EP0386008B1

EP0386008B1 - Motor-driven apparatus for manipulating valves

Info

Publication number: EP0386008B1
Application number: EP19880907426
Authority: EP
Inventors: Bertil Karlsson
Original assignee: Wilh Ruhberg AB
Current assignee: WILH. RUHBERG AB
Priority date: 1987-08-19
Filing date: 1988-08-12
Publication date: 1993-10-13
Anticipated expiration: 2008-08-12
Also published as: DK163969B; DK44190A; DE3884961T2; DE3884961D1; EP0386008A1; WO1989001390A1; SE462321B; DK163969C; DK44190D0; SE8703222L; SE8703222D0

Abstract

A portable motor-driven apparatus for manipulating valves of the kind which have screwthreaded valve spindles extending in wells or like conduits. The apparatus comprises an internal combustion motor (1) which is firmly mounted on a carrier frame. The motor drives a rod (15) which carries on one end thereof a tool (15) for turning the valve spindle. For the purpose of preventing relative rotation between the motor unit and respective wells or like conduits, the apparatus includes means (17) for temporarily connecting the motor unit with the well or like conduit. This means suitably has the form of a torsionally rigid tube (17) which surrounds the drive rod (15) and which is provided with a catch device (18) which fits the well opening.

Description

A portable motor-driven apparatus for manipulating valves of the kind having screwthreaded valve spindles which extend in wells or like conduits, said apparatus including an internal combustion motor firmly mounted on a carrier frame, a valve spindle rotating tool mounted on one end of a rod driven by said motor, and a torsionally rigid tube which at its one end is non-rotatably connected to the motor and which surrounds the drive rod.
Valves incorporated in the service conduits of municipal water networks and equivalent systems are at present normally opened and closed manually with the aid of a so-called T-spanner. Field measurements have shown that the torque required to manipulate the valves ranges from about 1500 to 400 Nm. Many valves are stiff to turn, or move sluggishly. Such stiffness is particularly experienced when closing valves which have remained open for long periods of time, the stiffness of the valve being due to the formation of iron-oxide fungus on the moveable valve components. This fungus will also prevent the valve from being closed in one single working step, and often necessitates the valve being opened and closed a number of times, so that the fungus is scraped off and flashed away. Only then can the valve be fully closed. The work required in this respect is physically hard and places great strain on primarily the elbows, shoulders and arms. Furthermore, the jerking forces engendered when a tight valve suddenly loosens can result in serious injuries.
In order to overcome these drawbacks, motor-driven apparatus or machines are to be found for manipulating valves of the aforesaid kind. Present day apparatus, however, can only be used to a limited extent, since they are operated either electrically or hydraulically and thus need to be connected to a service vehicle. Many of the valves in question, however, are located in so-called green areas, where they cannot be reached with a service vehicle, at least not without causing destruction of the surrounding vegetation, etc.
Simple, portable apparatus or machines driven by an internal combustion motor have also been proposed in the art. One drawback with the known apparatus of this kind, however, is that the motor unit is liable to rotate in relation to the well or conduit and consequently the whole of the torque generated is taken up by the operator. The operator can thus be subjected to heavy and abrupt jerking forces, even when using apparatus of this kind. Furthermore, since the apparatus as a whole is liable to rotate around the well or like conduit such apparatus represent a serious accident hazard. Another drawback with this particular kind of apparatus is that the operator is totally unaware of the amount of torque that is applied and consequently the threads of tight valves may be damaged as a result of the application of excessive torque.
WO-A-83/00368, which represents the weakest prior art, discloses a portable power drive means adapted to be connected to the handwheel shaft of larger size valve actuators. The drive means is non-rotatably secured to the valve actuator housing by means of bolts and clamps. This means that the drive means requires the valve actuator housing to be easily accessible which is not the case in connection with valve spindles which extend in wells or like conduits.
The main objects of the present invention are to provide a portable, motor-driven apparatus for the manipulation of valve spindles extending in wells or like conduits which apparatus eliminates the aforesaid injury and accident risks, and also to provide an apparatus which can be used in any selected location without being dependent on the presence of a service vehicle.
These objects are achieved with an apparatus as specified in the introductory paragraph in which the tool co-acting with the valve spindle is driven by an internal combustion motor, this apparatus being mainly characterized in that the torsionally rigid tube at its other end is provided with a catch device which surrounds the tube in a non-rotatably manner and is axially slideable along the tube, that the catch device can be non-rotatably connected to the well or like conduit by coaction with the inner, or with the inner and outer contours of the well or like conduit so as to prevent relative rotation between the motor unit and said well or like conduit, and that the torsionally rigid tube can be laterally displaced in one direction within the catch device.
