GB2095729A

GB2095729A - Improvements in or relating to a method of and apparatus for anchoring a pipe or cable or the like

Info

Publication number: GB2095729A
Application number: GB8110290A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-04-01
Filing date: 1981-04-01
Publication date: 1982-10-06
Also published as: GB2095729B

Abstract

A method of providing pairs of anchoring contrivances 6 each incorporating at least a rigid shaft in ground adjacent to but on opposing sides of a pipe or cable 33 by means of an anchor driving-mechanism guide frame provided with a movable powered impactor. The anchors may be installed either successively or simultaneously with their longitudinal axies inclined at any angle to the vertical and at variable distances apart. The pipe or cable is secured to the installed anchor shafts by a device comprising a pipe saddle seated over a minor circumferential arc and rotationally attached to a bar or beam whose end lengths are each secured to an associated anchor shaft by an adjustable clamp which is slideable along, and rotatable about both the beam and shaft. Pipe or cable bed support plates may be installed adjacent to or beneath the pipe or cable, being restrained by an associated anchor shaft. <IMAGE>

Description

SPECIFICATION An improved method of and apparatus for anchoring a pipe or cable or the like to a sea or river bed or elsewhere where it is necessary to restrain the pipe or cable against displacement This invention relates to improvements in a method of and apparatus for anchoring and is particularly concerned with the anchoring of a pipe or electrical cable or the like to the beds of seas or rivers, such under-water anchoring being necessary to prevent displacement of the pipe or cable by forces applied transversely to the longitudinal axis of the said pipe or cable.

Many methods of under-water anchoring, at present in use, require anchors to be either drilled into, or screwed into, the material forming the sea or river bed, and reliance on the holding-power of each anchor is thereafter placed on the resistance of the disturbed material at, or proximate to, the inter-faces of the anchor heads or screw surfaces.

The accurate positioning of such anchors, in relation to the pipe or cable they are to restrain, is difficult and expensive and, moreover, is frequently undertaken in conjunction with the seating of the pipe or cable saddles or similar connectors, with consequent risk of damage to the pipe or cable or protective coatings thereto and uncertainty concerning the proper fitting of the saddles and the final stressing of the saddle, pipe or cable or protective coatings thereto.

It is one object of the present invention to provide an improved method of installing anchors in earths or other naturally occurring materials comprising the beds of seas or rivers to depths within the earth or other material masses where there is a sufficient resistance to extraction of the anchors to enable them, when connected to a length of submerged pipe or cable or the like, to restrain or secure the said length against displacement, the method being economic to carry into effect and with a maximum degree of safety against damage to the pipe or cable or protective coatings thereto.

It is a second object of the present invention to provide an improved device for installing anchors in earths or other naturally occurring materials comprising the beds of seas or rivers to depths within the earth or other material masses where there is a sufficient resistance to extraction of the anchors to enable them, when connected to a length of submerged pipe or cable or the like, to restrain or secure the said length against displacement, the device being economic to manufacture and simple to operate and robust in use and with a maximum degree of safety against damage to the pipe or cable or protective coatings thereto.

It is a third object of the present invention to provide an improved method of connecting anchors, installed into the beds of seas or rivers, to a submerged pipe or cable or the like which shall facilitate the correct and accurate positioning and fixing of the connection or saddle to the pipe or cable which shall be economic to carry into effect and with a maximum degree of safety against damage to the pipe or cable or protective coatings thereto.

It is a fourth object of the present invention to provide an improved device or connection or saddle to connect anchors, installed into the beds of seas or rivers or the like to a submerged pipe or cable or the like which shall be economical to manufacture and simple to install and robust in use and which shall bear accurately upon at least a part of the outer surface of the pipe or cable or protective coatings thereof and which shall be installed with a maximum degree of safety against damage to the pipe or cable or the like or to protective coatings thereto.

According to one aspect of the present invention there is provided a method of installing an anchoring contrivance into earth or other naturally occurring material, which comprises the steps of placing the anchoring contrivance whose parts may include a shaft or tube and an associated anchoring mechanism at or near to its leading or penetrating end into an anchor driving mechanism guide frame within which the said anchoring contrivance is free to move in the direction of the longitudinal axis of its shaft, the said longitudinal axis being coincident with, or parallel to, the longitudinal axis of the guide frame and installing the anchoring contrivance into the earth or other material by impact such as is produced, for example, by a pneumatically or hydraulically operated impactor or hammer the impactor or hammer being free to move or to slide within the guide frame in the direction of its longitudinal axis and whose driving or percussive component or components may bear upon the end of the anchor shaft remote from its penetrating end.

