Abstract: A protective device for a pressurized gas tank comprises a shell designed to absorb energy in the event of an impact and a mechanical joining interface to mechanically join the shell to the pressurized gas tank.

Abstract: The present disclosure refers to a system and components for a thief hatch. The thief hatch may include a flange body comprising a first composite material. The flange is configured to attach to a tank roof. A lid is operably connected to the flange body. The lid comprises a second composite material. The lid comprises a hinge operably connected to allow for at least partial opening and closing of the lid. The first composite material and the second composite material are the same material or different materials.

Abstract: A tank for pressurized gas such as hydrogen, comprises a paste sealant, a sealing envelope, and a base comprising a recess accommodating a neck. A substantially annular external cavity is between a convex surfaces of the neck and a concave surfaces of the recess A substantially annular inner cavity is between a concave surface of the neck and a convex surface of the recess. The paste sealant occupies the annular external and annular inner cavities uniformly and thus ensures the mechanical strength and the gas seal between the sealing envelope and the base. The sealing envelope comprises a body and a neck on the surfaces of which at least two angularly equidistant protrusions extend radially.

Abstract: This high-pressure tank includes a resin liner constituting a hollow fluid filling part, a ferrule including a supply/discharge port which communicates with an internal space of the liner and a flange part which protrudes outward in a radial direction from a circumferential region of the supply/discharge port and abuts on the liner, and a reinforcing layer made of a fiber reinforced resin attached to cover across the liner and an outer circumferential surface of the flange part, in which a discharge hole allowing a gap between abutting surfaces of the flange part and the liner to communicate with an inside of the supply/discharge port and discharging a fluid accumulated between the liner and the reinforcing layer to the supply/discharge port is provided in the ferrule, and a trap groove surrounding a circumferential region of the discharge hole is provided on at least any one of the abutting surface on the flange part side and the abutting surface on the liner side.

Abstract: A composite gas storage tank includes a composite wall defining a main storage volume and a hollow conduit portion communicating with and extending away from the main storage volume. A hollow coupling element has a length portion which is partially embedded within and extends substantially parallel to the hollow conduit portion of the composite wall. The hollow conduit portion and the coupling element provide communication between the main storage volume and the tank exterior. A leakage path around the hollow coupling element is significantly longer than those of tanks of the prior art and reduces the rate at which hydrogen leaks from the tank. A carbon fibre filament winding extends over the length of the hollow conduit portion and provides a radially inwardly-directed force biasing the carbon fibre material of the hollow conduit portion into contact with the coupling element, further reducing the leakage rate on the leakage path.

Abstract: An integrally-formed liquid collecting box structure and a method for manufacturing the same are presented. The integrally-formed liquid collecting box structure includes an integrally-formed liquid collecting box, a screw, and a leak-proof sealing ring. The leak-proof sealing ring is located between a nut portion of the screw and an inner end face of a stepped hole. The screw is screwed into an internal threaded hole. When the screw is tightened, the nut portion squeezes the leak-proof sealing ring so that the leak-proof sealing ring is deformed and clamped between the nut portion and the inner end face of the stepped hole, so as to prevent leakage.

Abstract: A tank includes a liner that includes a barrel portion in a cylindrical shape and a pair of dome portions provided at both ends of the barrel portion in the axial direction, and a reinforcing layer that covers the liner and that is formed from a fiber reinforced resin formed by impregnating a fiber bundle with a resin. A portion of the reinforcing layer that covers the dome portions includes a radial arrangement layer in which fibers of the fiber bundle are arranged radially along the radial direction of the dome portions when seen in the direction of an axis of the tank.

Abstract: A container assembly comprises a container and a base and is configured to be transported horizontally to a work site where it is raised to a vertical working orientation. A hoppered container floor directs material to a discharge opening in a center of the floor of the container. A plurality of chutes is fixed to the container assembly and each slopes downward and outward from a chute input, located under a central portion of the hoppered floor, to a corresponding chute output. A distributor assembly mounted under the discharge opening receives granular material from the discharge opening and directs same into any one of the chute inputs. When loaded on a gooseneck trailer the container extends over the hitch assembly providing increased volume and capacity.