The inventive apparatus thus eliminates the risks of injury and accidents that can occur as a result of heavy jerks and also the risk of the apparatus rotating. Further, it can be used for the manipulation of valves which are angulary displaced in relation to the valve spindle and/or wich are not located in the center of the well or like conduit.
The rigid element may conveniently be provided with catch means which fits in the well opening.
The apparatus preferably also includes means for detecting the torque between the motor unit and the means for preventing rotational motion, thereby eliminating, inter alia the risk of damage due to torn screwthreads.
The torque detector preferably comprises at least one hydraulic piston-cylinder device, or equivalent device, connected between the rotation-preventing means and the motor unit, and the apparatus may accordingly incorporate a gear mechanismus between the motor and the drive rod, said gear mechanism being controllable in accordance with the hydraulic pressure prevailing in the cylinder of said device. The gear mechanism will conveniently include a variator in which the mutual distance between the disks of a belt pulley of the variator is adjusted in dependence on the hydraulic pressure. This will afford an automatic gear change in accordance with the required torque.
Other features and characteristics of the invention will be apparent from the following claims.
The invention will now be described in more detail with reference to the accompanying drawings.
Figure 1 is a side view of valve manipulating apparatus according to the invention.
Figure 2 is a view taken on the line II-II in Figure 1, showing the apparatus applied in a well or like conduit.
Figure 3 is a view taken on the line III-III in Figure 2.
Figure 4 is a view taken on the line IV-IV in Figure 1, rotated through 90°.
Figure 5 is a view taken on the line V-V in Figure 4.
The apparatus illustrated in Figure 1 includes an internal combustion motor 1 having a manual starting device 2. The apparatus is carried by means of a handle 3 which surrounds the motor 1 and which is constructed to dampen occurrent vibrations. The surrounding handle also forms an effective device for protecting the motor and associated components, e.g., during transportation of the apparatus. The apparatus may advantageously also be fitted with a carrier harness, not shown.
The motor 1 is preferably a high-speed motor and one which, subsequent to gear reduction is able to generate the requisite torque despite its small dimensions and low weight. The speed of the motor is regulated with the aid of a throttle lever 4 mounted on the handle 3.
The output shaft of the motor 1 is connected, via a centrifugal clutch 5 to a variator mechanism 2 comprising two belt pulleys 6 and 7, the disks of which can be displaced relative to one another in order to vary the gear ratio in a known manner. The reference 8 identifies a belt extending between the pulleys. The disks of the pulley 6 are biassed towards one another with the aid of a spring 9, whereas the distance between the disks of the pulleys 7 can be adjusted with the aid of a hydraulic piston-cylinder device 10.
The pulley 7 drives a shaft 11 which is connected to an output rod 15 via a reversible gear 12, which can be adjusted with the aid of an auxiliary device 13, and angle gear 14. The rod 15 carries at its lower end a tool 16 intended for driving a valve spindle in one or the other direction.
In order to ensure that the operator will not need to take-up the torque required to operate a valve, the illustrated apparatus is provided with a tortionally rigid square-section tube 17 which surrounds the rod 15 and which connects the motor unit with the well or like conduit in question, such as to prevent relative rotation between the motor unit and said well or like conduit. To this end, the lower end of the tube 17 is surrounded by a catch device 18 which is arranged non-rotatably in relation to the tube and which is intended to be non-rotatable connected to a well or like conduit when introduced thereinto. In this regard, the catch device 18 is displaceablealong the tube 17, so as to enable valve spindles located at different depths to be reached.
Figures 2 and 3 illustrate schematically a well 19 provided with an inner support flange 20 which surrounds a substantially square opening 21. The catch device 18 is inserted through this opening, said device including an inner tube 22 which fits closely around the square tube 17 at two opposing sides while leaving a relatively large clearance on the other two sides. This enables the square-section tube 17 to be displaced laterally in relation to the tube 22, so that the rod 15 can be connected to a valve spindle even when said spindle is not centered in the well, see the chain-line circles in Figure 2. This will also enable the rod 15 to be angled relative to the valve spindle should the spindle be inclined to the vertical.
The inner tube 22 is axially moveable but not rotatable in an outer tube 23, which is provided with an upper flange 24 which is intended to abut the support flange 20 of the well and which is a relatively close fit in the well opening 21, so as to enable the transmission of torque from the square-section tube 17 to the well. In this case, the tubes 17, 22 and 23 will be rotated slightly in relation to the well opening 21, as illustrated in Figure 2. The same dimensioned tube 23 can therewith be used in wells whose dimensions vary within given limits.
