Abstract: An encapsulation system for use in securing a rock bolt in a bore hole drilled into a rock face to be stabilised, the encapsulation system comprising at least two separate encapsulation mediums and one or more elongate cartridges containing the encapsulation mediums, each the cartridge having a frangible casing, the encapsulation mediums including: a first encapsulation medium comprising a curable first resin formulation; and a second encapsulation medium; wherein, following use in securing a rock bolt, the second encapsulation medium has a lower bond strength and/or a lower compressive strength than the first resin formulation.

Abstract: Provided are a grouting anchor bolt and a grouting anchor cable for supporting of large deformation and constant resistance and a quantitative roadway supporting method, wherein an anchor bolt comprises a casing, a hollow rod body, an anchor cylinder, a tray, a fastening nut and a clamping pin, a front end of the casing is sealed and a rear end of the casing is opened, a middle position of the casing is provided with a plurality of grouting holes, an inner diameter of the casing from the middle position of the casing to the rear end becomes small gradually, a side surface of a front end of the hollow rod body is sleeved with an anchor cylinder, the anchor cylinder is inserted into the casing and movably connected with the casing, the anchor cylinder is connected with the casing through the clamping pin, a rear end of the hollow rod body is sequentially assembled and connected with the tray and the fastening nut.

Abstract: A sock anchor unit (10) comprises an inner longitudinal hollow spine (12), an outer fabric sleeve (14) arranged to envelop the outside surface of the inner hollow spine (12) such that a gap is defined between the outside surface of the inner hollow spine (12) and an inner surface of the outer fabric sleeve (14) and a plurality of elongated reinforcing members (22), wherein each elongated reinforcing member (22) extends longitudinally within the gap. The inner hollow spine (12) comprises at least one substantially laterally extending opening from inside to outside of the inner hollow spine (12). The opening allows cementitious fluid which is pumped into the anchor unit to fill the gap between the hollow spine (12) and outer fabric sleeve. A fastening member (28, 32) is provided on each end of the sock anchor unit (10).

Abstract: Rock anchors, inflation chucks, and inflation systems such as those described herein, allow for substantially complete draining of fluids from interior volumes of the rock anchors. In various situations, corrosive fluids may be introduced to the rock anchor, including inflating the rock anchors and during normal use, such as by groundwater intrusion. The inflation chucks described herein include multiple inflation paths for more effectively introducing and draining fluid from rock anchors during inflation processes and during general use.

Abstract: The present invention provides a self-drilling and self-anchoring extendable anchor rod applicable to soft and weak coal rocks and an anchoring method thereof, which are suitable for supporting soft and weak coal rock mass in roadways.

Abstract: A fastener for fastening adjacent portions of a structure requiring fastening is described. The present fastener enables delivery of grout or a sealing composition into a passage between or adjacent the portions of the structure or between adjacent parts of the structure. The portions of the structure may include tubbing rings and segments thereof. The fastener includes an inlet and at least one outlet. The inlet and at least one outlet are connected by a channel. Grout or sealing composition can be delivered into the inlet where it flows through the channel, outwardly through the at least one outlet and into the passage requiring sealing. A method of sealing a passage in a formation using the fastener is also described.

Abstract: This invention discloses an underground rock anchoring system comprising a rock bolt having a bolt shaft operatively locatable in an elongate rectilinear hole drilled into a hanging wall such that an end portion of the bolt shaft protrudes from the hole, the bolt shaft having a side wall defining a hollow internal chamber extending along at least part of the length of the bolt shaft, a bearing plate adapted to be fitted over the protruding end portion of the bolt shaft for bearing against a rock surface of the hanging wall; and fastening means for pulling the bearing plate taut against the rock surface of the hanging wall. The invention also extends to a rock anchoring method in which such system is used.

Abstract: Anchoring system is appropriate for solid rock and concrete (2) and any firm bearing system. The anchor rod (4) of for example a threaded bar out of a shape memory alloy (SMA) is held in the armature bore (3) with a filling compound (5) as anchoring means. For filling the achoring bore (3) between anchor rod (4) and wall of the armature bore (3) a heat resistant filling compound (5) of a polymer connection on a two-component-basis or such on a cementous basis is used. Then the anchor rod (4) is heated by heat input over its butt that is emerging the filling compound on its austenit phase, which pre tensions the anchor rod (4). Finally, after the cooling of the filling compound (5) the anchor rod (4) is cooling of to ambient temperature. A counter bearing board (10) lays on the outer wall (1) around the port of the armature bore (3) and is tensed up with the anchor rod (4).

