleaning a heat exchanger duct or the like, comprising: a frame in which a driving mechanism is arranged for moving the flexible lance in a driving direction which is in a direction of an outlet opening, wherein the driving mechanism is provided with a clamp member which is clampable on the flexible lance and which is movable in the frame towards and away from the outlet opening, wherein said clamp member is mounted on an endless drive element, wherein an active part of the endless drive element runs parallel to the driving direction, wherein the driving mechanism further comprises at least one non-driven counter roller arranged opposite said clamp member, and wherein the flexible lance is clamped between the clamp member and the non-driven counter roller.

2. The device for driving a flexible lance according to claim 1, wherein the non-driven counter roller is biased in a direction towards the clamping element for clamping the flexible lance there between.

3. The device for driving a flexible lance according to claim 1, wherein the driving mechanism is provided with a plurality of counter rollers, wherein the rotation axes of said counter rollers substantially extend in a plane parallel to said driving direction.

4. The device according to claim 3, wherein the plurality of counter rollers is arranged on a separate counter roller frame mounted in the frame, wherein the counter roller frame is movable with respect to said frame, and wherein the counter roller frame is biased in the frame.

5. The device for driving a flexible lance according to claim 3, wherein at least two of the counter rollers are movable with respect to each other in a direction towards and away from the lance to be driven.

6. The device for driving a flexible lance according to claim 5, wherein at least two counter rollers are arranged on a subframe, wherein the subframe is arranged for pivotally allowing relative movement of the counter rollers.

7. The device for driving a flexible lance according to claim 6, wherein the subframe is pivotally arranged in the counter roller frame.

8. The device for driving a flexible lance according to claim 1, wherein the endless drive element comprises a plurality of separate clamp members arranged along the length thereof.

9. The device for driving a flexible lance according to claim 8, wherein the clamp members are arranged to pivotally connect to the endless drive element.

10. The device for driving a flexible lance according to claim 9, wherein the clamp members are arranged at mutual distances on the endless drive element along the length thereof.

11. The device for driving a flexible lance according to claim 9, wherein a counter roller is located near an end of the active part of the endless drive element.

12. The device for driving a flexible lance according to claim 11, wherein counter rollers are located at both ends of the active parts of the endless drive element.

13. The device for driving a flexible lance according to claim 8, wherein one of said plurality of separate clamp members comprises a base member arranged to connect to the endless drive element, wherein the base member holds a plastic engaging member.

14. The device for driving a flexible lance according to claim 0, wherein the base member is substantially U-shaped, wherein the engaging member is received between the legs of the U-shape.

15. The device for driving a flexible lance according to claim 1, wherein the clamp member is provided with an engaging surface at least partially formed complementary to the lance to be engaged.

16. The device for driving a flexible lance according to claim 15, wherein the clamp member includes a V-shaped slot.

17. The device for driving a flexible lance according to claim 15, wherein the counter roller is arranged to substantially engage the engaging surface of the clamp member when no lance is supplied to the drive system, such that the distance between the axis of the counter roller and upper end of the clamp member on the active path, which is in contact with the counter roller, is equal or less then the radius of the counter roller.

18. An endless drive element provided with clamp members for use in device according to claim 1.

Description

[0025] The present invention is further illustrated by the following Figures, which show a preferred embodiment of the device according to the invention, and are not intended to limit the scope of the invention in any way, wherein:

[0026] FIG. 1 is a perspective view of the device according to a preferred embodiment;

[0027] FIG. 2 is a partly broken away perspective view of the same device as in FIG. 1;

[0028] FIG. 3 is a schematic view of the same device as shown in FIG. 1;

[0029] FIG. 4 shows schematically a part of the drive system of the device in the plane parallel to the driving direction;

[0030] FIG. 5 shows schematically a part of the drive system of the device in the plane perpendicular to the driving direction;

[0031] FIG. 6 shows further details of the active part of the endless drive element in operation in the plane parallel to the driving direction; and

[0032] FIGS. 7 and 8 show other examples of counter roller frame configurations.

[0033] FIG. 1 shows a driving device 1 for flexible lances according to the invention. The device comprises in- and outlets 5 for the flexible lance 11, see also FIG. 3. The lance 11 is to be driven in the direction between the in- and outlets 5. The driving device 1 comprises a driving unit 2, in particular a pneumatic motor, for driving the device 1, which is mounted to a frame 3. The frame 3 supports a counter-roller frame 4 and the counter roller frame 4 supports a plurality of counter rollers 8 which are arranged to roll on, preferably non-driven, on the lance 11. Opposite the counter rollers 8 is an endless drive element in the form of a chain 13 which is provided with a plurality of clamp members 12. The driving unit 2 drives the chain 13, thereby driving a lance 11 held between the clamp members 12 on the chain 13 and the counter rollers 8.