As illustrated in Figure 1, the lower end of the torsionally rigid tube 17 has provided thereon a number of shoulders 25 for retaining the catch device 18 on said tube. The tube 22 is also provided with upper and lower stop shoulders 26 and 27, for restricting movement of the tube 22 relative to the tube 23. Because the tube 22 can be moved axially relative to the tube 23, it is possible to transmit torque to a well even when manipulating a valve spindle which is placed at a shallow depth in the well.
Figures 4 and 5 illustrate the manner in which a torsionally rigid tube 17 is coupled to the motor unit. The reference 28 identifies a plate bolted to the motor unit. The plate 28 has provided therein an opening which accommodates the rod 15 and which is partially filled with a ring 29 made of synthetic material, to permit rotational movement between the plate and the rod 15. A lever 30 is welded to the rotationally rigid tube 17 at a location beneath the plate 28. The arm 30 extends in between the piston rods 31 and 32 projecting from respective hydraulic piston- cylinder devices 33 and 34. The piston-cylinder devices are firmly connected to the plate 28, and each incorporate a thrust spring 36 which acts on respective piston rods 31 and 32. The piston- cylinder devices 33 and 34 are connected to a common hydraulic pipe 39 by means of respective hydraulic pipes 37 and 38, said hydraulic pipe 39 extending to the cylinder 10 intended for operating the pulley 7, see Figure 1. A branch pipe 40 conducts pressure oil to a manometer 41.
The manner in which the apparatus described with reference to Figures 4 and 5 operates will now be described. When the apparatus is at rest, or in its starting position, the pistons 35 of the two piston- cylinder devices 33 and 34 are held in their outer terminal positions by the action of respective springs 36, the lever 30 being in a centered position. When a valve is opened or closed, by rotating the rod 15 in one or the other direction, torque is generated in an opposite direction between the motor unit and the torsionally rigid tube 17 connected to the well. This causes the piston 35 of one piston- cylinder device 33 or 34 to be pressed into its associated cylinder against the action of the spring provided therein while increasing the hydraulic pressure. The other piston rod will remain in its outer terminal position.
This increase of the oil pressure in the cylinder indicates the prevailing torque, and the pressure is transmitted through the pipe 39 to the piston of the piston-cylinder device 10, which adjusts the pulley 7 to produce a suitable transmission in response to the torque indicated, see Figure 1. When the rod 15 is rotated about its longitudinal axis in the opposite direction, the piston of the other piston-cylinder device will be pressed into its cylinder and supply the piston-cylinder device 10 with oil at a pressure corresponding to the prevailing torque. Thus, in this way, there is obtained an automatic gear change corresponding to the requisite torque.
Reversal of the direction of rotation is effected simply by extending or withdrawing the auxiliary device 13, which determines which of the conical gears on the horizontal shaft of the reversable gear 12 shall be coupled to the conical gear on input shaft 11.
The pressure delivered by respective hydraulic piston- cylinder devices 33 and 34 is also applied to the manometer 41 which may be graduated in a manner to enable the prevailing torque to be read off. This enables the operator to see immediately the torque generated by the apparatus at any given moment, thereby greatly reducing the risk of damaging a valve as a result of excessively high torque. The manometer may also be provided with signs representing different types of valves. Other indicating devices may be used instead of a manometer, such as light emitting diodes which are activated in response to hydraulic pressure, each diode representing the maximum value for a particular type of valve.
The volume of oil in respective hydraulic piston- cylinder devices 33 and 34 is so large as to prevent bottoming of respective pistons, and consequently the oil pressure delivered will always represent the prevailing torque.
The use of a gear transmission arrangement according to the invention provides an apparatus which is capable of turning the valve spindle very rapidly at low torques and which can be stepped down to provide the requisite torque for loosening and tightening a valve. In the case of one tested embodiment of the invention, which afforded good results, the gear ratio was such that the valve spindle could be turned at a speed of 26 rpm at low torques and at a speed of 7 rpm when loosening and tightening the valve. The maximum torque for valve types of the kind in question normally lies within the range of 150-400 Nm. The primary speed of the motor was in the order of 7000 rpm.
A preferred embodiment of the inventive apparatus has been described above with reference to the accompanying drawings. It will be understood, however, that modifications can be made to the illustrated embodiment without departing from the scope of the following claims. For example, the two hydraulic piston-cylinder devices of the described embodiment can be replaced with a single piston-cylinder device which is constructed for detecting torque in both one and the other directions of rotation. The catch device may also be modified in a suitable manner, depending upon the configuration of the well or like conduit. This alternative catch means may be constructed for co-action with the outer contours of the well in addition to the interior thereof. The variator may also be replaced with some other kind of automatically actuable gear change device. In this case, torque detection can be effected in some other suitable manner.