Abstract: An accelerator mixture for peroxide hardeners, in particular an accelerator mixture for an organic peroxide-curing resin mixture, a two-component mortar system containing the same for chemical fastening and use of the same for chemical fastening of anchoring elements in boreholes are disclosed. Using a mixture of bis-N-substituted p-toluidines with bis-N-substituted anilines or bis-N-substituted m-toluidines, it is possible to provide a mortar composition for chemical fastening of anchoring elements in boreholes, which will have an improved low-temperature curing and improved load ratings at high temperatures with an extended gel time.

Abstract: The present invention includes a rock bolt having a longitudinally expandable tube. The tube includes a longitudinally extending depression that defines a temporary enclosed longitudinal passageway. The rock bolt further includes a shielded distal end to prevent debris from entering the temporary enclosed longitudinal passageway. The distal end is shielded using a cover which may be a plug or a cap and may provide a rounded tip for the rock bolt. The plug may be spherical. The cap may be attached such that its proximal end abuts the distal end of the rock bolt, is inserted into the distal end of the rock bolt, or extends beyond the distal end and along the sidewall of the rock bolt. The present invention also includes a method of making such a rock bolt and a method of using such a rock bolt.

Abstract: A rock anchor includes an elongate tubular body which extends between a first end and an opposing second end and a cartridge contains a multi-component adhesive system in the tubular body. The cartridge has a rigid tubular housing within which at least one compartment is defined, and in which is contained an adhesive component of the system. The at least one compartment yields to volumetrically reduce under fluid pressure created by a fluid input into the housing, to thereby extrude the adhesive components.

Abstract: An adhesive package and use thereof with an anchoring element is disclosed. The adhesive package includes a tubular foil pouch for receiving a multi-component adhesive mass having at least one hardener component and one reactive resin component that is separate from the hardener component. The reactive resin component has at least one first compound and one second compound which harden at different rates and which are arranged in succession in the tubular foil pouch. The reactive resin component has an additional polymerizable compound which is arranged behind the second compound on an end of the foil pouch that is opposite from the first compound. The additional polymerizable compound hardens more slowly than the second compound and provides a leak protection for the second compound and/or the hardener component.

Abstract: A bolt includes a tube, at least a portion of which is hollow, having a top and the bottom and at least one dimple. The bolt includes an insert fixed to the interior of the tube in proximity to the dimple with the dimple disposed between the insert and bottom of the tube. A method for a bolt includes the steps of inserting a resin cartridge into a hole.

Abstract: A mine roof bolt includes an elongated rod and a polymer coating layer. The elongated rod has a first end and a second end with a protruding portion extending radially outward from the elongated rod. The polymer coating layer covers at least a portion of the elongated rod between the first and second ends. The elongated rod is movable relative to the polymer coating layer in an axial direction. The elongated rod has a first position where the elongated rod has a predetermined axial position relative to the polymer coating layer and a second position where the elongated rod has a displaced axial position relative to the first position.

Abstract: The present invention is directed to sealable rock bolts that prevent water leakage through the bolt, a kit containing portions of such bolts prior to assembly, installation, and use, and a method of using such sealable rock bolts. Such rock bolts are fastened in place in a roof, wall, or bottom of an underground region via pressure fitting or the like. The rock bolt contains a sealing unit that contains a liquid water activated, expandable hydrophobic pre-polymeric resin. The sealing unit has side, top, and bottom portions that are degradable by water to permit the resin to expand upon contact with water and to seal the bolt to prevent water passage through the bolt.

Abstract: A cable bolt comprising a tension member having a first end and a second end. A rotatable collar is positioned on the tension member and is rotatable relative to the tension member. An elongate sheath, having a first end and a second end, is disposed over at least a portion of the tension member and secured to the rotatable collar. A method of securing an anchor in a structure is also disclosed.

