FIELD OF THE INVENTION

This invention relates to inspection and repair of elevated pipes, cable racks and the like on industrial sites such as, for example, refineries, petrochemical and metallurgical plants. In essence, the invention focuses on selective lifting and lowering of heavy objects for relatively short distances. More specifically, the invention relates to a lifter and a method of using same.

BACKGROUND TO THE INVENTION

A variety of devices are known and used nowadays to selectively lift and lower heavy objects, relative to a specific position. However, not all lifting and lowering devices are equally suitable for lifting cable racks, piping and elevated structures.

Where elevated piping, cable racks, or supports therefor, require corrosion protection, painting, welding, cable placement and other maintenance or inspection activities, cranes with riggers and operators, jack systems, chainfalls and branded jacks are often utilized to assist with lifting and lowering operations. While all of the abovementioned devices are capable of achieving selective lifting or lowering of the heavy elevated piping, cable racks, or supports therefor; not all are equally effective, safe and user friendly.

A common shortcoming of the known lifting devices is the inability thereof to lift and lower elongate objects where space between such objects is limited. This problem is more prevalent on industrial plants and the like where piping, through which live fluid is transferred, are spaced relatively close to each other. The distance between adjacent pipe axes may vary. In these conditions, known lifting devices fail to provide an effective, safe and user-friendly solution for lifting live narrowly spaced apart piping. It is believed that the lifter of this invention and its associated method of use address shortcomings in the abovementioned prior art systems and provide a safe solution to a long-felt need in industry.

SUMMARY OF THE INVENTION

In accordance with this invention there is provided a lifter for selectively raising and lowering a structure having a longitudinally extending axis to and from a predetermined position relative to a support having a longitudinal extent, the lifter comprising: a pair of arms having upper portions and lower portions, wherein said lower portions of said pair of arms are pivotally connectable to said support, and wherein said pair of arms are longitudinally spaced apart so as to define a space therebetween within which the support may be disposed in a transverse manner with respect to said longitudinal extent of said support, and wherein said pair of arms are axially aligned with said longitudinally extending axis while extending upwardly at predetermined angles with respect to said support; a pair of support members, each extending perpendicular to said longitudinally extending axis of said structure, for fixedly mounting upon central portions of said pair of arms so as to support said structure disposed transversely with respect to said pair of support members; and retractable and extensible mechanisms operatively connected to upper portions of each one of said arms such that as said retractable and extensible mechanisms are retracted, said upper portions of each arm is drawn together so as to cause each arm to pivotally move around said lower portions of said arms relative to said support structure and thereby elevate said pair of support members so as to, in turn, elevate the structure supported upon said support members, whereas when said retractable and extensible mechanisms are extended, said upper portions of each one of said arms are moved apart from each other so as to cause each one of said arms to pivotally move said lower portions of said arms relative to said support and thereby lower said support members so as to, in turn, lower said structure supported upon said support members. In an embodiment, each arm may comprise two limbs facing each other for flanking lateral sides of said structure, in use. A lower portion of each limb may comprise a pivot for movable connection of said pair of arms to opposing lateral sides of said support.

The invention may further provide for each of said limbs to be formed from sheet material to ensure the width of each limb is limited thereby to facilitate positioning of said lifter in areas where tight spaces are defined between longitudinally extending axis of adjacent structures to be raised or lowered. The sheet material may comprise a metal alloy having a high strength to mass ratio.

In an embodiment of the invention, the lifter may comprise a positioning bracket having a cross-member flanked by two laterally spaced apart legs, said cross-member being connectable to said support such that a lower end of each of said legs movably accommodates each of said pivots respectively.

In an embodiment of the invention, each one of said retractable and extensible mechanisms may comprise a hydraulically actuated piston displaceably located within a cylinder such that said piston is operably permitted to move rectilinearly within said cylinder upon actuation thereof so as to thereby selectively displace said upper portions of said pair of arms toward and away from each other.

In an embodiment of the invention, the lifter may comprise a pair of elongate rods respectively extending linearly above said retractable and extensible mechanisms wherein each one of said pair of elongate rods has a threaded outer surface to which lock-out nuts are provided such that oppositely disposed ends of said elongate rods can be locked out when said arms reach a predetermined angle corresponding to predeterminedly desired elevation levels of said support members.

In an embodiment of the invention, each one of said pivots may comprise a protuberant formation configured to bear against and prop said lower portions of said arms against an outer surface of each of said laterally spaced apart legs of said positioning bracket.

In an embodiment of the invention, said limbs may be identically shaped and configured. An aperture through which said support member can extend, may be defined in a central portion of each of said limbs. Said central portions of said limbs may be bent at an angle of between 100° and 130° so as to thereby permit upward movement of said support members when said retractable and extensible mechanisms are actuated.