Abstract: The invention concerns a machine for manufacturing plastic items comprising, in series, along the manufacturing line: a rotatable roll (1) of plastic material in the form of at least one strip; a shaper (4) for forming tubes from said strips and means (5) for longitudinally welding said tubes; means (6) for cutting the tubes transversely, arranged so as to form tube sections (10); means for transferring and depositing said sections in holding and moving means; an oven (8) in which said tube sections move; a first turret (9) supporting moulds; means for processing the tube sections in the first turret; means for blowing a pressurised fluid into the moulds; a second turret (14) for discharging the bottles from said moulds.

Abstract: A boss includes a neck and a flange that extends radially outward from the neck. The neck includes a bore therethrough with a longitudinal axis. The flange includes an exterior surface, an interior surface, and a peripheral surface at a farthest extent from the longitudinal axis. The peripheral surface connects the interior surface and the exterior surface and includes, along any radius of the boss, a first circumferential ridge and a second circumferential ridge, wherein the first circumferential ridge is located closer to the exterior surface than the second circumferential ridge. In another aspect, a pressure vessel includes a boss and a liner. In yet another aspect, a method of assembling a pressure vessel is described, which includes inserting the boss through the aperture of the liner and connecting the boss and liner so that the peripheral surface of the boss mates with the perimeter surface of the liner.

Abstract: A bung plug closure (30) for fastening a plug depression formed in a bung plug (31), said plug depression comprising a receiving area for receiving a resilient engagement body realized on the seal cap (11), and said bung plug (31) comprising tool engagement projections (33), which are arranged on an inner wall of the plug depression and which are distanced to each other via gaps (34) and which delimit the receiving space using inner surfaces (37), counter-locking elements (32) being provided in the plug depression, said counter-locking elements (32) being arranged in the area of the gaps (34) above an annular frame (35, 61), which is formed outside of the gaps (34) via lower sections (36) of the inner surfaces (37).

Abstract: A holder rack has an array of tubular slots that cooperate with a holder to position an absorbent tip of the holder at a predetermined location. The racks fit over well plates to position each absorbent tip adjacent the bottom of a different well in the well plate to extract dried samples from the absorbent tips. The holders are transported in containers having a frame to receive the holders and a lid to keep them in the container. The absorbent tips can extend through a cap to dry, with the cap connected to the holder to enclose the absorbent tips for transport.

Abstract: A boss includes a neck and a flange that extends radially outward from the neck. The neck includes a bore therethrough with a longitudinal axis. The flange includes an exterior surface, an interior surface, and a peripheral surface at a farthest extent from the longitudinal axis. The peripheral surface connects the interior surface and the exterior surface and includes, along any radius of the boss, a first circumferential ridge and a second circumferential ridge, wherein the first circumferential ridge is located closer to the exterior surface than the second circumferential ridge. In another aspect, a pressure vessel includes a boss and a liner. In yet another aspect, a method of assembling a pressure vessel is described, which includes inserting the boss through the aperture of the liner and connecting the boss and liner so that the peripheral surface of the boss mates with the perimeter surface of the liner.

Abstract: A spout includes a mounting portion to which a pouch of a container assembly is sealed. The exterior of the mounting portion is defined by a smooth, non-angled surface free of edges or sharp transition portions, and is defined along its height by a generally sinusoidal, wave-like pattern formed by alternating peaks and troughs. The exterior of the mounting portion is structured such that the ratio of the length of the portion of the mounting portion exterior surface extending between adjacent peaks to the height between adjacent peaks is minimized to no more than 10%, and more preferably no more than 5%. By minimizing this ratio, the amount that a pouch will stretch if it is pushed into the cavities formed between adjacent peaks of the mounting portion (e.g. during an HPP process) is minimized, thereby preventing damage to the pouch and/or attachment between the pouch and spout.

Abstract: The present disclosure provides a chemical container and a method for manufacturing the same. The chemical container comprises a head portion having a top wall and a head sidewall extending from an edge of the top wall, as well as a body portion jointed with the head portion and defining a chamber together with the head portion. The top wall has a mouth structure configured for one or more pipelines to pass through and connect with the chamber. The manufacturing method is simple and of low cost, and the resulted chemical container is able to withstand a greater internal pressure and is configured to collect any leaking liquid chemicals.

Abstract: An embodiment of the present invention relates to a produce container which includes a receptacle and a lid. The receptacle has a base and a wall defining a mouth. The base includes a first engaging portion and a lid adapted to close off the mouth. The lid has a top having a second engaging portion adapted to cooperate with the first engaging portion of another identical produce container so as to facilitate interlocking of the container with the other identical container.