With advantage the guide frame together with the moveable impacting, or hammering, mechanism and the anchoring contrivance, is provided with the means whereby its longitudinal axis and that of the anchor shaft may be caused to form any angle in a plane transverse to the longitudinal axis of the pipe or cable with the vertical through the pipe or cable longitudinal axis and to also be positioned relative to the pipe or cable in order that its anchoring contrivance may be installed at any distance from, and in any direction relative to, the pipe or cable depending upon the local configuration of the bed upon which the pipe or cable rests and any prescribed safety zone which may be specified for the protection of the pipe or cable or any coatings or casings thereto.

It will be evident that the method as heretofore described includes for the impacting mechanism being fixed within the guide frame but having its driving or percussive component or components extensible in order to enable the mechanism to continue to transmit impaction to the anchor shaft during its penetration into the earth or other material mass.

According to another aspect of the present invention there is provided a device for installing an anchoring contrivance into earths or other naturally occurring material which comprises a driving mechanism guide frame within which the anchoring contrivance, whose parts may include a shaft or tube and an associated anchoring mechanism at or near to its leading or penetrating end, is free to move in the direction of the longitudinal axis of its shaft, the said longitudinal axis being coincident with, or parallel to, the longitudinal axis of the guide frame, the installation of the anchoring contrivance being effected by means of impacting or hammering or impacting and rotational forces applied to the anchor shaft produced, for example, by a pneumatically or hydraulically actuated impactor or hammer which is free to move or to slide within the guide frame in the direction of its longitudinal axis and whose driving or percussion component or components may bear upon the end of the anchor shaft which is remote from its penetrating end.

With advantage the guide frame is provided with the means whereby its longitudinal axis may be caused to form any angle, in a plane transverse to the longitudinal axis of the pipe or cable to be anchored, with the vertical through the pipe or cable longitudinal axis and to also be positioned relative to the pipe or cable in order that its anchoring contrivance may be installed at any distance from, and in any direction relative to, the pipe or cable.

The anchor driving mechanism guide frame may be suspended from a crane or similar lifting apparatus and for ease and safety in manoeuvring under-water may be provided with one or more buoyancy tanks whose lifting effect may be pneumatically varied.

It will be apparent that while the invention is primararily concerned with the under-water anchoring of pipes or cables and the like the method and apparatus heretofore described could, with advantage, be applied to the anchoring of objects on dry land such as, for example, a telegraph pole or a mast, the guide frame together with its driving impactor and associated pneumatic or hydraulic actuating equipment being appropriately mounted on a vehicle to afford mobility over all types of terrain.

It will also be apparent that the characteristics of the earths or other materials comprising an area in which anchors are to be located, such as, for example, cohesive properties, or coral strengths, or conglomeration, will determine the type or types of anchor to be installed by the device heretofore described.

According to a preferred embodiment of the invention there is provided a device for installing a plurality of anchoring contrivances either simultaneously or successively in earths or other naturally occurring materials, proximate to a pipe or cable or the like, comprising two anchor driving mechanism guide frames as heretofore described connected together by adjustable bars or similar linkages so that their longitudinal axes may form any angles on opposing sides of the vertical through the longitudinal axis of the pipe or cable.

The compound anchor driving mechanism guide frames may be suspended from a crane or similar lifting apparatus and for ease and safety of manoeuvring under-water may be provided with one or more buoyancy tanks whose lifting effect may be pneumatically varied. Preferably each of the compound guide frames is also provided with feet or skids or similar means whereby the frames can be supported in their installing attitudes on the sea or river bed adjacent to the pipe or cable which is to be secured by their anchors.

After anchors have been installed into a sea or river bed as heretofore described it will be necessary to connect them to the adjacent pipe or cable they are to restrain in a manner which will cause no damage to the said pipe or cable or to any protective coatings or casings thereto.