Abstract: A cable bolt button comprising a continuous sidewall having a first end, a second end and an end portion attached to the first end of the sidewall, forming an inner cavity. The cable bolt button forms an interference fit between the sidewall of the cable bolt button and a cable bolt when the button is placed over the distal end of the cable bolt. The cable bolt button may also include a plurality of protrusions extending outwardly from the end portion away from the inner cavity and/or at least one recess. The protrusions may be separate features of the end portion or the first end of the sidewall may have a non-linear profile with the periphery of the end portion following the profile of the sidewall to form the protrusions and recesses. The end portion may also comprise a plurality of intersecting surfaces further shaping the protrusions and recesses.

Abstract: Disclosed is a rock bolt comprising an elongate shaft extending between opposite leading and trailing ends and a deformed section disposed proximal to the leading end, the deformed section being configured such that a protrusion extends outwardly beyond an outer surface of the shaft.

Abstract: A chemical anchoring assembly useful for fast application of a driving tool into a borehole includes an elongated tube having a first end and a second end, a quantity of chemical anchoring material within the elongated tube, and a vent at the second end of the elongated tube. As an anchor pin is driven through the elongated tube and into the borehole, forcing the chemical anchoring material into the borehole, some of the pressure caused by compression of the chemical anchoring material is released into the vent, allowing easier driving of the anchor pin.

Abstract: A filling apparatus for a grouting system. The filling apparatus comprises a first fill tube and a second fill tube. The first fill tube is discrete from the second fill tube. The first fill tube is disposed for transporting resin mastic and the second fill tube is disposed for transporting initiator. A portion of the first fill tube has an inlet opening through which an injection quill extends interiorly and downwardly through the first fill tube. The injection quill is disposed for transporting inhibitor. This disclosure also relates to a method for adjusting gel time of a grouting system used for anchoring a reinforcing member in an opening, a grouting system for anchoring a reinforcing member in an opening, and a method for anchoring a reinforcing member in a mine.

Abstract: An anchor bolt installation system comprised of a single-use capsule containing a mono-component anchoring substance for anchoring fastening articles to walls or similar structures. The present invention generally includes an open-ended capsule containing a plurality of apertures formed in an outer wall thereof. A mono-component anchoring substance is placed within a cavity in the capsule. A sleeve is positioned around the capsule and a cap is positioned to cover the opening of the capsule to prevent premature hardening of the anchoring substance. A guide member may be positioned within the opening of the capsule to guide and center a fastener being inserted therein. After removing the outer sleeve and cap, the capsule may be placed within a borehole. A fastener may then be inserted within the capsule, causing the anchoring substance to be excreted through the apertures of the capsule to firmly secure the capsule and bolt within the wall.

Abstract: A dry grout composition including a calcium aluminosulfate based hydraulic cement, a mineral filler, a thixotropic agent, and a superplasticizer agent. Also, an anchoring capsule, containing the dry grout composition, for use in anchoring reinforcing member dowel, or anchor elements in a hole of a substrate, and a method of use.

Abstract: An anchoring adhesive combination includes a slug or package of chemical anchoring adhesive having a proximal end and a distal end and a rod which can be a penetrator having a pointed proximal end, and open distal end, and a threaded or corrugated outer surface. The pointed proximal end of the penetrator is connected to the distal end of the slug or package of chemical anchoring adhesive so that the pointed proximal end is at least partially surrounded by chemical anchoring adhesive. The open distal end of the penetrator receives a proximal end of an anchor pin to form a combination of anchor pin, penetrator and slug or package of anchoring adhesive in series.

Abstract: A system including a chemical rock anchor and a device for injecting a fixative, the rock anchor including an anchor tube enclosing a cavity. The device includes at least one holding chamber containing the fixative, a tube into which the at least one holding chamber is integrated, permits injection of a fixative into a space between an anchor tube and a hole that has been drilled into the rock, while requiring little technical effort and permitting a controlled process. The tube can be inserted into the cavity, and/or the tube and the anchor tube are separate parts, and/or the tube is not attached to the anchor tube, and/or the system does not include any fastening means for the bonding and/or non-positive fastening of the tube to the anchor tube.

Abstract: A rock anchor includes an elongate tubular body which extends between a first end and an opposing second end and a cartridge contains a multi-component adhesive system in the tubular body. The cartridge has a rigid tubular housing within which at least one compartment is defined, and in which is contained an adhesive component of the system. The at least one compartment yields to volumetrically reduce under fluid pressure created by a fluid input into the housing, to thereby extrude the adhesive components.