Abstract: Described herein is an improved container for storing, shipping, and dispensing proppant materials used in hydraulic fracturing operations. The container systems incorporate stretchable hopper structures in the container. The hopper expands and contracts responsive to the amount of proppant material held in the container. When the container is filled with a sufficient amount of proppant, the hopper stretches to expand the storage volume. When the sufficient amount of proppant material is dispensed from the container, the hopper contracts to lift and dispense the container contents.

Abstract: A bulk material shipping container in one embodiment including a pallet, a bottom compartment mounted on the pallet, a top compartment mounted on the bottom compartment and movable from a retracted position relative to the bottom compartment to an expanded position relative to the bottom compartment, a plurality of top compartment supporting assemblies configured to support the top compartment in the expanded position relative to the bottom compartment, and configured to release the top compartment from the expanded position to enable the top compartment to move downwardly into the retracted position, a material unloading assembly, a material loading assembly, and an extension assembly.

Abstract: Drums of thermoplastic synthetic material include a circumferentially extending carrying and transport ring arranged on the drum wall in the vicinity of the upper bottom, and at least one bunghole connection sleeve arranged in a trough-shaped indentation of the upper head of the drum in the area of the rim thereof. An integrally formed stiffening bead is arranged on the inner side of the carrying and transport ring of a drum of the above-described type in the vicinity of a bunghole connection sleeve. A stiffening hump is formed in the upper head of the drum between the stiffening bead of the carrying and transport ring and the bunghole connection sleeves.

Abstract: Provided is a method for filling a container with a liquid in which the container is filled via an opening of the container and an internal volume of the container increases during the filling process and the internal volume of the filled volume is at least twice the volume of the unfilled container. Also provided is a device for filling containers, and a container having an opening, a base region, and a main body integrally formed with the opening and the base region, the main body being bent by a specified bending angle around a specified circumferential folding edge of the main body in such a way that the opening of the container is arranged closer to the base region than the circumferential folding edge is, wherein the position of the folding edge relative to the base region of the container can be changed during an expansion of the container.

Abstract: A laminated sheet construction for use in product packages has a substrate layer onto which there is laminated a transparent solid plastic film with an exposed surface having a transparent thermosetting adhesive coating. The surface beneath the coating may be printed with text and/or graphics which is visible through the film and adhesive. A container for a product may be directly affixed to the adhesive surface. Panels of the laminated substrate may be bonded together for increased strength or for capturing the flange of a container which can project through a window in one of the panels while displaying printing on the other panel through the window.

Abstract: A cover for an electronic device includes a transparent portion and a non-transparent portion beside the transparent portion. The transparent portion defines a display area of the electronic device. The non-transparent portion defines a non-display area of the electronic device beside the display area. The non-transparent portion includes a transparent substrate integrated with the transparent portion. A plurality of through holes are defined on the transparent substrate.

Abstract: A packaging box, cutouts, method and device for producing corrugated cardboard boxes comprising walls, a base (6) and a cover (7), the inner face of the base being provided with at least two recesses (33) and the cover comprising at least two tabs (38) adhered to the upper face thereof, directly above the recesses of complementary shape. The recesses and/or the tabs are situated fully inside the corresponding face or faces (31, 32).

Abstract: An injection port is provided for installation on an enclosure to provide quick access for admitting a fire suppressing agent into the enclosure in the event of a fire inside the enclosure. The injection port includes a housing and an injection port cover. The housing includes a mounting plate for mounting the housing to the enclosure and a pin receptacle. The injection port cover includes a cover plate and a pin release mechanism. The pin release mechanism includes a movable pin that engages with the pin receptacle of the housing to secure the injection port cover to the housing when the injection port is in the closed position.

Abstract: An apparatus for receiving a fluid is disclosed. The apparatus comprises an at least partially flexible vessel. The vessel includes a top wall and a plurality of sidewalls, a first of said sidewalls having a first length in a first plane that is greater than a second length of the second, generally orthogonal sidewall in the first plane, and a bottom wall depending from the at least two sidewalls. The vessel may have a generally rectangular cross section, and may include a depending portion. The vessel may be at least partially rigid. Related methods are also disclosed.