According to one aspect of the present invention there is provided a method of providing a pipe and anchor connection comprising a saddle or pipe seat which may be accurately engaged over an upper minor arc of the pipe or casing circumference and which is connected, by a boss or bolt or the like whose longitudinal axis bisects the saddle arc and which passes through the centre of the pipe, to a bar or plate which is tangential to the saddle and is free to rotate about the boss or bolt the ends of the bar or plate being provided with means for securely connecting them or their associated anchor shafts such as ring bolts or swivel clamps or the like.

According to another aspect of the invention there is provided a pipe and anchor connecting device comprising a pipe saddle which may be seated over an upper arc of the pipe or casing circumference and which is connected to a bar or plate, tangential to the crown of the saddle arc by a boss or bolt or similar connection about which the said bar or plate is free to rotate. The ends of the bar or plate are provided with means for securely connecting them to their associated anchor shafts such as, for example, ring bolts or swivel clamps or the like.

It will be apparent that the combined rotational and locating actions of the pipe saddle crown boss or bolt and the bar or plate end swivel couplings will enable the saddle to be accurately seated on the pipe or cable whether or not the adjacent associated anchors have been precisely placed or have been deflected by local and random obstructions encountered during their installation into the earth or other material masses.

It will also be apparent that with one end of the bar or plate secured by one end swivel coupling to its adjacent associated anchor shaft the saddle may be caused to bear upon the pipe or cable with a specified and carefully imposed force applied to the other end of the bar or plate prior to it being also secured to its adjacent associated anchor shaft.

With advantage the said force applied by the saddle may be transmitted by the pipe or cable and the surface layers of the ground mass upon which the pipe or cable rests to pressure or thrust plates retained by the anchor shafts, the said pressure plates also preventing surface scouring of the bed in the vicinity of the restraining anchor assembly.

Also with advantage the pneumatically or hydraulically or similarly actuated impactor or hammer, when operating under-water, may be provided with plates or vanes or surfaces normal to the longitudinal axis of impaction which will impart the reaction of the impactor, or a part thereof, to the water above the said plates or vanes, thereby diminishing the recoil of the impactor and improving its driving effect upon its associated anchor.

Embodiments of the invention will now be described by way of example, reference being made to the accompanying drawings in which:~ Fig. 1 is an elevational view of an anchor driving mechanism frame according to the present invention in which is located an anchoring contrivance and an impactor or mechanical hammer the said frame being provided with means for its suspension and angular adjustment relative to the ground plane or vertical axis.

Fig. 2 is an elevational view of the anchor driving mechanism frame taken at right-angles to the view shown at Fig. 1.

Fig. 3 is an elevational view of the anchor driving mechanism frame in a suspended and angled attitude relative to the horizontal.

Fig. 4 is a part elevational and part sectional view of the lower or leading end of the anchor driving mechanism frame, showing the leading end of the anchoring contrivance and one means of locating it within the frame ready for installation into the ground.

Fig. 5 is a part plan and part sectional view of Fig. 4.

Fig. 6 is an elevational view of two anchor driving mechanism frames connected together so as to form an adjustable compound anchoring device as heretofore described by means of which two anchors may be simultaneously installed the device being provided with skids and buoyancy tanks, part of which at least may also form an exhaust chamber for pneumatically operated impactors.

Fig. 7 is an elevational view of the compound anchoring device taken at right angles to the view shown at Fig. 6.

Fig. 8 is a part-sectional view of a pipe, adjacent to which two anchoring contrivances have been installed whose shafts are connected to the pipe by alternative forms of saddles.

Fig. 9 is a plan view of the form of saddle shown in section on the L.H.S. of Fig. 8.

Fig. 10 is a plan view of the form of saddle shown in section on the R.H.S. of Fig. 8.

Fig. 11 is a part-sectional, part-elevational view of a preferred alternative form of pipe or cable saddle connected to two installed anchor shafts by a connecting or bridging beam whose ends are secured to the shafts by swivel scaffolding couplings or the like.

Fig. 12 is a plan of Fig. 1 1 showing the saddle and connecting, or bridging, beam secured to two anchor shafts whose longitudinal axes have mutually adopted a random three-dimensional angle during their installation into the ground.

Fig. 13 illustrates one form of impactor, or mechanical hammer, connected to the shaft of an anchoring contrivance in an anchor driving mechanism frame and provided with plates or vanes to diminish the recoil of the mechanism when installing the anchoring contrivance under water.