[0034] The counter roller frame 4 basically comprises two plate members 42 interconnected by a beam or bolt 43. The ends 41 of the plates 42 are received in slots 31. The counter roller frame 4 is thus movable with respect to the frame 3 in the vertical direction, indicated with I in the figures. In this vertical direction, the counter roller frame 4, and therewith the counter rollers 8, is urged towards the clamp members the frame 3, more specifically towards the clamp members 12 supported therein. An urging system 9 is hereto provided, which is in this embodiment formed by a nut-like element 92 on a treaded rod 91 and a compressed elastic element (not shown).

[0035] In FIG. 2 the driving device 1 is shown in a partly broken away perspective view, thereby showing the counter roller frame 4 in greater detail, which preferably comprises at least one subframe 6, which is connected to the counter roller frame 4 through the subframe pivot axis 7. The counter rollers 9 are hereby movable with respect to each other in in a direction having a component in the direction indicated with I.

[0036] In FIGS. 3 and 4 a schematic view of the driving system 10, including a flexible lance 11, is shown. As said, the driving system 10 comprises counter rollers 8, the clamp members 12 and an endless drive element 13 onto which the clamp members 12 are arranged. The counter rollers 8, which are urged onto the flexible lance 11 by the urging systems 9, ensure a good traction between the flexible lance 11 and the clamp members 12.

[0037] In FIGS. 5A and 5B the drive system 10 is shown in a plane perpendicular to the driving direction. The clamp members 12, which are formed in this embodiment from a base member 51 and a V-shaped engagement member 52, are suited for engaging flexible lances 11 of different diameters. In addition, the width of the counter rollers 8 is such that the counter rollers 8 are suited to engage the engagement members 52 when no flexible lance 11 is provided, while not engaging the inner surfaces 53 of the side walls of the base members 51. The width of the counter rollers 8 is thus smaller than the distance between the legs of U-shaped base member 3.

[0038] With reference to for instance FIG. 4, it can be seen that the clamp members 12 are arranged at mutual distances with respect to each other. The lance 11 is thus engaged intermittently, i.e. not along a surface along its length. This distances further allow pivoting of the clamp members 12 with respect to the surface of the lance 11 to be driven, indicated with the arrows II in FIG. 4. This pivoted or tilted configuration of the clamp members 12 is shown schematically in FIG. 6, which shows the active part 14 of the endless drive element 13. The forces exerted on the clamp members 12, at the lower end of the clamp members 12 by the endless drive element 13 and at the upper end of the clamp members 12 by the flexible lance 11, tilt the clamp members 12 around the axis parallel to the rotation axis of the counter rollers 8. Due to this tilting, areas of high contact pressure 61 are formed on the engagement surfaces of the tilted clamp members 12. Reference is also made to FIG. 2, wherein for one clamp member 12 this contact point(s) or contact line 61 is indicated. In this embodiment, counter rollers 8 are at least located near the end of the active part 14 of the endless drive element, thereby areas of high contact pressure 61 are formed on the clamp members 12 at both ends of the active part 14 of the endless drive element 13.

[0039] A second embodiment of the counter roller frame 4 is shown in FIG. 7. In this embodiment the sub frames 6 comprising the counter rollers 8, are connected to a major subframe 70 through the subframe pivot axes 7. The major subframe 70 is connected to the counter roller frame 4 through the major subframe pivot axis 71, thereby forming a wippletree mechanism. The construction of the counter roller frame 4 according to this second embodiment ensures a more evenly distribution of the urging load to the flexible lance 11 and the clamp members 12, thereby resulting in a better traction between the flexible lance 11 and the clamp members 12.

[0040] FIG. 8 shows another variant of the counter roller frame in different parts. Counter rollers 8 are provided, preferably in sets of two, at mutual distances on subframes 6, which have a triangular shape in this example. The lower corners receive the axes of two counter rollers 8, the top corner is provided with a pivot axis 61 connecting the sub frame pivotally to a frame 70a, 70b. Frame 70a carries two subframes 6, major sub frame 70a caries one sub frame 6 at one, each sub frame at a pivot axis 71, end and the minor frame 70a at the other end at pivot axis 71a. It may be possible that another minor frame 70a is connected to the other end of the major axis 70b. Provided at a central location between the counter rollers 8, is a central pivot axis 71b with which the system as shown is connected to the frame 4. The system is arranged such that a force F1 exerted on axis 71b is distributed evenly over the counter rollers 8, indicated with the arrows F2.

[0041] In this example, the pivot axes 61 of the subframes 6 are arranged at equal distances. The frames 70a, b are shaped such that an even load can be applied by the counter rollers 8. The central pivot axis 71b is preferably also arranged accordingly to this end.

[0042] The present invention is not limited to the embodiment shown, but extends also to other embodiments falling within the scope of the appended claims.