The invention extends to a method for selectively raising and lowering a structure to and from a predetermined position relative to a support, comprising the steps of:

providing a support;

providing a lifter for bestriding said structure,

wherein said lifter comprises a pair of arms having upper portions and lower portions at which a pivot is defined, each arm comprising two limbs facing each other;

longitudinally spacing said pair of arms apart from each other with respective limbs flanking lateral sides of said structure and movably connecting said pivots to said support, wherein and said pair of arms is being adapted to be longitudinally spaced apart and axially aligned with an elongate axis of said structure while extending upwardly at predetermined angles with respect to said support;

fixedly mounting a pair of longitudinally extending support members upon central portions of said pair of arms so as to support said structure disposed transversely with respect to said pair of support members; and

operatively connecting retractable and extensible mechanisms to upper portions of each one of said pair of arms such that as said retractable and extensible mechanisms are retracted, said upper end portions of each one of said pair of arms are drawn together so as to cause each one of said pair of arms to pivotally move around said pivots of said arms relative to said support and thereby elevate said pair of support members so as to, in turn, elevate said structure supported upon said support members, whereas when said retractable and extensible mechanisms are extended, said upper portions of each one of said pair of arms are moved apart from each other so as to cause each one of said pair of arms to pivotally move said lower portions of said pair of arms relative to said support and thereby lower said pair of support members so as to, in turn, lower said structure supported upon said support members.

The method may comprise utilizing a positioning bracket securable to said support to movably accommodate and seat said pivots to said support.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are now described, by way of example, with reference to the accompanying non-limiting diagrammatic drawings. In the drawings:

Figure 1 shows an isometric view of a lifter according to an embodiment of the invention with the lifter being shown in its lowered configuration;

Figure 2 shows a front-end view of the lifter of Figure 1 ; and

Figure 3 shows a front-end view of the lifter of Figure 1 with the lifter being shown in its raised configuration.

DETAILED DESCRIPTION OF THE DRAWINGS

This description is presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how at least some of the several forms of the invention may be embodied in practice.

Referring to Figures 1 to 3, reference numeral 10 generally indicates a lifter in accordance with the invention.

Lifter 10 is believed to address a common shortcoming associated with known lifting devices for lifting heavy objects on industrial plants and the like where space between such objects is limited and especially where live feed flows through said objects. Often on industrial plants and the like where piping, through which live fluid is transferred, are spaced relatively close to each other, the distance between adjacent pipe axes are limited thus preventing use of known jack systems. The distance between such piping may, for example, range between 100mm to 150mm. In these conditions, known lifting devices fail to provide an effective, safe and user-friendly solution for lifting live narrowly spaced apart piping.

Referring to Figures 1 to 3 of the drawings, the lifter 10 is adapted for selective raising and lowering of a structure 12, such as a pipe, having a longitudinally extending axis X-X to and from a predetermined position relative to a support 16.

The lifter 10 includes a pair of arms 20 having upper portions 17 and lower portions 15. The pair of arms 20 can be longitudinally spaced apart and axially aligned with the longitudinally extending axis X-X of pipe 12 while extending upwardly at predetermined angles with respect to the support 16. Each arm defines two limbs 13 which are laterally spaced apart and opposite each other. The limbs 13 are typically, but not necessarily, identically shaped and configured. As shown, the lower portions 15 of the pair of arms 20 are pivotally connectable to the support 16.

The lifter 10 further includes a pivot 22, which is defined at an end of each lower portion 15 of each arm 20. The pivot 22 permits movable connection of the pair of arms 20 to opposing lateral sides of the support 16.

The lifter 10 also includes a pair of support members 14, each extending perpendicular to the longitudinally extending axis X-X of the pipe 12. The pair of support members 14 is arranged to be fixedly mounted upon central portions 19 of the pair of arms 20 so as to support the pipe 12 disposed transversely with respect to the pair of support members 14.

Moreover, the lifter 10 includes retractable and extensible mechanisms 30 operatively connected to upper portions 17 of each one of the arms 20. In the Figures, each one of the retractable and extensible mechanisms 30 includes a hydraulically actuated piston 36 displaceably located within a cylinder 34 such that said piston 36 is operably permitted to move rectilinearly within said cylinder 34 upon actuation thereof so as to thereby selectively displace the respective upper portions 17 toward and away from each other. It will be appreciated that a pair of elongate rods 90, acting as fail-safe mechanisms, may further form part of the retractable and extensible mechanisms 30. The pair of elongate rods 90 typically extends respectively linearly above the hydraulically actuated piston 36. Each one of the elongate rods 90 has a threaded outer surface to which lock-out nuts 92 are provided such that oppositely disposed ends of the elongate rods 90 can be locked out when the arms 20 reach a predetermined angle corresponding to predeterminedly desired elevation levels of the support members 14.