Abstract: A vacuum insulation panel assembly having upper, lower, and first and second side vacuum insulation panels. The upper vacuum insulation panel has an aperture formed therethrough and an edge forming an overlap joint. The lower vacuum insulation panel also has an aperture formed therethrough and an edge forming an overlap joint. The first and second side vacuum insulation panels have an arcuate, half-cylindrical shape with a top edge forming an overlap joint configured to engage the overlap joint of the upper vacuum insulation panel, a bottom edge forming an overlap joint configured to engage the overlap joint of the lower vacuum insulation panel, and first and second side edges forming overlap joints configured to engage the overlap joints of the first and second side edges of the other side vacuum insulation panel.

Abstract: A storage tank including a frame and a tank assembly. The tank assembly including a vessel supported by the frame and having a first end, a second end, and a polygonal sidewall extending from the first end to the second end. The vessel further having a top, a bottom, at least one side, and an internal surface, and an outlet fluidly coupled with the bottom; and a chemical-resistant lining associated with the internal surface of the sidewall and being substantially flexible. The frame is configured to support the tank assembly so that the bottom of the vessel is elevated a distance above a surface to allow for visual inspection of the top, bottom, and the at least one side of the sidewall.

Abstract: A system for storing high level radioactive waste. In one embodiment, the invention can be a system comprising an overpack body extending along a vertical axis and having a cavity for storing high level radioactive waste, the cavity having an open top end and a floor; an overpack lid positioned atop the overpack body to enclose the open top end of the cavity; an air inlet vent for introducing cool air into the cavity, the air inlet vent comprising an annular air inlet plenum and an annular air inlet passageway, the annular air inlet plenum extending radially inward from an outer surface of the overpack body to the annular air inlet passageway, the annular air inlet passageway extending upward from the annular air inlet plenum to an opening in the floor, and an air outlet vent in the overpack lid for removing warmed air from the cavity.

Abstract: A bulk material shipping container in one embodiment including a pallet, a bottom compartment mounted on the pallet, a top compartment mounted on the bottom compartment and movable from a retracted position relative to the bottom compartment to an expanded position relative to the bottom compartment, a plurality of top compartment supporting assemblies configured to support the top compartment in the expanded position relative to the bottom compartment, and configured to release the top compartment from the expanded position to enable the top compartment to move downwardly into the retracted position, a material unloading assembly, a material loading assembly, and an extension assembly.

Abstract: A drainable container system for a vehicle includes a container having an exterior surface and defining an interior cavity configured for storing a fluid, and a drain hole configured for draining the fluid from the cavity. The hole has a central longitudinal axis that is substantially perpendicular to the surface. The system includes a drain plug, wherein the plug is insertable into the hole along the axis into a locked position so that the fluid does not drain, and removable from the hole along the axis when disposed in an unlocked position so that the fluid drains. The system includes a locking element configured for preventing rotation of the plug within the hole about the axis when the plug is disposed in the locked position, wherein the element is formed from a metal that is substantially elastic at a temperature of from about ?40° C. to about 10° C.

Abstract: A membrane for sealing an open spout of a food package comprises a central circular disc member, an outer annular disc member connected to the central circular disc member along its inner periphery at a connection angle, and a resilient tubular portion extending between a first open end and a second end being connected to the outer annular disc member, the diameter of the second end being smaller than the outer diameter of the annular disc member, wherein the annular disc member is pivotable relative the central circular disc member for increasing the diameter of the second end of the tubular portion by changing the connection angle.

Abstract: A crate includes a base and a plurality of walls including a front wall. The front wall is movable between a retracted, open position and a closed position. In some embodiments, the front wall includes a frame, a first portion and a second portion. The first portion is hingeably connected to the frame and the second portion is hingeably connected to the first portion.

Abstract: The object of the present invention is to provide a sealing structure which enables an insertion member to be removed easily from an inserted member. The sealing structure includes valve body, a mouth ring, an O-ring that is accommodated in an accommodation region formed by an inner peripheral surface of the mouth ring and an outer peripheral surface of the valve body, and prevents the fluid from leaking, and backup rings which are accommodated on both sides of the O-ring in the accommodation region, and restrict a movement of the O-ring. The valve body and the mouth ring are formed with screw parts to be fitted or screwed to each other when they are assembled, and first pressure release grooves are formed in the axial direction so as to extend at least on the inner peripheral surface of the mouth ring between the screw parts and the accommodation region.