The anchor driving device illustrated in Fig. 1 comprises an anchor driving mechanism frame 1 having a plurality of parallel longitudinal shaped steel or similar members 2 connected at their ends by transverse frame member or fish plates 3 the cross-sectional shape of the frame being such that a driving mechanism 4, as for exmple, a pneumatically or hydraulically actuated impactor or hammer is free to move longitudinally within the said frame 1. The leading or impacting end 5 of the anchor driving mechanism 4 engages with the following end of the shaft of an anchoring contrivance 6 by way of a driving collar 7 and spigot 8 or similar means whereby the longitudinal axes of the impactor 4 and the anchor 6 are maintained in the same alignment as that of the longitudinal axis of the guide frame 1.The anchoring contrivance 6 is also free to move longitudinally within the guide frame 1 the leading end of the anchor shaft being slideable within guideways 9 located at the leading end of the guide frame 1 to maintain the coincidence or parallelism of the anchor shaft and guide frame longitudinal axes.

Although the anchor driving mechanism frame 1 illustrated in Figs. 1 and 2 has parallel longitudinal members 2 each having equal rightangled cross-sections it will be evident that longitudinal members having other cross-sections could be used, such as for example channel or U sections, the requirement being that the anchor driving mechanism 4 shall be free to move longitudinally within the frame as the said mechanism drives the anchoring contrivance 6 out of the frame 1 and into the ground.

Prior to the installation of the anchoring contrivance 6 into the ground it is retained within the frame 1 by a removeable plate 10 or similar retractable mechanism located at, or near to, the lower or leading end of the anchor driving mechanism frame 1.

To the lower or leading end of the frame 1 is also secured a bar or plate 11, transverse to the longitudinal axis of the frame and provided at its end, remote from the frame, with means for attaching a flexible tendon or hinged tie rod 12, whose length may be adjusted.

The upper or following end of the anchor mechanism driving frame 1 is connected by a pinjoint, or similar hinge 13, to one end of a bar or link 14 having at its other end a hook attachment 15 by which both the bar 14 and the driving frame 1 may be suspended. The link 14 is provided with a cleat 1 6 or similar attachment to which the upper end of the flexible tendon or hinged and adjustable tie rod 12 is secured.

Where, in the course of installing the anchoring contrivance 6 into the ground, the driving mechanism 4 advances within the guide frame 1 under its own weight, with advantage, the pin, or hinge 13, may be provided with a pulley wheel or tackle block over which a rope may pass to return the driving mechanism to the upper or following end of the frame after the installation of the anchor has been completed.

The bar or link 14 may also be provided with one or more buoyancy tanks 17 when the anchor driving device is to be operated under-water.

Fig. 3 illustrates the suspended anchor driving device as heretofore described, positioned by the flexible cable 12 to install its anchoring contrivance 6 at an angle 0 to the ground surface, the reference numbers of the several parts of the device being the same as in Figs. 1 and 2.

Fig. 4 is a part-plan and part-sectional view, drawn to a larger scale, of the leading end of the anchor driving mechanism frame 1 shown in Figs.

1,2 and 3, and in particular illustrates one method of providing a removeable guideway 9, within which the anchor shaft is free to move longitudinally within the frame, the said guideway being formed by a plurality of timber or similar spacing pieces located within the guide frame by pins or dowels 18 or the like, which may be withdrawn to allow easy dismantling of the guideway and removal of the driving frame 1 from the following end of the anchor shaft after the anchoring contrivance 6 has been installed into the ground. Fig. 4 also illustrates one method of retaining the anchoring contrivance 6 within the driving frame 1 prior to the installation of the anchor into the ground by means of the removeable plate 10 which is free to slide within slots in the fish-plates 3 and against which the leading end of the anchoring contrivance rests.

Fig. 5 is a part elevational and part sectional view of the leading end of the anchor driving mechanism frame shown in Fig. 4.

Fig. 6 is an elevational view of a preferred embodiment of the invention in which two anchor driving mechanism frames 1 each of which is constructed as heretofore described and each containing a driving mechanism and anchoring contrivance and associated parts, referenced as in Figs. 1 and 2, are connected together by tie beams or struts 19 and 20 and a brace, or braces, 21 each of which has a structural section and strength sufficient to form, with the two anchor driving mechanism frames 1 a rigid combined anchor-driving device. The beams 19 and 20 and the brace or braces 21 are connected to the anchor mechanism driving frames 1 by pin or similarly hinged joints 22 provision being made, for example, by series of holes in the members for the said members 19, 20 and 21 to be connected together at variable points along their lengths.