Abstract: A filling apparatus for a grouting system. The filling apparatus comprises a first fill tube and a second fill tube. The first fill tube is discrete from the second fill tube. The first fill tube is disposed for transporting resin mastic and the second fill tube is disposed for transporting initiator. A portion of the first fill tube has an inlet opening through which an injection quill extends interiorly and downwardly through the first fill tube. The injection quill is disposed for transporting inhibitor. This disclosure also relates to a method for adjusting gel time of a grouting system used for anchoring a reinforcing member in an opening, a grouting system for anchoring a reinforcing member in an opening, and a method for anchoring a reinforcing member in a mine.

Abstract: A tensionable cable bolt including a length of multi-strand cable and an anchoring portion comprised of a shaft received on the cable and attached to the cable at a crimp portion comprising at least one primary crimp with at least one secondary crimp disposed within the primary crimp. The cable may include a mixing portion and the anchor portion may include an expansion anchor threaded onto the shaft. A method of manufacturing the tensionable cable bolt includes providing a length of multi-strand cable; providing an anchoring portion including a shaft; extending the cable through the shaft; and crimping the shaft to the cable to form at least one primary crimp with at least one secondary crimp disposed within the primary crimp. The method may further include threading an expansion anchor onto the shaft and/or providing a resin mixing portion along the cable.

Abstract: A system and method with a self-drilling chemical rock anchor bolt, specifically for use in the mining industry and a device for moving the rock anchor bolt, said rock anchor bolt comprising an anchor tube which encloses an interior, a fixation substance arranged within the interior for bonding the anchor tube on rock, a moveable piston arranged inside the interior for moving the fixation substance outside the anchor tube if the anchor tube is arranged in a borehole inside the rock, a boring head at one back end of the anchor tube, a rinsing channel to supply rinsing fluid, in particular rinsing water to the boring head, an expression channel to supply power fluid, in particular power water to the piston, is to be able to supply both rinsing water as well as power water into an interior of the rock anchor bolt with minor technical expenses.

Abstract: A method of forming a partitioned package for grouting for an anchoring system for a mine includes pumping a mastic into the package through a fill tube while a processing lubricant is separately introduced onto an inner wall of the fill tube.

Abstract: A rock bolt well adapted for use in mining is provided. The rock bolt includes an anchor tube that encloses an interior space, a fixing agent arranged inside the interior space for the substance-to-substance fixation of the anchor tube to stone, a mobile piston arranged inside the interior space for transporting the fixing agent out of the anchor tube when the anchor tube is arranged in a bore hole in the stone, a piston moving mechanism, an anchor nut, and an anchor plate supported by the anchor nut for support on the stone.

Abstract: A mine roof bolt includes an elongated body, first and second nuts, and an end fitting. The elongated body has a first end and a second end with the first end having a threaded portion. The first and second nuts are positioned on the threaded portion of the first end of the elongated body. The end fitting is positioned on the threaded portion of the first end of the elongated body between the first and second nuts.

Abstract: A partitioned package includes an inner tube having a longitudinally extending seal and containing a first material, and an outer tube having a longitudinally extending seal and surrounding the inner tube and containing a second material. The seals of the inner and outer tubes are positioned at different radial locations.

Abstract: Provided are an anchor fixing agent which can fill up fine concave and convex portions present on the inner surface of a hole formed in a base material and can maintain great strength, in particular, even after the lapse of a long period of time; an anchor fixing agent ampule; and a method for fixing an anchor. An anchor fixing agent which comprises an alumina cement, a lime and/or a portland cement, and water. Preferably, it further comprises an agent for the retardation of setting and light magnesia. The anchor fixing agent ampule holds a solid component and a liquid component in the anchor fixing agent in the state wherein the components are separated from each other.

Abstract: A fastening element (11) for anchoring in a borehole (7) with a hardenable compound (31) has a shaft (13) extending along a longitudinal axis (12), a mixing element (22), and a profiling element (26) with radially protruding profiling sections.

Abstract: A tensioning assembly 10 for a cable bolt 11 comprises a clamping device (14, 16) adapted for fastening to the bolt and an outer member 18 adapted for interacting with the clamping device. The outer member 18 is able to undergo relative movement to the clamping device in the direction of the bolt's axis, and under such movement, the clamping device is caused to fasten to the bolt. Furthermore, the outer member is adapted for interacting with the bolt 11 whereby, during such relative movement, twisting of the bolt 11 with respect to the outer member 18 is restrained.