Abstract: The present invention provides a tank including an O-ring 34 between a cylindrical mouth portion 18, which is formed in a resin liner 12 forming a tank body which is to be filled with gas, and a ferrule member 20 which is mounted on an inner peripheral side of the mouth portion 18. An insert ring 36 which is insert-molded at the time of molding the resin liner 12 is provided within the mouth portion 18. The insert ring 36 includes a plurality of communication holes 38 which communicate between the inner peripheral side and an outer peripheral side thereof.

Abstract: A semen container fitted with a specialized tip includes a substantially hollow body having a sealable first end adapted for the introduction of biological fluids such as semen and a second end having a nozzle molded thereto. The nozzle terminates in a removable tip that is anchored to the container by way of a tab such that after dispensing the biological liquid from the container the tip and the container may be disposed of simultaneously thereby reducing or eliminating the need to separately collect the removed tips from the ground.

Abstract: A tray for transporting and displaying baked products is disclosed. The tray can be stacked in a 0° and 180° stacking configuration. The trays further include substantially non-glossy, non-smooth surfaces that allow stickers to be more easily removed, as well as drain channels in the base to facilitate removal of water following washing. The trays further include a scalloped handle on one side of the tray only to allow operators to more easily recognize which side of the tray they are facing. A tray retrieval tool can be used with several hook areas to facilitate retrieval of the trays following washing in high temperature water, or following stacking and storage. The trays further include spacers and spacer holes to place the spacers so that different types of baked products can be accommodated without damaging or destroying the baked product.

Abstract: A pressure vessel for storing a fluid, the pressure vessel including an annular inner boss having an inner surface and an outer surface, the inner surface forming a passage adapted to receive a utility device therein, wherein the inner boss includes a liner channel formed intermediate the inner surface and the outer surface, a vessel liner having a portion thereof disposed in the liner channel of the inner boss, and an outer boss secured to the outer surface of the inner boss.

Abstract: A transportable container apparatus includes an elongate container with a base. The container and base are substantially symmetrical about the central axis, typically cylindrical, and oriented substantially vertically when in a working position. The container has an upper container section and a lower container section, where the upper container section has an upper cross-sectional area that is greater than a lower cross-sectional area of the lower container section. Typically the upper section has a diameter 1.5-2.0 times the diameter of the lower section. The upper section includes a sloping hopper at a bottom thereof, configured to direct granular material into the lower container section. An outlet port is defined in a ported wall of the lower container section, and a floor of the container is sloped toward the outlet port such that granular material stored in the container slides down the floor to the outlet port.

Abstract: A cartridge is provided having at least one reception chamber (2), which extends in the longitudinal direction, for a medium to be dispensed, having a head part (4), a base part (6) and a cartridge wall (3) which bound the reception chamber (2), with the head part (4) having an outlet (5) for the medium. The cartridge wall (3) is designed as a film (3), the head part (4) and the base part (6) in each case as fixed shape parts and the head part (4) is sealingly and non-releasably connected to the cartridge wall (3). A multicomponent cartridge is furthermore provided by the invention.

Abstract: A tray for vibratory conveying of food articles from a hopper is provided. The tray includes a tray body, food inlet portion, and a food outlet portion. An upwardly extending dividing member divides the tray into at least two food inlet conveyor passageways, the inlet conveyor passageways merging into a single food passageway that extends to the food outlet portion. The single food passageway may have an initially wide portion and subsequently narrow to a narrow portion as it approaches a discharge end. This arrangement helps to declump food items, preferably causing food items the size of chicken nuggets to be conveyed in a single-file arrangement along the single food passageway. The single food passageway is preferably non-linear, and may, for example, have a zigzag or serpentine configuration to promote accurate dispensing of food items.

Abstract: A method and apparatus for venting and compressing a fluid. The apparatus comprising a valve having a vent and a compressible element attached to the vent. The vent and the compressible element define a flow-through channel therein. The compressible element has an internal space adapted to be elastically compressed and expanded. The valve is further adapted to regulate a pressure in a container when a predetermined pressure is applied to the compressible element of the valve.