Each anchor driving mechanism frame 1 is provided with a foot or pedestal 23 whose position, relative to the frame may be varied. In the example illustrated by Fig. 6 the foot 23 is in the form of a tube or skid whose ends are sealed and which is connected to the frame 1 by the arm 24 which is pin-jointed or otherwise hinged to the frame at 25 and is also provided with an arm 26 whose length may be varied and which is hinged to the foot or skid 23 by 27 and to the anchor driving mechanism frame 1 by the hinge at 28. It will be seen that the components 1, 19, 20, 21, 23, 24 and 26 may be so assembled as to permit the compound anchor-driving device to install its anchoring contrivances into the ground in various predetermined attitudes.

The anchor driving device is provided with a lifting eye 29, or similar means for its suspension, and when the device is to be used to drive anchors below water, one or more buoyancy tanks 18 may be secured to the beam 20 to regulate the movements of the device over the sea or river bed.

Where the anchor driving mechanisms or hammers are operated pneumatically, with advantage, the buoyancy tanks 18 may include an exhaust chamber 30 to which the separate exhaust ports 31 of the mechanisms may be connected, the combined exhausts being thereafter returned to above water level by a single vacuum tube 32 connected to the exhaust chamber.

Fig. 7 is a second elevational view of the preferred compound anchor driving device as heretofore described, taken at right-angles to Fig. 6.

Fig. 8 includes sectional elevational views of two alternative methods and apparatus by means of which the following ends of two anchor shafts 6 each installed into the ground at an angle 0 to the surface level and proximate to a pipe or cable 33, or the like, may be secured to the said pipe or cable; Figs. 9 and 10 being plan views of the alternative elevational views of Fig. 8.

Fig. 11 is a part-elevational and part-sectional view of a preferred method of and apparatus by means of which the upper or following ends of two anchor shafts 6, driven into the ground at angles b to the surface level and proximate to a pipe or cable 33 or the like, may be attached to the said pipe or cable in a manner which will ensure a maximum degree of structural safety to the pipe or cable and any coatings or casings thereto. The attachment between the anchor shafts 6 and the pipe or cable 33 is by a bar, or tube, or beam 34, connected to the said shafts 6 by swivel clamps or couplings 35 such as, for example, by swivel scaffolding clamps, which will allow the tube or beam 34 to adopt an unstressed attitude relative to the two shafts 6 for all small random displacements of the shafts during their installation into the ground mass. The tube or beam 34 is provided with a housing, or hole, at its mid-span into which is freely seated a spigot 36 formed on a saddle 37 which will accurately sit upon the pipe or cable or any coatings or casings thereto.The housing, or hole, in the beam 34 being larger in diameter than the diameter of the spigon 36 it will be seen that for any unstressed position of the tube or beam 34, relative to the axes of the pipe or cable 33 and the anchor shafts 6, the saddle 37 can be accurately seated over its contact arc surface on the pipe or cable and that a predetermined pressure may be applied to the saddle by the tube or beam 34 prior to its being secured to the two anchor shafts 6 by the swivel clamps 35, the aforesaid predetermined pressure being applied, for example, to one or both ends of the tube or beam 34 by the lever tool illustrated at 38.As described heretofore the pressure applied to the pipe or cable 33 by the saddle 37 will be communicated to the earth bed 39 upon which the pipe or cable rests and also, with advantage, to pressure or thrust plates 40 retained by the anchor shafts 6, the pressure plates 40 also preventing surface scouring of the bed in the vicinity of the restraining anchor assembly.

Fig.12 is a plan view of the preferred method and apparatus as heretofore described and ilustrated in Fig. 11.

Fig. 13 illustrates a pneumatically or hydraulically actuated impactor or hammer 4 which, when used in an anchor driving device, as heretofore described, for the driving of anchoring contrivances underwater, is provided with one or more plates or vanes 41 which will transmit at least a part of the reaction of the impactor 4 to the water above the plate, or plates, 4 thereby diminishing the recoil of the impactor and improving its driving effect upon its associated anchoring contrivance.

