[0001] The invention relates to a resin pump and to a system for pumping a resin into a hollow rock anchor.

[0002] It is known to introduce into a hollow rock anchor a two par adhesive system which, when the two parts contact and mix _f harden to set the rock bolt within a rock hole that it is Inserted within.

[0003] An example of such a resin system is described in WO2012/013868. To introduce the resin system into a holiow rock anchor, an injection system such as that described in WO2010/031132 can be used.

[0004] A problem with the systems described in the publications aforementioned is that each part of the two part resin system originates from its own source. Each part then needs to be separately, yet synchronously, pumped from the respective source along respective fluid conduits to meet at an injection system that would then introduce the two parts to the anchor.

[0005] To do this, each source requires a pump and the rate of pumping from each source requires co-ordination to ensure the correct mix ratio of each part of the resin system. fOOOS] The injection system would need to keep the parts separate in respective passageways as each part flows there-through to prevent the parts mixing and hardening within the injection system. However, once the parts leave the system and flow into an interior of the rock anchor, they coma into mixing contact. With mixing of the parts comes the propensity to react and harden. If the hardening of the resin parts occurs in a space within the rock anchor in advance of a noz e of the injector system, there is the risk that the injector system will adhere to the rock anchor.

[0007] The invention at least partially addresses the aforementioned problems,

SUMMARY OF INVENTION

[SOQB] Hereinafter the terms rock anchor and rock bolt are used interchangeabiy to describe a device which has an elongate foody and which is inserted into a hole drilled into a rock face to stabilize the rock to prevent collapse or rock fall.

[00 9J Hereinafter, "adhesive", or "resin" refers to a system which includes at least one low viscosity liquid adhesive component which is free-flowing before activation and which after activation, sets of hardens, An "adhesive component" bears corresponding meaning. The terms "adhesive" and "resin" are used interchangeably.

[0010] The invention provides an adhesive pump which includes: a tubuiar housing which has an inlet and an outlet; a cartridge in the tubular housing with a leading end and an opposed trailing end, the leading end having an opening in fluid communication with the outlet; a first compartment and a second compartment defined within the cartridge, for respectively containing a first component and a second component of an adhesive system; a pressing member positioned within the cartridge towards the trailing end; and wherein the pressing member is caused to move, in response to fluid flowing Into the tubular housing from the inlet, towards the leading end to force the first and second adhesive components from respective first and second compartments towards the outlet.

[0011] Preferably the inlet and the outlet are defined through a first end and an opposed second end respectively.

10012] The pressing member may be slidingly and sealingly engaged with inner walls of the cartridge,

[0013] The cartridge may be made of a rigid plastics material.

[0014] The cartridge may be complementary dimensioned to snugly fit within the housing. Preferably, the cartridge is sealingiy fitted within the housing,

[0 1S] The inlet may be outwardly adapted to engage with a conduit end of a hydraulic fluid delivery system.

FJ301S] The Inlet may include a valve,

[0017] The outlet may be outwardly adapted to engage with a rock anchor resin input conduit,

[0018] The cartridge may include an elongate tube which fits within the housing in co~axial extension and which defines the first compartment and whereby the second compartment is defined by a space between the cartridge and the tube. [0019] In one embodiment, a wail of the tube may be adapted to axiaily compress in a controlled manner about predefined annular zones, when a force Is applied at one end, to extrude its adhesive content,

[0020] Preferably, the tube is made of a suitable flexible plastics material.

[0021] The tube may be a tubular beilows-type tube, its wall comprising of a plurality of corrugated annular sections, each one of these sections defining an annular zone about which the tube is adapted to asdally compress.

|0 22] In another embodiment the pressing member may include a bladed formation,

[0023] In this embodiment the tube may be made of a rigid plastics material.

[0024] ^ this embodiment, the bladed formation facilitates advance of the pressing member towards the leading end of the cartridge, in response to fluid flowing info the tubular housing from the inlet, to thereby force the first and second adhesive components from respective first and second compartments towards the outlet, by severing a wall of the tube, such that the components are kept fluidly separated until exit from the outlet

[002β] The invention extends to a system for introducing a two-part adhesive to a hollow rock anchor which system Includes; an adhesive pump as described above; a connector tube which is engageable, at opposed first and second ends, to the outlet of the pump and the rock anchor respectively to provide a fluid conduit from the pump housing to an interior of the rock anchor; and a static mixer engaged with the tube, interposed in the fluid conduit,

[0028] From another perspective, the invention provides a system for introducing a two-part adhesive to a hollow rock anchor which system includes: a pump which includes a tubular body, which is internally adapted !o contai _: and to keep in fluid separation, a first and second part of the adhesive and which has an input end and an output end and which input and is adapted to engage with a source of a hydraulic fluid, and a drive means within the tubular body which is caused to advance towards the output end in response to the fluid flowing into the input end to thereby drive the first and the second adhesive parts separately towards the output end; a connector tube which is engageable, at opposed first and second ends, to the output end of the pump body and the rock anchor respectively to provide a fluid conduit to the adhesive from the pump body to an interior of the rock anchor; and a static mixer engaged with the tube. Interposed in the fluid conduit to receive the first and the second parts of the adhesive and to cause the parts to mix before delivery to the rock anchor,

|0027] The drive means may be a piston, a plunger, a pressing member or the like.