Abstract: An adaptor for setting a self-drilling, chemically anchorable, fastening element (5) includes a rotor member (21) rotatably supported in the adaptor housing (36) and having at its opposite ends (23,25) respectively, a coupling section (24) for connecting the rotor member (21) with a drilling tool (8) for joint rotation therewith, and a coupling receptacle (26) for fixedly receiving a free end (6) of the fastening element (5). Support elements (52,53) are provided in one of two housing parts (41,51) for rotatably supporting the rotor member (21). Sealing elements (42), which are provided in another housing part (41), for a connection channel section (32) that connects a connection opening (37) in the housing (36) for the ejection medium (4) with a feeding channel (31) in the rotor member (21).

Abstract: A tensioning assembly 10 for a cable bolt having a flexible shaft 12 comprises a clamping device 14, 16 configured to mount to the bolt shaft 12 with an axis (CA) of the clamping device aligned with the shaft axis (SA); and an outer member located over, and engaged with, the clamping device 14, 16. The outer member 18 is arranged, under a predetermined movement of the outer member, to impart drive to the clamping device 14, 16 to bias the clamping device 14, 16 to move in the direction of the clamping device axis. A cable bolt and method of tensioning a cable bolt is also disclosed.

Abstract: A mine roof bolt includes an elongated rod and a polymer coating layer. The elongated rod has a first end and a second end with a protruding portion extending radially outward from the elongated rod. The polymer coating layer covers at least a portion of the elongated rod between the first and second ends. The elongated rod is movable relative to the polymer coating layer in an axial direction. The elongated rod has a first position where the elongated rod has a predetermined axial position relative to the polymer coating layer and a second position where the elongated rod has a displaced axial position relative to the first position.

Abstract: A bolt includes a tube, at least a portion of which is hollow, having a top and the bottom and at least one dimple. The bolt includes an insert fixed to the interior of the tube in proximity to the dimple with the dimple disposed between the insert and bottom of the tube. A method for a bolt includes the steps of inserting a resin cartridge into a hole. There is the step of inserting the bolt into the hole. There is the step of placing a top end of a installation tool into a hollow tube of the bolt. There is the step of moving the tool up, which pushes the tube upwards, causing the resin cartridge to break. There is the step of rotating the top end of the tool, which causes the tube to rotate and mix the resin. There is the step of holding the top end of the installation tool inside the tube until the resin hardens and a resultant tension remains on the bolt. An installation tool. A method for forming an installation tool.

Abstract: A resin insertion device includes a barrel, a piston within the barrel, and a triggering mechanism. The triggering mechanism includes an air outlet, an air inlet, a venturi tube and at least one trigger piston. A resin insertion device includes a barrel having a collar disposed at a first end and a piston disposed slidably within the barrel. A triggering mechanism is disposed at a second end. A first position of the trigger prevents airflow through an air inlet, a second position allows air through the inlet and an outlet, and a third position prevents airflow through the outlet. A method of inserting resin into a bore hole includes providing an insertion device including a barrel, and a triggering mechanism. The method includes depressing a trigger from a first to a second position, placing at least one resin cartridge within the barrel, and further depressing the trigger.

Abstract: A setting method of anchoring a fastening element (11; 41) in a constructional component (21) with a hardenable multi-component mass (31) includes drilling a borehole (22) in the constructional component (21) with a drill (36) until a borehole depth (T), which is at least by 5% greater than a necessary anchoring length (L) of the fastening element (21; 41), is reached; introducing the hardenable multicomponent mass (31) in the uncleaned borehole (22), inserting, in the borehole (22) the fastening element (11; 41) with its mixing section (13; 43) first, and power-driving the fastening element (11; 41) into the filled borehole (22) with a rotary driving tool, with intermixing of the hardenable multi-component mass (31) with drillings (23) remaining in the borehole (22), until the necessary anchoring length (L) of the fastening element (11; 41) is reached.

Abstract: A method of adjusting gel time of a grouting system used for anchoring a reinforcement in a mine includes adding inhibitor to initiator of the grouting system, the inhibitor and initiator being disposed together in a first compartment of a multi-compartment shreddable package.