Abstract: A fluid container and method of manufacture. The fluid container may be a drinking vessel, and may include an opening in a bottom surface thereof and a coupling device around the opening. The coupling device may include a first component in contact with the bottom surface of the fluid container around the opening and a second component in contact with the first component in a fluid-tight closed configuration. The second component may include a magnetic material. The coupling device may be biased in the fluid-tight closed configuration via magnetic attraction of the first and second components.

Abstract: A heat-sealable, plastic bottle with an internal scraper and an inner seal is described. More particularly, the present application relates to a heat-sealable, plastic bottle having an opening with an internal scraper chord that is less than or equal to the diameter of the circular opening, an inner seal, and a cap.

Abstract: A wide-neck drum of thermoplastic material has a removable cover and a clamping ring closure. The drum is provided with an arrangement of a bung socket of a filling and discharge bung of the cover which is outwardly offset relative to the center point of the bung cover. The bung is provided at a flat or slightly curved bottom which has an upwardly protruding cover rim for fastening the bung cover on the drum opening rim.

Abstract: A bucket sump system for use with a liquid which includes a bucket having an interior comprising: sides defining an open top and coupled to a flat bottom, and a wedge insert received by the interior of the bucket, resting flush against the flat bottom of the bucket. The wedge insert has a flat bottom portion, a sloped top surface connected to the bottom portion through a first side having a first height and a second side having a second height, and an orifice defined by the first side of the wedge insert. The liquid received by the interior of the bucket flows from the second side of the sloped top portion of the wedge insert to the first side of the sloped top portion of the wedge insert and into the orifice. The second height of the wedge insert is greater than the first height of the wedge insert.

Abstract: A threaded weld fitting and a method of welding a threaded weld fitting to the tank wall of a water storage tank are provided. The threaded weld fitting comprises a body defining an aperture and having a facing surface configured to be positioned facing the tank wall. A female thread is formed along the aperture. A first beveled surface portion of the facing surface extends from an edge of the body. A landing surface portion of the facing surface extends from the first beveled surface portion toward a longitudinal axis of the aperture. A second beveled surface portion of the facing surface extends from the landing surface and to the female thread. The landing surface portion and the second beveled surface portion together define an open annular area positioned to receive a portion of a weld formed by welding the threaded weld fitting to the tank wall.

Abstract: A serviceable draw and return tube assembly for use in fuel tanks is disclosed. The assembly may include a draw tube and a return tube secured to a plate, wherein the plate may be removably secured to a flange, which is fixedly secured to a fuel tank. The process of removably securing the plate to the flange allows for use of different sizes and materials to be utilized in manufacture of the assembly, thereby saving installation time and manufacturing costs.

Abstract: A liner (10) is disclosed for use with a container. The liner has a liner body (11) with a bottom wall (13), a top wall (14) and peripheral side walls (15). The liner also includes a ween plate (21). The weep plate includes a radial array of protrusions (22) extending inwardly and downwardly from a generally planar base plate (23). The base also includes a centrally located circular fitment mounting opening (25). A hose fitment (29) extends through the liner top wall and weep plate fitment mounting opening and is sealed thereto so that a vacuum hose coupled to the fitment is in fluid communication with the interior space of the liner. The weep plate has a select width and length smaller that the select width and length of the liner to define a margin or marginal space (32) therebetween.

Abstract: A closure assembly for a container including an internally-threaded annular flange, an externally-threaded closure plug that is received by the annular flange, and an annular gasket positioned between the annular flange and the closure plug for establishing a sealed interface. The container includes a container end panel that is formed over and around a portion of the annular flange and provides an inner axial wall that is positioned between the annular flange and the annular gasket. The clearance between the closing plug and the inner axial wall relative to the size of the annular gasket determines the degree of radial compression of the annular gasket as the plug is threaded into the flange. A radial lip of the plug is designed to contact an upper surface of the container end panel that is formed over the flange as a visual indication when the required tightening torque of the plug within the flange has been reached.

Abstract: A drainage system is provided for draining liquid accidentally spilled on a casing having a plurality of pushbuttons on a surface of the casing. The drainage system for a pushbutton casing may comprise a liquid collecting receptacle, a counter-bore, and a drainage exit. The counter-bore may have a sidewall. The liquid collecting receptacle may be operatively interfacing the casing. The drainage exit may be disposed on the sidewall of the counter-bore. An end opening of the counter-bore may be in connection with a drainage exit. The end opening of the counter-bore may be disposed to allow liquid entering the drainage exit out of the end opening of the counter-bore.