[002S] Preferabiy, the static mixer is engaged with the tube at or towards its first end,

[0029] The output end of the tubular body may be adapted to releasabiy engage the first end of the connector tube.

[0030] The tube may be a flexible tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The inv ntion is further described by way of example with reference to the accompanying drawing in which:

Figure 1 diagrammaticaily Illustrates a system for introducing a two-part adhesive to a hollow rock anchor in accordance with the invention;

Figure 2 diagrarnmaiicaliy illustrates a resin pump of the system of Figure 1 ;

Figure 3 is a cross section through line 3 - 3 of Figure 2;

Figure 4 is a partially sectioned perspective view of a pressing member of the resin pump,

DESCRIPTION^ PREFERRED EMBODIMENT

[ 032J With reference to the accompanying Figures, the invention provides a pumping system 10 for introducing a two-part adhesive through a tubular rock anchor 12, info a rock hole 14 in which the rock anchor is placed.

[0033] The system 10 includes a resin pump 18 and a connector tube 18, The connector tube 18, made of a suitable plastics material, is flexible to accommodate a variety of positions at which the pump 16 engages with the tube,

[0034] The tube 18 has opposed first and second ends (20, 22), with the first end adapted to releasab!y engage the resin pump 18 and the second end engaged to a trailing end 24 of the rook anchor 12.

[0035] The tube includes a static mixer 26 at the first end 20 of the tube 18,

[003S] The resin pump 16 has a tubular housing 28 defining an internal volume 30 in which a resin cartridge 32 is located. The resin cartridge is complementary dimensioned to fit snugly within the volume, sealed against interna! wails 34 of the housing 28.

[003?] The housing extends between an inlet 38 and an outlet 40 and is defined through the inlet end 36 and the outlet end 38A respectively with an inlet valve assembly and outlet nozzle (42, 44) respectively exteriorly projecting from the inlet and outlet The inlet valve assembly includes a valve 48.

[0038] The inlet valve assembly is oonnecfabte to a conduit {shown as an arrow in Figure 1) leading from a hydraulic fluid source 48.

[0039] The outlet nozzte 44 is adapted to reieasibly engage with the first end 20 of the connector tube 18. A dotted line with opposed directional arrows in Figure 1 serves to illustrate this releasable interconnectadness of the resin pump 16 with the connector tube 18. f0040] It is anticipated, in a preferred embodiment, that the connector tube 18 is permanent or fixed feature of the rock anchor 12 and that the resin pump 18 is attached to th connector tube, actuated to extrude the two-part adhesive, which flows through the tube 18 into the rock anchor, along an internal bore 50, through an opening in a leading end 52 of the anchor, to flow into an annular space 54 between the anchor and the rock hole walls,

[0041] It is anticipated that the resin cartridge 32 of the resin pump 18 can come in many embodiments. What is common in all embodiments, is that the cartridge includes two compartments, respectively designated 60A and 60B, each of which contains a part or component of the two-part adhesive and a pressing member 62. [0042] An embodiment 32A of the cartridge is illustrated diagrammatically in Figure 1 and in more detail in Figure 2,

[00431 cartridge 32A includes a first tube 84 which is positioned co-axially within a second tube 66. The annular space between the first and the second tubes (84, 86} defines the first compartment 80A and a second compartment 8GB is defined within the first tube 84. The compartments are divided by a partitioning wail being the wall constituting the first tube. Each compartment contains a discrete fluid part of a two part adhesive system,

[0044] A pressing member 82A is provided, initially located (i.e. before use of the resin pump), towards an end 88 of the cartridge 32A. The pressing member, as best illustrated in Figure 4. has a unitary body 70 comprising of a first cylindrical central part 72 and a second annular outer part 74, The first part and the second part are unitariiy inter-linked by a blade formation comprising of three radially arranged blades, respectively designated 76A, 76B and 78C (see Figure 3). [004S] The pressing member has a core 78 made of a suitable resilient plastics material, coated with an outer seaiing layer 80 of a rubber-like material which is sufficiently strong yet flexible enough to provide adequate sealing. This sealing layer is moulded to provide a number of annular seaiing ridges 82 (see Figure 4), The blades are not coated with the sealing layer and each presents a cutting edge to the partitioning wall,

[0048] The first part and second parts {72, 74) of the pressing member 82A are complementariiy shaped and dimensioned to sealingly locate within the tube (compartment) 8GB and the annular space (compartment) 80A respectively to respectively seal off the compartments, from a trailing position as the pressing member 82A advances.

[Θ047] With fluid input into the volume 30, behind the pressing member 32A, through the nlet 38 by attaching the valve assembly 42 to the hydraulic fluid source 48, the pressing member s actuated to advance within the cartridge 32A. As the pressing member advances, the blades 76 cut into the partitioning wall of the tube 84 to enable further advance, whilst sealing engagement is maintained by the respective parts (74, 72} against the respective walls surfaces, to force the respective adhesive parts out of the respective compartment (80A, 80B) towards a leading end 78 of the cartridge 32A, without backfiow,

[0048] The leading end 78 of the cartridge 32A is tapered towards the outlet nozzle 44, with each compartment 60 tapering accordingly, maintaining discrete passageways for the respective adhesive part, thus maintaining fluid separation until the adhesive parts exit the resin pump 18 at the nozzle 44, into the connection tube 18 and the proximally positioned static mixer 28.