Claims

1.A method of anchoring a pipe or electrical cable or the like which comprises the steps of installing a pair of anchoring contrivances, each of whose parts include at least a rigid anchor shaft, into earth or ground adjacent to but on opposing sides of the pipe or cable by means of a device comprising an anchor driving-mechanism guide frame in which the anchor shaft, after insertion, is free to move in the earth-penetrating direction of its longitudinal axis, such axis being coincident with, or parallel to, the longitudinal axis of the anchor driving-mechanism guide frame, the said anchor shaft being installed into earth or ground by percussive or impacting and rotational forces applied to it by a power-operated hammering mechanism engageable with the anchor shaft and slideable within the anchor driving-mechanism guide frame in the penetrative direction of the anchor shaft, or whose anchor-driving component or head is advanceable in the penetrative direction of the anchor shaft and engageable therewith, and thereafter connecting the said pipe or cable or the like to the shafts of the installed anchoring contrivances by a device comprising a pipe or cable saddle seated over a minor circumferential arc and connected at its crown by a boss or bolt or the like to a bar or beam so as to be rotatable therewith each of the end lengths of the said bar or beam being connected to an associated anchor shaft by a coupling or clamp which is slideable along and rotatable about the said end length of the bar or beam and the associated anchor shaft.

2. A method according to Claim 1, in which the anchor driving-mechanism guide frame is provided with means whereby its longitudinal axis can be inclined at any angle to the vertical through the pipe or cable and be located at any distance from the centre thereof.

3. A method according to Claims 1, and 2, for anchoring a pipe or cable or the like whereby a pair of anchoring contrivances each of whose parts include at least a rigid anchor shaft are installed at the same time into earth or ground adjacent to but on opposing sides of a pipe or cable by means of a device comprising two anchor driving-mechanism guide frames connected together by adjustable bars or rods so that their longitudinal axes can be inclined at any angles to the vertical through the pipe or cable and be located at any opposing distances from the centre thereof, the shafts of the said anchoring contrivances being simultaneously installed by percussive or impacting and rotational forces applied to them by power-operated hammering mechanisms operable in both anchor drivingmechanism guide frames.

4. A device for installing an anchoring contrivance whose parts include at least a rigid anchor shaft into earth or ground comprising an anchor driving-mechanism guide frame in which the anchor shaft, after insertion, is free to move in the earth-penetrating direction of its longitudinal axis, such axis being coincident with, or parallel to.

the longitudinal axis of the anchor drivingmechanism guide frame in which is provided a power-operated hammering mechanism engageable with the anchor shaft and effective in driving the anchoring contrivance into earth or ground by percussive or impacting and rotational forces.

5. A device according to Claim 4, in which the anchor driving-mechanism guide frame is provided with means whereby its longitudinal axis can be inclined at any angle to the vertical through the pipe or cable and be located at any distance from the centre thereof.

6. A device according to Claims 4, and 5, comprising two anchor driving-mechanism guide frames connected together by adjustable bars or rods so that their longitudinal axes can be inclined at any angles to the vertical through the pipe or cable and be located at any opposing distances from the centre thereof.

7. A device for connecting together a pipe or cable or the like to the shafts of a pair of anchoring contrivances installed in earth or ground adjacent to but on opposing sides of the said pipe or cable comprising a pipe or cable saddle seated over a minor circumferential arc and connected at its crown by a boss or bolt or the like to a bar or beam so as to be rotatable therewith each of the end lengths of the said bar or beam being connected to an associated anchor shaft by a coupling or clamp which is slideable along and rotatable about the said end length of the bar or beam and the associated anchor shaft,

8. An opposing pair of pipe or cable bed support plates or surfaces positioned in the upper layers of earth or ground adjacent or beneath a pipe or cable anchored in accordance with Claims 1, 3, 4, 6 or 7 each said plate or surface bearing against and being positionally restrained by a shaft of an installed anchoring contrivance.

9. A device comprising one or more vanes or surfaces secured to a movable anchor-driving mechanism to be operable under-water in a guide frame in accordance with Claims 1,3, and 4, the said vanes or surfaces being formed to a shallow wedge-shaped configuration whose tapered edge is normal to, and in the direction of the impacting direction.

10. An anchorage constructed, arranged and adapted to operate substantially as herein described with reference to the accompanying drawings.