Abstract: An improved ground support member insertion device comprising means for attaching the device to a jackleg drill, a clutch assembly disposed adjacent to the attaching means and adapted for holding a ground support member while it is being inserted into a first drill hole; and, anchoring means disposed opposite the clutch assembly and adapted for temporarily anchoring the device for stabilization in a rock formation during insertion of the ground support member. An impact tool for engaging the proximate end of the ground support member providing rotation and impact to the ground support member to mix the resin and to secure the ground support member in a rock formation. The impact tool can also be used to manually or mechanically tension the ground support member once installed.

Abstract: The resin anchor comprises an apertured tubular envelope designed to be compressed by a traction element, characterized in that it includes, on the inside of the envelope, a resin component and a hardener component that are intended to be mixed together and to cure under the action of the compression of the envelope, in order to fasten the anchor. The traction element is a stud having a threaded rod part that cooperates with a tapped traction element firmly attached to the end of the bushing. The anchor is fastened both mechanically and chemically, for either solid material or hollow material.

Abstract: The resin nozzle adapted for storing resin set bolts into ceilings and walls of a mine by injecting a resin sausage into a pre-drilled bolt hole, the said nozzle including: a spring that defines a passage to which resin sausages may be passed there-through; a nozzle tip connectable to the same defined passage, said nozzle adapted to extend into a pre-drilled bolt hole; and a connector member adapted to be fastened onto the tuck bolting equipment to which the resin sausages may be ejected there-from.

Abstract: An adaptor for setting a self-drilling, chemically anchorable, fastening element (5) includes a rotor member (21) rotatably supported in the adaptor housing (36) and having at its opposite ends (23, 25) respectively, a coupling section (24) for connecting the rotor member (21) with a drilling tool (8) for joint rotation therewith and a coupling receptacle (26) provided for fixedly receiving a free end (6) of the fastening element (5), support elements (52, 53) provided in one of two housing parts (41, 51) for rotatably supporting the rotor member (21), and sealing elements (42) provided in another housing part (41) for sealing a connection channel section (32) that connects a connection opening (37) in the housing (36) for the ejection medium (4) with a feeding channel (31) in the rotor member (21).

Abstract: A resin insertion device includes a barrel, a piston within the barrel, and a triggering mechanism. The triggering mechanism includes an air outlet, an air inlet, a venturi tube and at least one trigger piston. A resin insertion device includes a barrel having a collar disposed at a first end and a piston disposed slidably within the barrel. A triggering mechanism is disposed at a second end. A first position of the trigger prevents airflow through an air inlet, a second position allows air through the inlet and an outlet, and a third position prevents airflow through the outlet. A method of inserting resin into a bore hole includes providing an insertion device including a barrel, and a triggering mechanism. The method includes depressing a trigger from a first to a second position, placing at least one resin cartridge within the barrel, and further depressing the trigger.

Abstract: A resin bonded mine roof bolt having an elongated rod with a first end, a second end, and a resin control surface positioned on the rod between the rod first and second ends. The resin control surface has a channel extending along the length of the bolt for distributing resin and interrupted spiral threads for mixing resin. When installed in a mine roof bore hole with curable resin, the resin control surface mixes the resin and partially fills the bore hole to minimize the amount of resin needed to anchor the bolt.

Abstract: An expansion anchor assembly for a mine roof bolt having a tapered plug, expansion leaves, a bail and a removable holding ring configured to hold the expansion anchor assembly in an assembled position is disclosed. The tapered plug is configured to be threaded onto the mine roof bolt and defines plug channels to encourage symmetrical resin flow past the tapered plug. The bail defines a medial opening through which the mine roof bolt extends.

Abstract: A bolt assembly for insertion into a rock wall including a hole having a diameter an a method thereof are provided. The assembly includes a resilient cylinder for insertion into the hole, a shaft for insertion into the cylinder, a grouting material for retaining the shaft within the cylinder and stiffening the assembly, and coupling means for coupling the extremity of the cylinder to the extremity of the shaft. The cylinder has a diameter which is greater than the diameter of the hole when the cylinder is uncompressed. In this manner, the cylinder is radially compressed when inserted into the hole and thereby frictionally engages the hole. The cylinder has an extremity extending outside the hole when it is inserted therein. The shaft includes an extremity which extends outside the hole when the shaft is inserted into the cylinder in an operating position.