Claims

A portable motor-driven apparatus for manipulating valves of the kind having screwthread valve spindles which extend in wells or like conduits, said apparatus including an internal combustion motor (1) firmly mounted on a carrier frame, a valve spindle rotation tool (16) mounted on one end of a rod (15) driven by said motor, and a torsionally rigid tube (17) which at its one end is non-rotatably connected to the motor and which surrounds the drive rod (15), characterized in that the torsionally rigid tube (17) at its other end is provided with a catch device (18) which surrounds the tube (17) in a non-rotatably manner and is axially slideable along the tube, that the catch device (18) can be non-rotatably connected to the well or like conduit by coaction with the inner, or with the inner and outer contours of the well or like conduit so as to prevent relative rotation between the motor unit and said well or like conduit, and that the torsionally rigid tube (17) can be laterally displaced in one direction within the catch device (18).
Apparatus according to Claim 1, characterized in that the catch device (18) fits non-rotatably in the well opening (21).
Apparatus according to Claim 1 or 2, characterized in that it further includes means (30, 33, 34) for detecting the torque prevailing between the motor unit and said rotation-preventing means (17, 18).
Apparatus according to Claim 3, characterized in that the torque detecting means includes at least one hydraulic piston-cylinder device (33; 34) or a corresponding device connected between the motor unit and the rotation-preventing means (17, 18); and that the apparatus further includes a gear transmission (6, 7) between the motor (1) and the drive rod (15), said gear transmission being controlled in response to the hydraulic pressure in said at least one piston-cylinder device.
Apparatus according to Claim 4, characterized in that the gear transmission includes a variator in which the mutual distance between the disks of a pulley (7) of the variator is adjusted in response to the hydraulic pressure.
Apparatus according to Claim 4 or Claim 5, characterized by means (41) for detecting the hydraulic pressure for the purpose of indicating the torque prevailing on the valve spindle.
Apparatus according to Claim 5 or Claim 6, characterized in that the apparatus further includes a centrifugal clutch (5) connected between the motor (1) and the variator (6, 7).
Apparatus according to any of Claims 1-7, characterized in that the apparatus further includes a reversable gear (12) connected between the motor (1) and the drive rod (15).