In use, when the retractable and extensible mechanisms 30, being the hydraulically actuated piston 36 and/or are the elongate rods 90 are retracted, the upper portions 17 of each arm 20 is drawn together so as to cause each arm 20 to pivotally move around the lower portions 15 of the arms 20 relative to the support 16 and thereby elevate the pair of support members 14 so as to, in turn, elevate the structure 12 supported upon the support members 14. On the other hand, when the retractable and extensible mechanisms 30, being the hydraulically actuated piston 36 and/or are the elongate rods 90 are retracted, are extended, the upper portions 17 of each one of the arms 20 are moved apart from each other so as to cause each one of the arms 20 to pivotally move the lower portions 15 of the arms 20 relative to the support 16 and thereby lower the support members 14 so as to, in turn, lower the pipe 12 supported upon the support members 14. It will be appreciated that in so doing, respective limbs 13 of each of the arms 20 flank the pipe 12 and is located within the limited space (not shown) available between laterally disposed pipes 12.

In order to be effective within the restricted space between pipelines 12, each of the limbs 13 are formed from a planar material. The planar material may be sheet material such as a metal alloy having a high strength to mass ratio. It is however envisaged that other materials may also fall within the ambit of the present invention.

As best shown in Figure 3, a positioning bracket 18, having a cross-member 21 flanked by two laterally spaced apart legs 23, is provided for use with the lifter 10. The cross member 21 is shown to be connectable to the support 16 such that a lower end 25 of each of the legs 23 movably accommodates each of the pivots 22 respectively.

Figure 3 depicts how each one of the pivots 22 is provided with a protuberant formation configured to bear against and prop the lower portions 15 of the arms 20 against an outer surface of each of the laterally spaced apart legs 23.

Referring to Figures 1 and 2, an aperture through which each respective support member 16 can operatively extend, is defined in the central portion of each of the arms 20 and extends in line with each other through central regions in the limbs 13. The central regions of the limbs are bent, as shown in the drawings, at an angle of between 100° and 130° so as to thereby permit upward movement of the support members 16 when the retractable and extensible mechanisms 30 are actuated.

The functionality and effectiveness of the lifter 10 is best depicted in Figures 1 and 2 wherein the lifter is shown to be in raised and lowered positions respectively during use thereof in areas where space between structures or piping 12 is limited.

Accordingly, the applicant believes that this invention extends to a method for selectively raising and lowering a structure or pipe, often through which live feed is forced, to and from a predetermined position relative to a support 16. The first step of method 100 includes provision for a support 16 on which the lifter 10 can be mounted.

The second step includes provision for a lifter 10, as described in the aforementioned description, for bestriding the pipe 12 with the pair of arms 20 with its two associated limbs 13 facing each other being axially aligned with the longitudinally extending axis X- X of the pipe 12.

Step 3 includes longitudinally spacing the pair of arms 20 apart from each other with respective limbs 13 flanking lateral sides of the pipe 12. Then the pivots 22 are movably connected to the support 16. The arms 20 are being longitudinally spaced apart and axially aligned with an elongate axis X-X of the pipe 12 while extending upwardly at predetermined angles with respect to the support 16.

Step 4 includes fixedly mounting a pair of longitudinally extending support members 14 upon central portions 19 of the pair of arms 20 so as to support the pipe 12 disposed transversely with respect to the pair of support members 14. Step 5 includes operatively connecting retractable and extensible mechanisms 30 to upper portions 17 of each one of the pair of arms 20 such that as the retractable and extensible mechanisms 30 are retracted, the upper portions 17 of each one of said pair of arms 20 are drawn together so as to cause each one of the pair of arms 20 to pivotally move around the pivots 22 of the arms 20 relative to the support 16 and thereby elevate the pair of support members 14 so as to, in turn, elevate the pipe 12 supported upon the support members 14. Step 6 provides for the retractable and extensible mechanisms 30 to be extended, so that upper portions 17 of each one of the pair of arms 20 are moved apart from each other so as to cause each one of the pair of arms 20 to pivotally move the lower portions 15 of the pair of arms 20 relative to the support 16 and thereby lower the pair of support members 14 so as to, in turn, lower the pipe 12 supported upon the support members 14.

The method as described above is optionally believed to utilize a positioning bracket 18 securable to the support 16 to movably accommodate and seat the pivots 22 to the support 16.

A reasonably skilled artisan in the field of the art is after reading this specification, expected to understand the use and importance of employing the lifter 10, and its associated components, in areas where space between longitudinally extending structures to be lifted are limited. Accordingly, components of the lifter such as, for example, the arms 20, positioning bracket 18, support members 14 is believed to also fall within the ambit of the current invention and therefore protection of same is also sought.

The applicant believes that safe and effective structure lifting and lowering is accomplished in tight spaces when the above described lifter 10 and associated method 100 are employed.

The monopoly for which protection is claimed is set out in the accompanying Claims.